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Infanticide linked to wet-nursing in meerkats

Subordinate female meerkats who try to breed often lose their offspring to infanticide by the dominant female or are evicted from the group. These recently bereaved or ostracised mothers may then become wet-nurses for the dominant female, an activity that may be a form of “rent” that allows them to remain in the community. Wet-nursing another mother’s offspring — called allolactation — occurs across a variety of mammals and is thought to provide survival benefits to the nursed offspring and to the mother of the pups. However, little has been definitively known of why the females who provide the wet-nurse service do so. Now, in the most comprehensive study conducted to date, researchers studying a meerkat population in the Kalahari region of South Africa have identified factors that influence why females might wet-nurse. The findings, published today in Animal Behaviour, show that females are more likely to allolactate if they have recently lost litters or have returned to the group following eviction. “Breeding opportunities are monopolised by a single behaviourally dominant female in meerkat groups,” explains Kirsty MacLeod, who carried out the research at the University of Cambridge’s Department of Zoology with Professor Tim Clutton-Brock, and Johanna Nielsen at the University of Edinburgh. “She maintains this position through suppressing breeding attempts by other females — either through evicting them or killing their pups — and these subordinate females are then also more likely to wet-nurse the dominant female’s pups. This suggests to us that infanticide by the dominant female might have two evolutionary advantages for her — she reduces competition for care for her own pups, and is more likely to secure allolactation for her litter.

“Wet-nursing by formerly evicted meerkats may be a way of ‘paying rent’ to be allowed back into the group without receiving further aggression,” she adds. Helping as payment of ‘rent’ has been suggested in bird species in which helpers receive greater benefits from remaining in their territories owing to a lack of opportunity to attract a mate from elsewhere, but has previously been suggested in only one other mammal — the naked mole rat. The research was carried out over a 15-year period, with 40 social groups of meerkats being observed. The researchers created a long-term database and recorded, among other life-history details, pregnancies and lactation periods. Because most pup nursing occurs below ground, females were identified as producing milk through the presence of suckle marks and the attachment of sand to damp nipples. “Now that we have a clearer idea of which females are more likely to invest energy in this highly cooperative behaviour,” says MacLeod, “our next step is to figure out what benefits each party is getting from this. We know that lactation is costly, so it’s likely that if additional females also provide milk, those costs should go down. We’ll know that soon. “These results, however, hint at what the benefits might be for subordinate allolactators. Because subordinate females were more likely to allolactate if they are related to the litter’s mother, this suggests that they may gain an indirect benefit from the activity. Evictees from the group suffer considerable stress, weight loss and reduced survival. If contributing to the maternal cares of another’s offspring allowed renewed access to the social group, or to remain in the group once following infanticide, there would be an incentive to ‘pay-to-stay’.”

Science Daily
October 29, 2013

Original web page at Science Daily

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Part of brain that makes humans and primates social creatures may play similar role in carnivores

The part of the brain that makes humans and primates social creatures may play a similar role in carnivores, according to a growing body of research by a Michigan State University neuroscientist. In studying spotted hyenas, lions and, most recently, the raccoon family, Sharleen Sakai has found a correlation between the size of the animals’ frontal cortex and their social nature. In her latest study, Sakai examined the digitally recreated brains of three species in the Procyonid family — the raccoon, the coatimundi and the kinkajou — and found the coatimundi had the largest frontal cortex. The frontal cortex is thought to regulate social interaction, and the coatimundi is by far the most social of the three animals, often living in bands of 20 or more. The study, funded by the National Science Foundation, is published in the research journal Brain, Behavior and Evolution. “Most neuroscience research that looks at how brains evolve has focused primarily on primates, so nobody really knows what the frontal cortex in a carnivore does,” said Sakai, professor of psychology. “These findings suggest the frontal cortex is processing social information in carnivores perhaps similar to what we’ve seen in monkeys and humans.” Sakai did the most recent study in her neuroscience lab with Bradley Arsznov, a former MSU doctoral student who’s now an assistant professor of psychology at Minnesota State University.

Her latest study was based on the findings from 45 adult Procyonid skulls acquired from university museum collections (17 coatimundis, 14 raccoons and 14 kinkajous). The researchers used computed tomography, or CT scans, and sophisticated software to digitally “fill in” the areas where the brains would have been. When they analyzed into the findings, they discovered the female coatimundi had the largest anterior cerebrum volume consisting mainly of the frontal cortex, which regulates social activity in primates. This makes sense, Sakai said, since the female coatimundi is highly social while the male coatimundi, once grown, typically lives on its own or with another male. Also known as the Brazilian aardvark, the coatimundi — or coati — is native to Central and South America. Raccoons, the most solitary of the three animals, had the smallest frontal cortex. However, raccoons had the largest posterior cerebrum, which contains the sensory area related to forepaw sensation and dexterity — and the raccoon’s forepaws are extremely dexterous and highly sensitive. The rainforest-dwelling kinkajou had the largest cerebellum and brain stem, areas that regulate motor coordination. This skill is crucial for animals like the kinkajou that live in trees. Brain size variations in this small family of carnivores appear to be related to differences in behavior including social interaction, Sakai said.

Science Daily
October 29, 2013

Original web page at Science Daily

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‘Universal’ flu vaccine effective in animals

Under the microscope, they look like simple jacks, with eight spikes jutting out of a central ball. But these protein nanoparticles are science’s latest weapon against influenza: a new breed of flu vaccine that provides better and broader protection than commercially available ones — at least in animal tests. Current flu vaccines use inactivated whole viruses and must be regularly remade to target the strains most likely to cause illness in the coming year. But the new nanoparticles would require fewer updates because they induce the production of antibodies that neutralize a wider range of flu strains. They could even protect against varieties of flu that have not yet emerged. “This is taking us on the road to a universal vaccine,” says Gary Nabel, now at the biotechnology firm Sanofi in Cambridge, Massachussetts, who led the work in his former lab at the National Institute of Allergy and Infectious Diseases in Bethesda, Maryland. The results are published on Nature’s website today.

The self-assembling nanoparticles can be made in the lab without having to grow real viruses in eggs or cell cultures, a time-consuming step of commercial vaccine preparation. “In theory, a new version could be produced quickly once a new pandemic virus had been identified, or a new seasonal variant started to circulate,” says Sarah Gilbert, a vaccine researcher at the University of Oxford, UK, who was not involved in the work. Team member Masaru Kanekiyo created the nanoparticles using haemagglutinin (HA), one of the major antigenic proteins in a flu virus’s coat, and ferritin, an iron-transporting protein that naturally forms spherical clusters. He fused these two proteins in such a way that the HA–ferritin complexes automatically assembled into a structure with a 24-piece ferritin core from which protruded eight three-piece HA spikes, mimicking the natural HA spikes in the flu virus coat. “We created an entirely new molecule that hasn’t been made before,” says Nabel. “What’s cool is that the whole thing self-assembles.”

When injected, the nanoparticles induced levels of anti-flu antibodies 34 times higher in mice and 10 times higher in ferrets compared with a traditional vaccine. Nabel thinks that this is because the HA molecules are much less densely packed on the nanoparticles than those on a real virus, and are not hidden by other coat proteins. “The immune system gets a better look at them,” he says. Although Kanekiyo built his first nanoparticles using HA from a 1999 strain of H1N1 flu, they also protected ferrets against many other H1N1 strains. These included one from 2007 that had not yet evolved when the 1999 strain was circulating, suggesting that the vaccines might protect against future strains of flu. However, Gilbert points out that it would still be necessary to have a vaccine for each of the types from H1 to H17. The antibodies induced by the nanoparticles provide such broad protection because they latch onto sites in HA that are common to different flu strains — one on the head of the protein that recognizes host cells, and another on the stem that helps the virus to penetrate cells. “Putting pressure on different parts of the virus is a good thing,” says Nabel. “That’s something you don’t see with the traditional vaccine.” The researchers now need to test their nanoparticles in humans and develop cost-effective ways of manufacturing them. They are also trying to develop vaccines against HIV and herpesvirues using the same approach — again mounting proteins onto ferritin shells. Nabel hopes that the technique will also work to make vaccines against bacterial and parasitic diseases.

Nature
June 11, 2013

Original web page at Nature

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New avian flu readily transmits in key animal model

Emerging H7N9 virus easily jumps between ferrets even though there is no evidence for human-to-human transmission. The H7N9 avian flu has not shown any signs of spreading from human to human, but its ability to spread among other mammals suggest it could yet evolve into a worse menace. A study on the novel H7N9 avian influenza that has killed 36 people in China finds that the virus is transmissible between ferrets. According to the authors, the findings suggest that H7N9 could become capable of passing from person to person — although thus far the virus has not shown any signs of doing so. The researchers, from China, Canada and the United States, inoculated six ferrets and four pigs with H7N9 isolated from a fatal human case in Shanghai. All the animals became infected. Counting humans, that makes three mammalian species that can be infected with H7N9. Tests on other species, including companion animals such as cats and dogs, could give a better idea of the host range of the virus. The H7N9 virus carries mutations that enable it to infect mammals, including humans, more easily than the related H5N1 avian flu can. There has been an unexplained lull in new cases since 7 May, but experts fear that it is only temporary.

Infections in other mammal species could provide the virus with opportunities to mutate and to adapt further. Pigs can be co-infected with avian and human flu, allowing the viruses to swap genes to create new strains, although extensive sampling in China has found no pigs harbouring H7N9. To test whether H7N9 could transmit between the ferrets by direct contact, the researchers divided six infected ferrets into pairs and placed each pair in a cage with one uninfected ferret. All the flu-free ferrets became infected. Three other flu-free ferrets were placed in cages 10 centimetres away from the infected ferrets to test for airborne transmission. One of these ferrets became infected, and another showed some H7N9 antibodies, a sign of exposure to the virus. The results are published online in Science. The relative ease of spread between ferrets is in sharp contrast to what has been observed so far in the human outbreaks that were first reported in March. It is possible that person-to-person spread occurred in three family clusters of H7N9 cases, but so far there is no firm evidence of this. Malik Peiris, a flu virologist at the University of Hong Kong and a co-author of the latest study, says that all flu viruses that spread easily between humans are also transmissible by air between ferrets. Flu infections that do not spread easily between humans, such as H5N1, do not transmit via the air between ferrets. What the latest work shows, he says, “is that this virus is closer to acquiring human-to-human transmission than other pandemic candidates out there, but not as transmissible as true seasonal flu viruses or pandemic 2009 H1N1”.

The ferrets’ flu symptoms were limited to sneezing, coughing, runny noses and mild lethargy, in contrast with the severe disease seen in humans. Although ferrets show many aspects of human flu infections, the animals are an “imperfect model” for flu virulence in humans, says Frederick Hayden, a flu virologist at the University of Virginia in Charlottesville. “It’s self-evident that the best study of human disease is the study of humans with the disease,” but the ferret studies complement these, says Peiris. He also says that autopsy data from human H7N9 cases is scarce and often reflects late-stage infection, for example, and so it does not capture the early stages of the disease. Data from infected humans, from cultured human cells and from animal experiments “all provide important and different dimensions of the questions we want to address,” Peiris says. “No one approach will give all the answers.”

Nature
June 11, 2013

Original web page at Nature

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Mercury pollution threatens arctic foxes

New scientific results show that arctic foxes accumulate dangerous levels of mercury if they live in coastal habitats and feed on prey which lives in the ocean. Researchers from the Leibniz Institute for Zoo and Wildlife Research, Moscow State University and the University of Iceland just published their discovery in the science online journal PLOS ONE. Mercury is usually transferred across the food chain, so the researchers checked which items were the main source of food and measured mercury levels in the main prey of Arctic foxes. The scientists compared three fox populations in different environments. Foxes on the small Russian Commander Island of Mednyi fed almost exclusively on sea birds, with some foxes eating seal carcasses. In Iceland, foxes living on the coast ate sea birds whereas those living inland ate non-marine birds and rodents. In all three environments different levels of mercury were present in their hair. Foxes living in coastal habitats such as Iceland and Mednyi Island exhibited high levels of mercury. What does this mean for the foxes? Using museum skin samples from the Commander Islands, the researchers could show that the foxes suffered exposure to mercury for a long time. The researchers confirmed that the source of contamination was their food, as they measured high mercury levels in the prey of foxes such as seals and sea birds.

However, the inland Arctic fox populations of Iceland had low mercury levels. Thus, living inland and eating non-marine birds and rodents instead of eating prey that feeds from the sea protected the inland foxes from mercury exposure. This may have health and conservation implications. The Mednyi Island foxes are almost an opposite example to the inland Icelandic fox population. They live on a small island with no rodents or alternative food source to seals or sea birds. They suffered a tremendous population crash and while the population is currently stable, it is very small and juvenile foxes in particular show high mortality rates. Foxes of all ages exhibit low body weight and have poor coat condition. “When going into this project we thought that an introduced pathogen would explain the poor condition of the foxes and their high mortality but after extensive screening, we did not find anything,” says Alex Greenwood, principal investigator of the study. Instead, the researchers began to suspect that something else was at play. “If pathogens were not the cause, we thought perhaps pollutants could be involved. We thought of mercury because it has been reported in high concentration in other Arctic vertebrates also in remote areas and mercury intoxication is known to increase mortality in mammals. As mercury can have negative effects on overall health, particularly in young individuals, and as we knew that Mednyi foxes were exclusively feeding on potentially contaminated sources, we wanted to see whether contamination with mercury depended on feeding ecology and hence might have been the crucial factor for the population decline on Mednyi Island,” comments Gabriele Treu, one of the lead authors of the study. As it turned out, the observed high mercury demonstrated a tight association with feeding ecology and geographical distribution of the foxes. In terms of conservation and long term population health for the entire arctic food chain of carnivores, mercury pollution must be stopped.

Science Daily
May 28, 2013

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Human disease leptospirosis identified in new species, the Banded Mongoose, in Africa

The newest public health threat in Africa, scientists have found, is coming from a previously unknown source: the banded mongoose. Leptospirosis, the disease is called. And the banded mongoose carries it. Leptospirosis is the world’s most common illness transmitted to humans by animals. It’s a two-phase disease that begins with flu-like symptoms. If untreated, it can cause meningitis, liver damage, pulmonary hemorrhage, renal failure and death. “The problem in Botswana and much of Africa is that leptospirosis may remain unidentified in animal populations but contribute to human disease, possibly misdiagnosed as other diseases such as malaria,” said disease ecologist Kathleen Alexander of Virginia Tech. With a grant from the National Science Foundation’s (NSF) Coupled Natural and Human Systems Program, Alexander and colleagues found that the banded mongoose in Botswana is infected with Leptospira interrogans, the pathogen that causes leptospirosis. Coupled Natural and Human Systems is part of NSF’s Science, Engineering and Education for Sustainability investment and is supported by NSF’s Directorates for Biological Sciences; Geosciences; and Social, Behavioral and Economic Sciences. “The transmission of infectious diseases from wildlife to humans represents a serious and growing public health risk due to increasing contact between humans and animals,” said Alan Tessier, program director in NSF’s Division of Environmental Biology. “This study identified an important new avenue for the spread of leptospirosis.” The results are published today in a paper in the journal Zoonoses and Public Health. The paper was co-authored by Alexander, Sarah Jobbins and Claire Sanderson of Virginia Tech.

The banded mongoose, although wild, lives in close proximity to humans, sharing scarce water resources and scavenging in human waste. The disease-causing pathogen it carries can pass to humans through soil or water contaminated with infected urine. Mongoose and other species are consumed as bushmeat, which may also contribute to leptospirosis exposure and infection in humans. “I was convinced that we were going to find Leptospira interrogans in some species in the ecosystem,” said Alexander. “The pathogen had not been reported previously in Botswana, with the exception of one cow more than a quarter of a century ago. “We looked at public health records dating back to 1974 and there were no records of any human cases of leptospirosis. Doctors said they were not expecting to see the disease in patients. They were not aware that the pathogen occurred in the country.” Alexander conducted a long-term study of human, wildlife and environmental health in the Chobe District of Northern Botswana, an area that includes the Chobe National Park, forest reserves and surrounding villages. “This pathogen can infect many animals, both wild and domestic, including dogs,” said Jobbins. “Banded mongoose is likely not the only species infected.” The researchers worked to understand how people, animals and the environment are connected, including the potential for diseases to move between humans and wildlife. “Diseases such as leptospirosis that have been around for a very long time are often overlooked amid the hunt for the next newly emerging disease,” Alexander said.

Leptospirosis was first described in 1886, said Jobbins, “but we still know little about its occurrence in Africa.” With the new identification of leptospirosis in Botswana, Alexander is concerned about the public health threat it may pose to the immunocompromised population there. Some 25 percent of 15- to 49-year-olds are HIV positive. “In much of Africa, people die without a cause being determined,” she said. “Leptospirosis is likely affecting human populations in this region. But without knowledge that the organism is present in the environment, overburdened public health officials are unlikely to identify clinical cases in humans, particularly if the supporting diagnostics are not easily accessible.” The researchers looked for Leptospira interrogans in archived kidneys collected from banded mongoose that had been found dead from a variety of causes. Of the sampled mongoose, 43 percent tested positive for the pathogen. “Given this high prevalence in the mongoose, we believe that Botswana possesses an as-yet-unidentified burden of human leptospirosis,” said Jobbins. “There is an urgent need to look for this disease in people who have clinical signs consistent with infection.” Because banded mongoose have an extended range across sub-Saharan Africa, the results have important implications for public health beyond Botswana. “Investigating exposure in other wildlife, and assessing what species act as carriers, is essential for improving our understanding of human, wildlife, and domestic animal risk of leptospirosis in this ecosystem,” the scientists write in their paper.

The paper also cites predictions that the region will become more arid, concentrating humans and animals around limited water supplies and increasing the potential for disease transmission. “Infectious diseases, particularly those that can be transmitted from animals, often occur where people are more vulnerable to environmental change and have less access to public health services,” said Alexander. “That’s particularly true in Africa. While we’re concerned about emerging diseases that might threaten public health–the next new pandemic–we need to be careful that we don’t drop the ball and stop pursuing important diseases like leptospirosis.” Alexander is working to identify immediate research and management actions–in particular, alerting frontline medical practitioners and public health officials to the potential for leptospirosis in humans.

Science Daily
May 28, 2013

Original web page at Science Daily

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Humans passing drug resistance to wildlife in protected areas in Africa

A team of Virginia Tech researchers has discovered that humans are passing antibiotic resistance to wildlife, especially in protected areas where numbers of humans are limited. In the case of banded mongoose in a Botswana study, multidrug resistance among study social groups, or troops, was higher in the protected area than in troops living in village areas. The study also reveals that humans and mongoose appear to be readily exchanging fecal microorganisms, increasing the potential for disease transmission. “The research identifies the coupled nature of humans, animals, and the natural environment across landscapes, even those designated as protected,” said Kathleen Alexander, an associate professor of wildlife in Virginia Tech’s College of Natural Resources and Environment. “With few new antibiotics on the horizon, wide-scale antibiotic resistance in wildlife across the environment presents a critical threat to human and animal health. As humans and animals exchange microorganisms, the threat of emerging disease also increases.”

The National Science Foundation-funded research project investigating how pathogens might move between humans and animals was published April 24, 2013 by EcoHealth. The article is co-authored by Risa Pesapane of Portsmouth, Va., then a wildlife sciences master’s student at Virginia Tech; microbiologist Monica Ponder, an assistant professor of food science and technology in Virginia Tech’s College of Agriculture and Life Sciences; and Alexander, who is the corresponding author. Alexander and Ponder are both affiliated with Virginia Tech’s Fralin Life Science Institute. Alexander, a veterinarian and researcher with the nonprofit Center for African Resources: Animals, Communities, and Land Use (CARACAL), has been conducting a long-term ecological study of banded mongoose in the region. The researchers collected fecal samples from three troops of banded mongoose living in Botswana’s Chobe National Park and three troops living in villages outside the park. “Banded mongoose forage in garbage resources and search for insects in fecal waste, including human sources found in the environment,” said Alexander. “Mongoose contact with other wildlife and humans, and broad occurrence across the landscape, makes this species an ideal candidate for evaluating microbial exchange and the potential for pathogens to be transmitted and emerge at the human-wildlife interface.”

With the exception of one mongoose troop, all study animals had some level of their range overlap with human populations. Two of the study troops had home ranges that included ecotourism facilities in the protected area, with some contact with humans and development “but at a much lower level than in the village troops,” the article reported. Fecal samples were collected from these mongoose troops living in a protected area and in surrounding villages. Human feces were collected from sewage treatment facilities, environmental spills, and bush latrines or sites of open-air defecation within mongoose home ranges. The team used Escherichia coli (E. coli), which is commonly found in the gut of humans and animals, as a model microorganism to investigate the potential for microorganisms to move between humans and wildlife. They evaluated the degree of antibiotic resistance considered an important signature of bacteria that arise from human sources. The researchers also extracted data from the local hospital to assess antibiotic resistance among patients and identify resistance patterns in the region. Like many places in Africa, antibiotics are widely available and there are few controls on the dispensing of such drugs. The project screened for nine locally available antimicrobials, including ampicillin, tetracycline, doxycycline, and streptomycin, as well as ceftiofur, a veterinary drug not available in the study area.

The researchers discovered 57 percent of banded mongoose had E. coli that was antibiotic resistant. “Resistance was identified among individuals in all sampled troops,” the article reports. The animals were most commonly resistant to ampicillin, followed by doxycyline, tetracycline, and streptomycin. But it was the prevalence of multidrug resistance that was most alarming. “There was a significant difference between troops in protected area and those outside the park, although not what you might expect,” said Alexander. One troop in the town of Kazungula, outside the protected area, had the lowest level of multidrug resistance among sampled mongoose, while a troop from the protected area living near an ecotourism facility had the highest levels. At least one sampled mongoose in this particular troop in the protected area was resistant to each of the 10 antibiotics screened in the study. As is common of mongoose that live near humans, the troop near the ecotourism facility utilized the opportunities presented by its human neighbors, setting up residence in the drain fields of the open septic tanks servicing the employee accommodations and foraging around employee living quarters, including eating food remains from dishes left outside. One interaction between the employees resulted in an unexpected finding — the kitchen staff fed raw meat waste from commercially produced chickens to mongoose.

“This may be how the mongoose developed resistance to ceftiofur,” said Alexander. The one troop living in an undisturbed region of the park was resistant to only ampicillin. “These findings reinforce the significance of human impacts to natural environments, even when human numbers are low,” said Alexander. The article reports that mongoose were resistant to the same antibiotics as humans in the region, but at a lower level. Of human fecal samples collected in the mongoose home ranges, 80.3 percent were resistant to at least one antibiotic. Of the human clinical samples screened at the local hospital, 89.9 percent of various isolated bacteria species were resistant to at least one antibiotic. “This work identifies direct support for the possibility that direct human fecal contamination of the environment is an important potential source of microbial exposure and transmission to wildlife living in these areas,” said Ponder, who was with the U.S. Centers for Disease Control and Prevention before coming to Virginia Tech. “Ecotourism developments are important for conservation and economic growth, but the associated human waste, which includes garbage as well as feces and waste water, may expose wildlife to human-associated pathogens and antibiotic resistance, ultimately increasing future threats to human health,” said Alexander.

The project was funded by a National Science Foundation (NSF) Dynamics of Coupled Natural and Human Systems award, the Morris Animal Foundation, and the WildiZe Foundation. The NSF Scholarships in Science, Technology, Engineering, and Mathematics program also provided partial financial support for Pesapane. “The impact of microbial exchange and antibiotic resistance accumulation in mongoose may extend through food webs,” the researchers conclude. “Mongoose are eaten by a large number of avian, reptile, and mammalian predators including domestic dogs. Thus, the cascading effects of exposure of wildlife species to human waste-associated microbes can impact an array of susceptible species across an ecosystem and in turn increase human exposure, coupling humans and natural systems in complicated ways.” They recommend closed sewage systems, wildlife-proofed trash receptacles, and prohibiting feeding poultry and livestock products from kitchen waste to either wildlife or domestic animals. “As we change our natural environments, these modifications can in turn impact our own health,” said Alexander. “We are working with the Botswana Ministry of Health and Ministry of Environment, Wildlife, and Tourism to minimize these impacts and develop sustainable approaches to the protection of human, wildlife, and ecosystem health.”

Pesapane said the research experience reinforced that “the issue of global sustainability and health is multifaceted, and an interdisciplinary approach is vital to achieving progress in managing health threats at this complex interface.” Pointing out the interconnectedness of human health and wellbeing and conservation of natural resources, she said, “We cannot begin to address issues of conservation without also improving quality of life in neighboring communities. “The Virginia Tech/CARACAL program under the NSF-funded program embodied this concept with expanded program focus beyond research in the Chobe region to include educational outreach and partnered efforts with the Government of Botswana to improve the quality of life for the citizens of Botswana,” she added. Pesapane, who completed her master’s in wildlife science at Virginia Tech in December 2011, is now project director of Rural System Inc. “My experience with the Alexander lab, its nonprofit affiliate CARACAL, and my education in the fish and wildlife conservation department at Virginia Tech provided a solid foundation for an inspiring career in global conservation,” she said. “Our next step,” Alexander said, “is to begin to unravel the interdependent natural and human drivers of microorganism exchange, emergence of disease, and spread of antibiotic resistance among wildlife and across environments. This will be essential to our ability to effectively manage this interface and protect the health of humans, wildlife, and environments on which we depend.”

Science Daily
May 14, 2013

Original web page at Science Daily

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Cleverly designed vaccine blocks H5 avian influenza in animal models

Until now most experimental vaccines against the highly lethal H5N1 avian influenza virus have lacked effectiveness. But a new vaccine has proven highly effective against the virus when tested in both mice and ferrets. It is also effective against the H9 subtype of avian influenza. The research is published online ahead of print in the Journal of Virology. The strength of the new vaccine is that it uses attenuated, rather than “killed” virus. (Killed viruses are broken apart with chemicals or heat, and they are used because they are safer than attenuated viruses.) Killed virus vaccines against avian influenza are injected into the bloodstream, whereas this vaccine is given via nasal spray, thus mimicking the natural infection process, stimulating a stronger immune response. The danger of current attenuated virus vaccines is that they might exchange dangerous genetic material with garden variety influenza viruses of the sort that strike annually, potentially rendering a lethal but very hard to transmit influenza virus, such as H5, easily transmissible among humans. To mitigate those dangers, the study authors, led by Daniel Perez of the University of Maryland, came up with an ingenious design. Influenza viruses carry their genetic material in eight “segments,” explains coauthor and University of Maryland colleague Troy Sutton. When viruses reassort, they exchange segments. But each segment is unique, all eight are needed, and the viruses are unfit if they contain more than eight segments.

The vaccine is based on an attenuated version of the H9 virus, with an H5 gene added into one of the H9 virus’ segments, to confer immunity to the H5 virus. Segment 8, which is composed of the so-called NS1 and NS2 genes, was split apart, and the NS2 gene was moved into segment 2, adjacent to the polymerase gene, which copies the virus’ genetic material during replication. Placing NS2 next to the polymerase gene slowed its function, interfering with the virus’ replication. That makes the vaccine safer. The next step was to engineer the H5 gene into the vaccine. It was inserted into segment 8, where the NS2 gene had been. Another aspect of the new vaccine’s design makes it safer still, by rendering successful reassortment less likely. Both NS1 and NS2 are needed for viral replication. Since the two genes are now separated into different segments, any reassortment will have to include both segments, instead of just segment 8, in order for a reassortant virus to be viable. This greatly reduced the probability of successful reassortment. The World Health Organization (WHO) recognizes avian influenza subtypes H5, H7, and H9 as potential pandemic viruses, because they all have in rare instances infected humans, and because they circulate in wild birds. Single reassortants could be sufficient to breach the species barrier, and since they do not circulate among us, we lack any immunity. Moreover, H5 is unusually lethal, having killed roughly half of those few it is confirmed to have infected.

Science Daily
April 16, 2013

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Work resumes on lethal flu strains

An international group of scientists this week ended a year-long moratorium on controversial work to engineer potentially deadly strains of the H5N1 avian flu virus in the lab. Researchers agreed to temporarily halt the work in January 2012, after a fierce row erupted over whether it was safe to publish two papers reporting that the introduction of a handful of mutations enabled the H5N1 virus to spread efficiently between ferrets, a model of flu in mammals (see Nature http://doi.org/fxv55r; 2012). Both papers were eventually published, one in Nature and one in Science. Now, in a letter simultaneously published on 23 January by Nature and Science, the 40 scientists involved say that the moratorium has served its purpose: allowing time for authorities to review the conditions under which the research could be safely conducted and for scientists to explain the public-health benefits of the work. Scientists who now have official approval in their countries to conduct such research “have a public-health responsibility to resume this important work”, the letter states, “because the risk exists in nature that an H5N1 virus capable of transmission in mammals may emerge”.

The move follows a large international workshop convened on 17–18 December by the US National Institutes of Health in Bethesda, Maryland, to discuss ‘gain-of-function research’ — that intended to increase the transmissibility, host range or virulence — in H5N1 viruses, and the development of US rules for stricter oversight of research in this area. The proposed rules require an assessment of, for example, whether the scientific aims of such studies could be addressed using alternative, less-risky approaches, and whether biosafety and biosecurity risks can be adequately mitigated. They are expected to enter into force soon, allowing scientists working in the United States or on US-funded grants to restart such research. The groups that published the original research have outlined a suite of possible follow-up experiments, including a search for other combinations of mutations that would allow H5N1 to transmit between mammals — which could answer basic-science questions and, they argue, aid efforts to watch for dangerous mutations in the wild. The researchers also suggest extending the studies in ferrets to other mammals, such as guinea pigs, because further evidence of transmission within mammalian species would increase confidence that the mutated virus would transmit between humans. But the scientific community remains divided on whether the practical benefits of the research outweigh the risks of an accidental or deliberate release of a lab-created flu strain. Ian Lipkin, a specialist on emerging infectious diseases at Columbia University in New York, believes that the risks are high and, worse, that such research may end up being done in labs with insufficient biosafety standards.

The World Health Organization (WHO) posted general biosafety guidelines for such work on its website last July (go.nature.com/4z4yzg), but Lipkin says such guidelines need to be extended and given more teeth before work restarts. He suggests that this could be done by including them in the WHO’s international legally binding treaty on global threats to health — the 2005 International Health Regulations. Ron Fouchier at Erasmus Medical Centre in Rotterdam, the Netherlands, who led the research behind last year’s Science paper, disagrees. He says that national and institutional procedures have long proved adequate. “If we have to wait until all national governments in the world agree on terms and conditions, we can wait for years if not forever,” he says. “That is unacceptable.” But even some who support the lifting of the moratorium have misgivings about the future. Ilaria Capua, a flu researcher at the Veterinary Public Health Institute in Legnaro, Italy, who signed the letter, says that she is less concerned about current work, which is limited to a handful of labs with high biosafety standards, than about the risk of proliferation of such research in the longer term. “This is not a decision for scientists,” she says, “it’s a decision for policy-makers; do we want to continue to invest public funds in this type of work?”

Nature
February 5, 2013

Original web page at Nature

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Novel polyomavirus associated with brain tumors in free-ranging raccoons, western United States

Tumors of any type are exceedingly rare in raccoons. High-grade brain tumors, consistently located in the frontal lobes and olfactory tracts, were detected in 10 raccoons during March 2010–May 2012 in California and Oregon, suggesting an emerging, infectious origin. We have identified a candidate etiologic agent, dubbed raccoon polyomavirus, that was present in the tumor tissue of all affected animals but not in tissues from 20 unaffected animals. Southern blot hybridization and rolling circle amplification showed the episomal viral genome in the tumors. The multifunctional nuclear protein large T-antigen was detectable by immunohistochemical analyses in a subset of neoplastic cells. Raccoon polyomavirus may contribute to the development of malignant brain tumors of raccoons. The American Cancer Society estimates that infectious pathogens are associated with up to 20% of all human cancers worldwide. Among oncogenic viruses are those in the Polyomaviridae family, whose members infect an array of vertebrate species, including birds, humans, nonhuman primates, bovids, rodents, and sea lions.

Infection in mammals typically results in persistent asymptomatic infection. However, natural disease studies of human infection and experimental disease studies suggest that a potential outcome of some polyomavirus (PyV) infections is tumor formation. Experimental evidence that PyVs are tumorigenic is 50 years old and not debated; PyV-induced tumorigenesis in laboratory animals, by simian virus 40 (SV40) or by multiple human PyVs, such as JC virus (JCV), is used extensively as a cell transformation model. JCV, for example, induces brain tumors when intracerebrally inoculated in experimental animals. Furthermore, transgenic mice harboring the viral-encoded large T-antigen (LT-Ag) alone develop tumors of neuroectodermal origin, including malignant peripheral nerve sheath tumors (MPNSTs) and glioblastomas. Evidence that PyVs induce tumors after natural infection is accumulating but more controversial. Studies reliant on molecular detection of tumor-associated virus in isolation, however extensive, are inconclusive because association between PyVs and naturally occurring neoplasms varies and because PyV infections are highly prevalent, yet tumor formation is rare. Thus, although PyV-induced oncogenesis in laboratory animals has been a prolific model for the study of the cell cycle and cell transformation, natural infections rarely result in tumor formation, so the steps in cell transformation after natural infection are being revealed more slowly. Recent advances have been made by an accumulation of studies on Merkel cell polyomavirus (MCPyV), which is highly associated and integrated in most Merkel cell carcinomas. However, several unanswered questions relating to persistence, transmission, and transformation remain.

Most veterinary diagnostic laboratories receive large numbers of raccoon (Procyon lotor) carcasses for diagnosis, yet tumors of any type are rarely reported. In northern California and southern Oregon, we diagnosed 10 cases of olfactory tract/frontal lobe brain tumors in free-ranging raccoons during March 2010–May 2012. During the same period, no other raccoon tumors were reported in diagnostic laboratories across the United States and Canada. The clustering of cases and association of the tumors with the olfactory pathways suggested an infectious cause with a distinct route of transmission and tropism. We characterized from these tumors a candidate etiologic agent, raccoon polyomavirus (RacPyV).

Emerging Infectious Diseases
January 22, 2013

Original web page at Emerging Infectious Diseases

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Italian wolves prefer pork to venison

Scientists from Durham University, UK, in collaboration with the University of Sassari in Italy, found that the diet of wolves was consistently dominated by the consumption of wild boar which accounted for about two thirds of total prey biomass, with roe deer accounting for around a third. The study analysed the remains of prey items in almost 2000 samples of wolf dung over a nine year period and revealed that an increase in roe deer in the wolf diet only occurred in years when boar densities were very low. In years of high roe deer densities, the wolves still preferred to catch wild boar. The results are published in the journal PLOS ONE. The research team related the prey remains in wolf dung to the availability of possible prey in part of Tuscany, Italy — an area recently colonised by wolves. The findings have implications for wildlife conservation as the impact of changing predator numbers on prey species is important for managing populations of both predators and prey. Lead author, Miranda Davis, from the School of Biological and Biomedical Sciences at Durham University, said: “Our research demonstrates a consistent selection for wild boar among wolves in the study area, which could affect other prey species such as roe deer.” “Intriguingly, in other parts of Europe where red deer are also available, wolves appear to prefer this prey to wild boar, suggesting that they discriminate between different types of venison.”

In Europe, the wolf (Canis lupis) is recovering from centuries of persecution and the expansion of wolf populations has the potential to change the ecology of communities of ungulates (hooved animals) by exposing them to natural predation by wolves, according to the researchers. The preference for boar is in contrast to other areas of Europe where wolves often avoid boar as prey. One factor may be the relatively smaller size of Mediterranean boar, making them less dangerous to wolves in Mediterranean regions, compared to the larger-sized boar that roam other parts of Europe. Co-author, Dr Stephen Willis, from the School of Biological and Biomedical Sciences at Durham University, said: “Wolves were hunted to extinction in the UK, probably by the end of the 17th century. Our findings from Italy suggest that if they were reintroduced into an area with a healthy ungulate population their impact on livestock could be minimal.” Tuscany’s woodlands support populations of both roe deer and wild boar, and are also grazed by sheep, goats and cattle; however, wild boar and roe deer made up over 95 per cent of wolf diet in the study area, with very little evidence of livestock predation. The scientists identified prey items from fragments of bones and hair in the wolf dung collected in the region. The prey categories included wild boar, roe deer, red deer, hare, small rodents, goats, sheep and cattle.

For more than five years of the study, the percentage of wolf diet made up of wild boar was more than twice that of roe deer. Other prey represented only a very small proportion of the diet. The researchers believe that further dietary studies are essential for understanding the true impact of wolves on European wildlife over time. Co-author, Dr Phil Stephens, from the School of Biological and Biomedical Sciences at Durham University added: “Wolves and brown bears are gradually returning to their former strongholds in Europe. Understanding the needs of these species, as well as their potential impacts, is going to be fundamental to managing that welcome return.” The project was part-funded by a Durham University Doctoral Fellowship and the Regional Government of Tuscany and the Province of Arezzo also provided logistical support throughout the study.

Science Daily
January 22, 2013

Original web page at Science Daily

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Captive animals show signs of boredom

Wondering if your caged hamster gets bored? It’s highly likely if the critter has nothing to do all day. Those are the findings of University of Guelph researchers in the first research study to empirically demonstrate boredom in confined animals. The study appears today in PLOS ONE, published by the Public Library of Science. The study’s authors hope the results encourage the development of better housing systems for captive animals. “Ideas about how to assess animal boredom scientifically have been raised before, but this is really the first time that anyone’s done it,” said Rebecca Meagher, a U of G postdoctoral researcher and the study’s lead author. It’s well-established that living in unchanging, inescapable environments induces boredom in humans, including prisoners who report that they are highly motivated to seek stimulation. “But we cannot rely on verbal self-reports from non-humans, so motivation to obtain general stimulation must form the basis of any objective measure of boredom in animals,” said Prof. Georgia Mason, who holds the Canada Research Chair in animal welfare in Guelph’s Department of Animal and Poultry Science.

The researchers presented captive mink with stimuli ranging from appealing treats to neutral objects to undesirable things, such as leather gloves used to catch the animals. Half of the animals in the study lived in small, bare cages. The other half lived in large “enriched” cages that were enhanced with water for wading, passageways for running, objects to chew and towers to climb. The researchers found that animals in confined, empty spaces avidly seek stimulation, which is consistent with boredom. Those mink approached stimuli — even normally frightening objects — three times more quickly and investigated them for longer. These animals also ate more treats, even when given as much food as mink in enriched environments. When they were not being tested, mink in empty cages spent much of their waking time lying down and idle. Among them, those that spent the most time awake but motionless showed the keenest interest in stimuli. “We don’t know whether mink or other animals truly feel bored in the same way that humans do,” Meagher said. “We can’t measure that type of subjective experience. But we can see that, when they have little to do, then just like many bored humans, they may look listless, and, if given the chance, eagerly seek any form of stimulation.”

Guelph neuroscientist and psychology professor Mark Fenske, an expert in human cognition and emotion and recent co-author of a comprehensive review of boredom research, said the study is an important addition to the literature. “Surprisingly little is known about boredom, even though it is associated with significant adverse consequences for health and well-being,” he said. “Being able to now study boredom in non-human animals is an important step in our efforts to understand its causes and effects and find ways to alleviate boredom-related problems across species.” Meagher and Mason hope the findings will prompt further research, including looking at whether intelligent animals such as primates and parrots are particularly prone to boredom in captivity, and why under-stimulation causes problems.

Science Daily
November 27, 2012

Original web page at Science Daily

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Mycoplasmosis in ferrets

Report of an outbreak of severe respiratory disease associated with a novel Mycoplasma species in ferrets. During 2009–2012, a respiratory disease characterized by nonproductive coughing affected ≈8,000 ferrets, 6–8 weeks of age, which had been imported from a breeding facility in Canada. Almost 95% became ill, but almost none died. Treatments temporarily decreased all clinical signs except cough. Postmortem examinations of euthanized ferrets revealed bronchointerstitial pneumonia with prominent hyperplasia of bronchiole-associated lymphoid tissue. Immunohistochemical analysis with polyclonal antibody against Mycoplasma bovis demonstrated intense staining along the bronchiolar brush border. Bronchoalveolar lavage samples from 12 affected ferrets yielded fast-growing, glucose-fermenting mycoplasmas. Nucleic acid sequence analysis of PCR-derived amplicons from portions of the 16S rDNA and RNA polymerase B genes failed to identify the mycoplasmas but showed that they were most similar to M. molare and M. lagogenitalium. These findings indicate a causal association between the novel Mycoplasma species and the newly recognized pulmonary disease.

Emerging Infectious Diseases
November 13, 2012

Original web page at Emerging Infectious Diseases

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Evolution mostly driven by physical strength, not brains

The most common measure of intelligence in animals, brain size relative to body size, may not be as dependent on evolutionary selection on the brain as previously thought, according to a new analysis by scientists. Brain size relative to body size has been used by generations of scientists to predict an animal’s intelligence. For example, although the human brain is not the largest in the animal kingdom in terms of volume or mass, it is exceptionally large considering our moderate body mass. Now, a study by a team of scientists at UCL, the University of Konstanz, and the Max Planck Institute of Ornithology has found that the relationship between the two traits is driven by different evolutionary mechanisms in different animals. Crucially, researchers have found that the most significant factor in determining relative brain size is often evolutionary pressure on body size, and not brain size. For example, the evolutionary history of bats reveals they decreased body size much faster than brain size, leading to an increase in relative brain size. As a result, small bats were able to evolve improved flying manoeuvrability while maintaining the brainpower to handle foraging in cluttered environments. This shows that relative brain size can not be used unequivocally as evidence of selection for intelligence. The study is published today in the Proceedings of the National Academy of Sciences.

Dr Jeroen Smaers (UCL Anthropology and UCL Genetics, Evolution & Environment), lead author of the study said: “When using brain size relative to body size as a measure of intelligence, the assumption has always been that this measure is primarily driven by changes in brain size. It now appears that the relationship between changes in brain and body size in animals is more complex than has long been assumed. “Changes in body size often occur independently of changes in brain size and vice versa. Moreover, the nature of these independent changes in brain and body size, are different in different groups of animals.” Researchers at UCL gathered data on brain and body mass for hundreds of modern and extinct bats, carnivores, and primates. They then charted brain and body size evolution over time for each species. Across millions of years, most animals increased body size faster than brain size, with the exception of bats. In primate lineages decreases in brain size marginally outpaced those in body size. Carnivore evolution has taken yet a different course, with changes generally more strongly associated with body size rather than selection on brain size and cognition. Given such differences, the authors believe that the predominant interpretation of relative brain size as the consequence of selection on intelligence inherently masks the often more significant influence of selection on body size.

Science Daily
October 30, 2012

Original web page at Science Daily

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Urban coyotes never stray: New study finds 100 percent monogamy

Coyotes living in cities don’t ever stray from their mates, and stay with each other till death do them part, according to a new study. The finding sheds light on why the North American cousin of the dog and wolf, which is originally native to deserts and plains, is thriving today in urban areas. Scientists with Ohio State University who genetically sampled 236 coyotes in the Chicago area over a six-year period found no evidence of polygamy — of the animals having more than one mate — nor of one mate ever leaving another while the other was still alive. This was even though the coyotes exist in high population densities and have plenty of food to eat, which are conditions that often lead other dog family members, such as some fox species, to stray from their normal monogamy. “I was surprised we didn’t find any cheating going on,” said study co-author Stan Gehrt, a wildlife ecologist with Ohio State’s School of Environment and Natural Resources. “Even with all the opportunities for the coyotes to philander, they really don’t. “In contrast to studies of other presumably monogamous species that were later found to be cheating, such as arctic foxes and mountain bluebirds, we found incredible loyalty to partners in the study population.” The study appears in a recent issue of The Journal of Mammalogy.

The loyalty of coyotes to their mates may be a key to their success in urban areas, according to Gehrt. Not only does a female coyote have the natural ability to produce large litters of young during times of abundance, such as when living in food-rich cities, she has a faithful partner to help raise them all. “If the female were to try to raise those large litters by herself, she wouldn’t be able to do it,” said Gehrt, who holds appointments with the university’s Ohio Agricultural Research and Development Center and Ohio State University Extension. “But the male spends just as much time helping to raise those pups as the female does.” Unlike the males of polygamous species, a male coyote “knows that every one of those pups is his offspring” and has a clear genetic stake in helping them survive, Gehrt said. The research was done in Cook, Kane, DuPage and McHenry counties in northeast Illinois. All are in greater Chicago, which is home to about 9 million people and is the third-largest metropolitan area in the U.S. It’s also home to an estimated 1,000 to 2,000 coyotes. Gehrt has previously said he “couldn’t find an area in Chicago where there weren’t coyotes.” “You’ve got lots of coyotes in this landscape,” said senior author Cecilia Hennessy, who conducted the study as a master’s degree advisee of Gehrt and is now a doctoral student at Purdue University in Indiana. “You’ve got territories that abut each other. And coyotes can make long-distance forays. So you’d think, based on previous investigations of dog behavior, that cheating would be likely. “But to find nothing, absolutely nothing, no evidence whatsoever of anything that wasn’t monogamy, I was very surprised by that,” she said.

The finding came through a wider study of Chicago-area coyotes that Gehrt has led since 2000. As the largest study ever on urban coyotes, it’s a long-term effort to understand the animals’ population ecology, how they adapt to urban life and how to reduce their conflicts with people. “A powerful part of the new paper is that we have long-term field work, behavior observations, to accompany Cecilia’s genetic work,” Gehrt said. “So many genetic studies only analyze samples but know very little about their subjects, whereas we follow these individuals nearly every day and often to the completion of their lives. It’s a nice mesh of lab and field work.” The scientists used live traps — either padded foothold traps or non-choking neck snares — to catch the coyotes for the study, although pups were simply dug from their dens and held by hand. Small blood and tissue samples were taken from all the animals. The adults, which were anesthetized, also were fitted with radio-collars for tracking their movements and ranges. Afterward, all the coyotes were released where they were caught. Later, Hennessy, who previously was a plant genetics technician and biology major at the University of Cincinnati, used genetic techniques in the lab to test the animals’ DNA and determine their family trees.

Coyotes maintain monogamy through long-term pair bonding, a term meaning an animal stays with the same mate for more than one breeding season, and sometimes for many. A male coyote, for his part, practices diligent mate guarding — keeping other males away from the female. During estrus, which is the time when the female can become pregnant, the pair “will spend all their time together — running, finding food, marking their territory. They’ll always be right at each other’s side.” “We’ve been able to follow some of these alpha pairs through time, and we’ve had some of them stay together for up to 10 years,” Gehrt said. “They separate only upon the death of one of the individuals, so they truly adhere to that philosophy, ‘Till death do us part,’ ” Hennessy said.

Science Daily
October 16, 2012

Original web page at Science Daily

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Tigers take the night shift to coexist with people

Tigers aren’t known for being accommodating, but a new study in the Proceedings of the National Academy of Sciences indicates that the carnivores in Nepal are taking the night shift to better coexist with humans. The revelation that tigers and people are sharing exactly the same space — the same roads and trails — of Chitwan National Park flies in the face of long-held convictions in conservation circles. It also underscores how successful conservation efforts need sciences that takes into account both nature and humans. “As our planet becomes more crowded, we need to find creative solutions that consider both human and natural systems,” said Jianguo “Jack” Liu, the director of the Center for Systems Integration and Sustainability at Michigan State University. “Sustainability can be achieved if we have a good understanding of the complicated connections between both worlds. We’ve found something very interesting is happening in Nepal that holds promise for both humans and nature to thrive.” Conventional conservation wisdom is that tigers need plenty of people-free space, which often leads to people being relocated or their access to resources compromised to make way for tigers. Neil Carter, MSU doctoral student and one of the paper’s co-authors, spent two seasons setting motion-detecting camera traps. His analysis of the images shows that people and tigers are walking the same paths, albeit at different times. Tigers typically move around at all times of the day and night, monitoring their territory, mating and hunting. But in the study area, the tigers had become creatures of the night. People in Nepal generally avoid the forests at night. Essentially, quitting time for people signals starting time for Chitwan’s tigers.

“It’s a very fundamental conflict over resources,” Carter said. “Tigers need resources, people need the same resources. If we operate under the traditional wisdom that tigers only can survive with space dedicated solely for them, there would always be conflict. If your priority is people, tigers lose out. If your priority is tigers, people lose out.” In Chitwan, tigers seem to be adapting to make it work, he added. “There appears to be a middle ground where you might actually be able to protect the species at high densities and give people access to forest goods they need to live,” Carter said. “If that’s the case, then this can happen in other places, and the future of tigers is much brighter than it would be otherwise.” Additional co-authors of the paper include Binoj Shresthaof the Institute for Social and Environmental Research in Nepal, Jhamak Karkiof Nepal’s Department of National Parks and Wildlife Conservation and Narendra Man Babu Pradhan of the World Wildlife Fund in Nepal.

Science Daily
September 18, 2012

Original web page at Science Daily

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Flu is transmitted before symptoms appear, study in ferrets suggests

Research at Imperial College London examining influenza transmission in ferrets suggests that the virus can be passed on before the appearance of symptoms. If the finding applies to humans, it means that people pass on flu to others before they know they’re infected, making it very difficult to contain epidemics. Knowing if people are infectious before they have symptoms is important to help authorities plan for an epidemic, but is has been difficult to establish this from data collected during outbreaks. Previous research using mathematical models estimated that most flu transmission occurs after the onset of symptoms, but some happens earlier. The new study, published in the open access journal PLoS ONE, is the first to investigate this question experimentally in an animal model. Ferrets are commonly used in flu research because they are susceptible to the same virus strains and show similar symptoms to humans.

Ferrets with flu were put in contact with uninfected ferrets for short periods at different stages after infection. Transmission occurred before the first symptom, fever, appeared, both when the ferrets were in the same cage and when they were in adjacent cages. Professor Wendy Barclay, the study’s lead author from the Department of Medicine at Imperial College London, said: “This result has important implications for pandemic planning strategies. It means that the spread of flu is very difficult to control, even with self-diagnosis and measures such as temperature screens at airports. It also means that doctors and nurses who don’t get the flu jab are putting their patients at risk because they might pass on an infection when they don’t know they’re infected.” The flu strain used in the study was from the 2009 swine flu pandemic, which killed almost 300,000 people worldwide. The researchers found that ferrets were able to pass on flu to others just 24 hours after becoming infected themselves. The animals did not suffer from fever until 45 hours after infection and began sneezing after 48 hours. The results are consistent with earlier studies which found that sneezing is not necessary to transmit flu — droplets of virus are expelled into the air during normal breathing. In the late stages of infection, after five or six days, flu was transmitted much less frequently, suggesting that people can return to work or school soon after symptoms subside with little risk of passing flu on to others.

Science Daily
September 18, 2012

Original web page at Science Daily

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Meat-eating animals lack genes involved in detecting sweet flavours

Sea mammals, spotted hyenas and other carnivores have all shed a working copy of a gene that encodes a ‘taste receptor’ that senses sugars, finds a study published this week in the Proceedings of the National Academy of Sciences. An animal with a diet devoid of vegetables may have little need to detect sugars, says Gary Beauchamp, director of the Monell Chemical Senses Center in Philadelphia, Pennsylvania, and the lead author of the study. He sees parallels with cave-dwelling fish that have lost their sense of sight. Most mammals, including humans, are equipped with taste receptors that detect salty, sour, sweet, bitter and savoury foods. But past studies suggest that some animals lack certain taste receptors. Felines such as house cats, tigers and cheetahs do not favour sugar water over plain water, for example, and they all possess an identical mutation in a gene called Tas1r2 that renders the sweet-taste receptor inactive. To see whether other carnivores also lack sweet receptors, Beauchamp and his team collected DNA from 12 members of the order Carnivora, including spotted hyenas, a cat-like creature from Madagascar called a fossa, a civet called a banded linsang and several species of sea mammal. Seven of the species contained a broken copy of the gene encoding the sugar taste receptor, but the exact mutations often differed among them. For instance, fur seals and sea lions share many mutations in Tas1r2, but the more distantly related Pacific harbour seal lost its sense of sweetness through different mutations in that gene. The species of land mammals that the researchers examined each contained unique Tas1r2 mutations.

That the mutations are not identical across species suggests that carnivores have independently lost their ability to detect sugars, an example of convergent evolution. Plants are the major source of dietary sugars, so it makes sense that animals that consume mainly meat or fish could live without a working sugar taste receptor. There is no evidence, however, that carnivores benefit from losing the ability to sense sugars, and some animals such as the insect-eating aardwolf, which is closely related to hyenas, and the omnivorous spectacled bear have working copies of the genes that encode the sweet taste receptors.

Sweetness isn’t the only taste that meat-eaters do not experience. Beauchamp and his team found that some of the carnivores they studied have also lost their ability to taste other flavours. Bottlenose dolphins and sea lions lack working copies of the gene encoding receptors for tasting savoury flavours (also called umami, produced by amino acids), and dolphins seem also to have shed a receptor that senses bitter compounds . Beauchamp suggests that taste may not have a very important role in what these creatures eat — sea lions and dolphins have few taste buds and tend to swallow things whole. Peng Shi, a geneticist at the Kunming Institute of Zoology in China, was surprised to see that so many mammals have jetisoned their sweet receptors. Scientists have found little diversity in sweet receptor genes, among animals with working copies, underscoring their importance.

Nature
April 3, 2012

Original web page at Nature

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Hidden poaching takes a toll on Scandinavian wolves

Wolves have been disappearing mysteriously in Sweden. Between 1999 and 2009, 18 of the animals—or about 17% of the individuals that researchers have actively followed—have gone missing; the global positioning system (GPS) collars used to track them suddenly blinked off, and the wolves never reemerged. Researchers suspected poaching, but it’s been hard to determine how much of a toll such clandestine kills have taken. Now, by using a new mathematical analysis, scientists have estimated that poaching accounts for half the deaths of Scandinavian wolves, potentially stymieing the rare predator’s recovery. As recently as the 1970s, not a single wolf lived in Norway or Sweden, says Guillaume Chapron, a conservation scientist at the Swedish University of Agricultural Sciences in Riddarhyttan and a co-author of the new study. DNA evidence has shown that those carnivores living in the region today descend from a single male-female pair that made the treacherous trek from Finland in the early 1980s and a second male that arrived in 1991. Packs have grown steadily from those three founders; in 2009, Sweden and Norway were home to 263 wolves.

To keep an eye on their numbers, Scandinavian researchers fitted 104 wolves with GPS collars between 1999 and 2009. When a GPS blip goes dead, conservationists with the Scandinavian Wolf Project SKANDULV go looking. Some teams circle wolf territories in helicopters, whereas others set out on skis or snowmobiles to follow tracks and locate scat for DNA testing. If these extensive searches turn up nothing, as happened with 18 wolves that disappeared over the past 10 years, Chapron and his colleagues suspect foul play. “We cannot find any other mortality cause that would destroy the wolf and the radio-tracking collar other than poaching,” he says. But bodies still haven’t turned up for any of the lost wolves. Chapron suspects that poachers disposed of their remains and the GPS collars to cover up the crimes. So instead, the researchers turned to ecology to show the extent of poaching in Scandinavia. Chapron and his colleagues projected how fast the Scandinavian wolf packs should have grown between 1999 and 2009. Had wolves died only from known causes—illnesses, speeding cars, and a few cases of confirmed poaching—numbers would have grown from 74 animals to nearly 700. But in 2009, researchers counted fewer than 300 wolves in Sweden and Norway, the team reports online today in the Proceedings of the Royal Society B.

Poachers didn’t kill 400 wolves directly but took out an unknown number of males and females that would’ve otherwise been able to breed and multiply. “You cannot really explain the population counts,” Chapron says. “You need an extra source of mortality.” In other words, hidden poaching. Chapron says that in Scandinavia, much of the conflict between wolves and people arises from an unlikely source: moose hunts. Hunting dogs are a big part of these outings, a national pastime in Sweden. But wolves often maul or kill dogs when they get too close, and that gets hunters angry, he says. Regardless of the motive, illegal kills account for about 50% of total wolf deaths in Scandinavia, Chapron and colleagues estimate. In two-thirds of those cases, poachers seem to be killing and ditching the evidence without anyone knowing. Such “cryptic poaching” takes a whopping toll on the population, and it’s one that has gone unrecognized until now. The difficulty in estimating poaching’s toll is that people rarely fess up, even in regions lacking Sweden’s strict law enforcement, says Julia Jones, a conservation scientist at Bangor University in the United Kingdom, who was not involved in the study. Adopting psychological tools drawn from interview-based studies of prostitutes and drug addicts, she investigates the illegal hunting of lemurs in Madagascar and poaching of other endangered animals. But Chapron’s team went the other direction, one that she considers solid. “They’re using purely ecological and biological data … to infer something about a social behavior.”

ScienceNow
September 6, 2011

Original web page at ScienceNow

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The smell of a meat-eater

A chemical found in the urine of carnivores such as bobcats could shed light on the control of instinctive behaviour. If you are a small animal, it is useful to know whether there is anything around that might want to eat you. Stephen Liberles from Harvard Medical School in Cambridge, Massachusetts, and his colleagues have analysed urine samples from a variety of zoo inhabitants, including lions and bears, and discovered how rodents can use smell to do just that. In a research published today in the Proceedings of the National Academy of Science, the team identifies a chemical found in high concentrations in the urine of carnivores that makes mice and rats run for cover. Chemicals have already been identified that allow prey to recognize a known predator. But this is the first example of a generic clue that allows an animal to detect any potential predator, irrespective of whether the two species have ever come into contact. The researchers started by analysing an engimatic group of olfactory receptors discovered in 2001 called trace amine-associated receptors (TAARs). They are found in most vertebrates, in varying numbers. Mice, for example, have 15, rats 17 and humans have just 6. Very little is known about what chemicals bind to them. “A giraffe had to be trained to urinate in a cup.”

Liberles and his colleagues found that one member of the receptor family, TAAR4, is strongly activated by bobcat urine, which is sold online and used by gardeners to keep rodents and rabbits away. They managed to extract the molecule responsible for activating the receptor, called 2-phenylethylamine. They then wondered whether the molecule was specific to the bobcat. But the urine from other animals cannot always be bought as easily. “Also, commercial products may be contaminated, whereas we wanted to be sure we were studying only natural substances,” says David Ferrero, a graduate student in Liberles’s lab and first author of the study. So the researchers collected urine samples from a range of sources, including zoos in New England and South Dakota. Their collection covered 38 species from predators such as lions, snow leopards and servals to herbivores including cows, giraffes and zebra. They also tested humans, cats and various rodents.

The operation was not trivial. A giraffe had to be trained to urinate in a cup, and Ferrero had a nose-to-nose encounter with an uncooperative jaguar when the animal jumped against the bars as he approached its cage. Carnivores had by far the greatest concentration of 2-phenylethylamine in their urine, with the highest levels in lion, serval and tiger. Levels in the herbivores’ urine were up to 3,000 times lower. The chemical might be a by-product of digesting meat proteins, although the researchers have yet to confirm this idea. Liberles and his team double-checked the role of 2-phenylethylamine by placing a few drops of it – on its own, or within lion urine – in a cage. They found that mice and rats stayed away from that part of the cage. But when they used an enzyme to remove the chemical from lion urine, the drops no longer caused any reaction. “The role of TAAR receptors is still a bit of a mystery,” says Anna Menini, a physiologist at the International School for Advanced Studies in Trieste, Italy, and president-elect of the European Chemoreception Research Organization in Paris. “Here we have the first convincing evidence that they might control instinctive behaviour.”

She adds that the study questions a dogma in olfactory studies: that the olfactory receptors that trigger instinctive responses are found only in the vomeronasal organ, a part of the olfactory system that humans have lost. TAARs are in the olfactory epithelium — specialized tissue on the roof of the nasal cavity — which humans have, although they do not have an active gene for TAAR4 itself. The researchers are still missing the smoking gun for proving that TAAR4 directly controls the animal’s behaviour: a mouse in which this receptor has been knocked out should be fearless when faced with a carnivore’s urine. Liberles says he is working on this, as well as studying what brain circuits are activated by the receptor. “That is the big black box in neuroscience” he says. “We know a lot about perception and we can observe behaviour, but we need to find the circuits in the brain that bridge the two. TAAR4 offers a way to do that.”

Nature
July 12, 2011

Original web page at Nature

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Larger female hyenas produce more offspring

When it comes to producing more offspring, larger female hyenas outdo their smaller counterparts. A new study by Michigan State University researchers, which appears in Proceedings of the Royal Society, revealed this as well as defined a new way to measure spotted hyenas’ size. “This is the first study of its kind that provides an estimate of lifetime selection on a large carnivore,” said MSU graduate student Eli Swanson, who published the paper with MSU faculty members Ian Dworkin and Kay Holekamp, all members of the BEACON Center for the Study of Evolution in Action. “In short, we were able to document that larger female hyenas have more cubs over their lifetime than do smaller females as well as develop a novel approach for estimating body size.” Size can be one of the most important traits affecting an animal’s life. It influences eating, getting eaten, speed and agility, and attractiveness to potential mates. However, overall height and weight measurements may not capture differences in more specific traits like leg length that might be more important in survival.

To identify the most-important traits, researchers sedated hyenas in Kenya and took 13 measurements on each subject, including total body length, skull size and leg length. They found that while overall size didn’t affect reproductive success, some clusters of traits did. They also learned that the length of the lower leg, the height at the shoulder and body length were all individually associated with more reproductive success. “Our results highlight the importance of choosing appropriate measures when estimating animal body size,” Swanson said. “They also suggest researchers should take caution in interpreting selection on size-related traits as selection on size itself.” Spotted hyenas are particularly interesting because females are larger than males, which is extremely unusual among mammals. In most mammals, the size difference is easy to explain. Larger males get more food and attract more females, but females are faced with a tradeoff between their own body size and the energy needed for pregnancy and lactation. As of yet, the size difference between the sexes is still unsolved. However, researchers have been able to shed light on the reasons for the large females’ success. They found that larger females reproduce more often and live longer after beginning to reproduce, when compared to smaller females. Estimating fitness — or success at surviving and reproducing — can be difficult with spotted hyenas, which can live at least 19 years in the wild. Since Holekamp’s field study of spotted hyenas has been ongoing for more than 20 years, the researchers were able to count the number of surviving offspring produced by a female in her lifetime, as well as the length of her total reproductive lifespan.

Science Daily
April 5, 2011

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The grey wolf: symbol of conservation or dangerous predator?

Robert Millage had heard the howls of wolves in the area the day before, so he knew where to wait. As the sun rose, and the howls rang out again, he blew on his hunter’s call, emitting a sound like a coyote in distress. Fifteen minutes later, a two-year-old she-wolf strode into the clearing. “You don’t have a lot of time to think,” says Millage, an estate agent in Kamiah, Idaho. He raised his rifle and shot. “She went down in her tracks,” he says. Millage’s hunting trip was in September 2009, a few months after most of the west’s wolves were taken off the US government’s list of endangered species. That decision was taken within the framework of the Endangered Species Act, but was overturned by a federal judge. Now, lawmakers are trying to delist the wolves again by legislative fiat — sidestepping both the act and, conservation biologists fear, the science. The attempts to remove the wolf a second time come in response to an August 2010 federal court ruling that stated that Northern Rocky Mountain wolves should go back on the endangered species list. The US Fish and Wildlife Service had delisted wolves in all states except Wyoming, which had promised to allow its residents to shoot the canids on sight rather than in a regulated hunting season as in the other states. But the judge said the act had to be applied to the population as a whole, without making exceptions for some states.

The court’s decision did not go down well in the west. In some western states, such as Idaho, Montana and Utah, many people feel as if they are overrun with wolves, which they see as a threat to both livestock and humans. “Rural people feel like they’ve been stepped upon. We feel like we are a big experimental zoo for the feds,” says Millage. So, members of Congress have tried to shortcut the sometimes ponderous Endangered Species Act process by simply passing a law to delist wolves. Although no species has yet been successfully delisted in this way, there were attempts to delist the wolves in the last days of the 111th Congress, from both Republican and Democratic lawmakers, but they were attached to an appropriations bill that never passed. Now, Montana Democrat senators Max Baucus and Jon Tester have proposed another delisting bill. And a reinstatement of the 2009 delisting rule has been attached to an 11 February Republican-drafted ‘continuing resolution’ that would keep the federal government running until the 2011 budget is passed. Whether the amendment will survive to become law remains to be seen.

“There definitely is a real threat the legislation will pass,” says Noah Greenwald, endangered-species programme director at the Center for Biological Diversity in Portland, Oregon. “From our perspective it would be a terrible precedent. We believe it is a scientific decision that should be made by the agency.” Secretary of the Interior Ken Salazar has been sympathetic to states that feel they have a wolf problem. He signed-off on the delisting of wolves in 2009 and, in November 2010, he met with the governors of Idaho, Montana and Wyoming, saying “I appreciate that the governors share our goal to delist the species with a responsible approach guided by science.” He is also interested in delisting a separately managed population of wolves in states including Michigan, Minnesota and Wisconsin, which also want to right to manage their wolf populations. Meanwhile, the states continue to hope for a delisting law. “We are working hard with our congressional delegation on some kind of legislative fix,” says Jon Hanian, spokesman for the governor of Idaho. “Stay tuned.”

Any such legislation will have to move forward without the aid of incoming chairman of the House Committee on Natural Resources, Republican congressman Richard “Doc” Hastings. His press secretary says that Endangered Species Act matters are “not a big priority” for Hastings and that the wolf matter is best handled at the state level. The courts will be busy with wolves as well. Greenwald says that although Idahoans may feel up to their necks in wolves, there is a national paucity of the species. The Center for Biological Diversity and other green groups intend to sue the Department of the Interior, which administers the Endangered Species Act, in March for failing to produce a unified recovery plan for the grey wolf. Western wolves are covered by the 1987 Northern Rocky Mountain Wolf Recovery Plan, a hangover from an era when US grey wolves were thought to be composed of a number of subspecies. It doesn’t cover the rest of the country’s wolves. Besides, Greenwald says that today’s scientists would be likely to call for more than the plan’s current goal of saving 300 wolves for the entire west. “We’ve learned a lot more about wolves and population viability since the 1980s,” Greenwald says.

Nature
March 8, 2011

Original web page at Nature

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Wolves can follow a human’s gaze

When humans turned wolves into dogs, we created a social companion that keys in on our every move and look. That attentiveness was one of the big effects of domestication, some scientists have argued, and a clear difference between the two species. But wolves raised with humans also pay close attention to our actions and even follow our eye gaze, say two researchers. They even pass a gazing test that dogs fail. The findings “seem to put a big nail in the coffin” of the dog-domestication theory, says Frans de Waal, a primatologist at Emory University in Atlanta who specializes in social cognition. The results should also help researchers better understand the evolution of gazing abilities overall, say the authors of the new study. Previous studies have concluded that wolves are not interested in human social cues and will not, for example, follow a pointing finger, even if that finger would lead them to food. By contrast, dogs seem to instantly grasp the connection. “For a dog, understanding pointing is a natural thing to do,” says Friederike Range, a cognitive ethologist at the University of Vienna and the lead author of the new study. “But how important is pointing to a wolf naturally?”

Because it’s not possible to test wild wolves’ abilities to follow a person’s gaze, Range and her co-author, Zsófia Virányi, a cognitive ethologist at the Wolf Science Center in Ernstbrunn, Austria, hand-raised nine wolf pups born in captivity. The pups were separated from their mothers 10 days after birth and bottle- and hand-fed for their first 5 months of life. In the ensuing months, the wolves continued to have daily social contact with humans and five adult dogs of various breeds, with which they developed close relationships. Like trainers raising dog puppies, the scientists gave the wolf pups intensive obedience training, teaching them to sit, lie down, roll over, and look into a person’s eyes. When the pups were 14 weeks old, Range and Virányi tested their ability to follow the gaze of a person who turned her head and looked into the distance. Six of the pups passed, turning to look in the same direction only seconds after the person did. And at 23 weeks old, all the pups passed the test, the team reports online today in PLoS ONE. This gaze-following ability was once thought the exclusive domain of humans. Scientists believed it evolved because we alone understood that other people have minds and thoughts. But in recent years, that barrier has been breached by apes, monkeys, goats, ravens, and a tortoise. Now that we know it’s common among animals, Range says, scientists need to revise their theories about why it evolved.

Only domesticated dogs have failed the test of following a person’s gaze to look into the distance. “That is a clear difference between dogs and wolves,” says Marc Bekoff, a cognitive ethologist at the University of Colorado, Boulder. Scientists don’t yet know why dogs fail this test, but it may be because “we train them to look at our eyes and face and not to follow our gaze,” says Range. In a second experiment, the researchers tested the wolf pups to determine whether they would follow the gaze of a person as she stood staring at a spot on the other side of a low wall. The wolf could see what the person was looking at only if it walked around the barrier. The duo also used the wolf pups’ dog companions as demonstrators, giving the dogs verbal commands to focus on the other side of the wall. Only four of the nine pups passed the test at 4 months old. But when they were 6 months old, all of the wolves reliably followed the person’s and the dogs’ gazing cues. Of the species that have passed the gazing-in-the-distance test, only apes, rooks, ravens—and now wolves—have nailed this far more difficult exam. “It really surprised us that wolves would follow our gaze [around a barrier], because it’s always been thought that wolves don’t pay attention to humans, that they don’t see us as social partners,” says Range.

The two types of gaze-following abilities seem to require different mental skills, she adds. It may be that the talent for following another’s gaze while looking in the distance is innate, almost a “reflexive reaction,” she says. But the ability to understand that your social pal is looking at something behind a barrier may develop only in species that are either highly cooperative or highly competitive—something that needs further testing, Range adds. “It’s a great study and the first, I think, that really is really biologically relevant to wolves,” meaning that it tests their natural propensities, says Bekoff. “It’s very important” to do studies like these “on socialized wolves,” adds Adam Miklosi, a cognitive ethologist at Eötvös Loránd University in Budapest. “We can then put our knowledge” about dogs into a “wider evolutionary perspective” and ultimately arrive at a better understanding of how domestication turned the wolf into a dog. That’s a change, researchers say, that required wolves to begin thinking of humans as their social pals if they were ever to end up asleep at the end of our beds.

ScienceNow
March 8, 2011

Original web page at ScienceNow

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New African wolf discovered

Scientists studying genetic evidence have discovered a new species of wolf living in Africa. The researchers have proved that the mysterious animal, known as the ‘Egyptian jackal’ and often confused with the golden jackal, is not a sub-species of jackal but a grey wolf. The discovery, by a team from Oxford University’s Wildlife Conservation Research Unit (WildCRU), the University of Oslo, and Addis Ababa University, shows that grey wolves reached Africa around 3 million years ago before spreading throughout the northern hemisphere. The new wolf is a relative of the Holarctic grey wolf, the Indian wolf and the Himalayan wolf. A report of the research appears in the journal PLoS One. Professor David Macdonald, an author of the paper and Director of Oxford University’s WildCRU, said: ‘A wolf in Africa is not only important conservation news, but raises fascinating biological questions about how the new African wolf evolved and lived alongside not only the real golden jackals but also the vanishingly rare Ethiopian wolf, which is a very different species with which the new discovery should not be confused.’

Professor Claudio Sillero, also of the WildCRU and Chair of the IUCN’s Canid Specialist Group, who has worked in Ethiopia for more than two decades, said: ‘This discovery contributes to our understanding of the biogeography of Afroalpine fauna, an assemblage of species with African and Eurasian ancestry which evolved in the relative isolation of the highlands of the Horn of Africa. Rare Ethiopian wolves are themselves a recent immigrant to Africa, and split off from the grey wolf complex even earlier than the newly discovered African wolf.’ Dr Eli Rueness of the University of Oslo, the first author of the paper, said: ‘We could hardly believe our own eyes when we found wolf DNA that did not match anything in GenBank.’ Professor Nils Chr. Stenseth, an author of the paper and the Chair of the Centre for Ecological and Evolutionary Synthesis (CEES) said: ‘this study shows the strengths of modern genetic techniques: old puzzles may be solved.’ The team also found genetically very similar specimens to this new wolf in the highlands of Ethiopia, 2,500 km from Egypt, suggesting that the new species is not just found in Egypt.

Professor Afework Bekele at Addis Ababa University added: ‘This shows how genetic techniques may expose hidden biodiversity in a relatively unexplored country like Ethiopia.’ Golden jackals are regarded by the International Union for Conservation of Nature as not threatened — a “species of least concern” — but the newly discovered African wolf may be much rarer. The team believe it is a priority for both conservation and science to discover its whereabouts and numbers. Professor Sillero said: ‘It seems as if the Egyptian jackal is urgently set for a name-change, and its unique status as the only member of the grey wolf complex in Africa suggests that it should be re-named ‘the African wolf’.

Science Daily
February 22, 2011

Original web page at Science Daily

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The black-footed ferret has bucked the biodiversity trend thanks to conservation efforts – though it remains endangered

A fifth of vertebrate species are at risk of extinction, but biodiversity decline would have been considerably worse without conservation efforts, an analysis published today suggests. The study, published in Science which summarizes the status of more than 25,000 mammals, birds and amphibians, was released to coincide with the UN Convention on Biological Diversity meeting in Nagoya, Japan, where delegates this week are expected to set targets to halt loss of the world’s biodiversity by 2020. “We’ve failed in meeting the 2010 targets to cut species loss ‘significantly’ by this year,” says Michael Hoffmann of the International Union for the Conservation of Nature (IUCN) in Cambridge, UK, who led the vertebrate study, “but the aim of our paper is to demonstrate that actually conservation is making a difference”. A second study published in the same issue, points out that computer models currently used to estimate future biodiversity loss are unreliable and inconsistent, which will hamper attempts to predict how policy decisions made in Nagoya will affect the world’s flora and fauna.

“We have to work on narrowing down the likely dimensions of the crisis,” says Henrique Pereira at the University of Lisbon in Portugal, who led this work. “At the moment we don’t know whether we will lose 1% of biodiversity or between 40% and 50% by 2050.” Using an index of extinction risk based on category movements in the IUCN Red Lists of threatened mammals, reptiles, birds, amphibians and fishes — including some listings dating back as far as 1980 — Hoffmann’s team showed that, on average, 52 vertebrate species have moved one Red List category closer to extinction every year. Amphibians are the most likely to be sliding towards extinction: 42% are classified as ‘threatened’, mainly due to the poorly understood infectious disease chytridiomycosis, which has decimated populations around the world. Increases in extinction risk are most marked in Southeast Asia, although wealthier countries such as the United States and Australia have also suffered declines. Rhys Green, professor of conservation science at the University of Oxford, says the paper is important because it pulls together disparate assessments — “including the less ‘cuddly’ groups”. But the study also estimates that biodiversity declines would have been at least one-fifth as much again if there had been no effort to halt habitat loss, curb hunting and tackle invasive species. “People don’t believe that we can really do anything about the situation,” says Hoffmann, “but if it hadn’t been for the conservation effort, the declines we’ve seen would have been much worse.”

The golden lion tamarin, still endangered, has benefited from three decades of conservation work to strengthen population numbers. And the true impact of conservation may be even more positive. The figures are a “woeful underestimate”, says Hoffmann — partly because it is hard to spot species that would have slipped IUCN categories but haven’t because of conservation efforts. Tackling invasive species seems to have produced the best results so far, but probably only because this strategy is particularly effective at lessening threats on isolated islands, Hoffmann says. In some cases, conservation efforts have brought species back from the brink, such as those that repopulated parts of North America with the still-endangered black-footed ferret (Mustela nigripes) and a three-decade programme that saw the golden lion tamarin (Leontopithecus rosalia) downlisted to “endangered” from “critically endangered” in 2003. Meanwhile, the review of computer modelling of biodiversity, led by Pereira, says that inconsistent assumptions and an absence of hard data on the ground are the main barriers to predicting how biodiversity will change in the future. Some studies extrapolate trends from previous correlations of changes in land use or climate with biodiversity loss. Others include details of the processes by which a species will become extinct as their surroundings change. All suggest we are facing a biodiversity crisis, but because they use different scenarios for climate and land-use change, estimates of the extent of future loss and of our ability to mitigate it diverge widely between the models.

“I think the biggest challenge for the community is to develop a better observation network for biodiversity change,” says Pereira. And, he adds, “We need a bigger effort from the community in terms of comparing projections for the same set of scenarios. Then we could ascertain whether variations in outcomes were caused by the different models or by the different scenarios analysed.” “This review definitely needed to be written,” says Green of Pereira’s paper. “It paints a somewhat depressing picture, as there’s still a lot of uncertainty.” Both Pereira and Green hope that the establishment of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services — a biodiversity-based equivalent of the Intergovernmental Panel on Climate Change — will rally the biodiversity research community to work together on improving models and making sure that outcomes are comparable, and to establish better monitoring systems. Although the Nagoya negotiations are currently stalling on detailed aspects of conservation funding and access to the resources of ecologically rich nations, Hoffmann remains optimistic. As he concludes from his review of conservation efforts: “We can really turn things around and that’s a powerful message — you should never give up hope.”

Nature
November 9, 2010

Original web page at Nature

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Learning the mongoose ways

A banded mongoose pup will learn its foraging technique from its escort and preserve the tradition well into adulthood, researchers report. The select club of brainy critters known for carrying traditions—among them humans, primates, whales, and dolphins—has an unlikely new member: the banded mongoose. Researchers have found that the furry African carnivore learns by imitation as well and carries what it learns well into adulthood. Experts say the discovery offers the first direct observation of animals passing down traditions in the wild. The mongoose is better known for its unique social system than for its brainpower. When mongoose pups emerge from the den, they try out and eventually choose one adult—usually an older sibling, cousin, or uncle, not a parent—who becomes their “escort” or chaperone during infancy. The escort protects, feeds, and plays with the pup as it grows, and the pair spends almost all its time together until the pup reaches adulthood. The relationship made Corsin Müller, an animal cognition expert at the University of Vienna, wonder if the escort teaches the pup any behaviors; that is, whether the escort is passing down “culture” or tradition to the pup.

To find out, Müller and a colleague at the University of Exeter in the United Kingdom took advantage of another mongoose quirk. When eating hard-shelled prey, such as eggs or rhinoceros beetles, some mongooses bite into the item, others hurl it against a hard surface to smash it open, and still others switch between the techniques. Each mongoose sticks to its preferred behavior, even if other members of the same group choose a different tactic. Watch and learn. A mongoose escort smashes or bites a food-filled plastic egg as his pup looks on. As an adult, the pup will adopt its escort’s preferred foraging technique or “tradition” during its own encounters with the egg. The researchers devised a new food for wild mongooses to forage, a plastic egg filled with rice and fish that could be opened with either technique. Then they watched as 42 pups and their escorts encountered the engineered egg. In keeping with their preferences, the escorts either bit or smashed it, and a handful consistently ignored it. Two months later, when the escort relationships had ended and the pups were on their own, the researchers again presented the plastic eggs. The newly independent mongooses did as they’d seen their escorts do, adopting their elders’ biting or smashing strategy for opening the egg or ignoring it altogether. The learned behavior persisted—1 year later, as adults, the mongooses continued to approach the plastic eggs as their escorts had taught them more than 70% (for smashers) or 80% (for biters) of the time.

The result suggests that each mongoose pup copies a foraging tradition from its escort and preserves it as it grows older, Müller reports today in Current Biology. Spotting social learning in the intellectually “unspectacular” mongoose also hints that such learning is widespread, adds Müller. “There’s no reason why smaller-brained animals should not have traditions,” he says.

ScienceNow
June 22, 2010

Original web page at ScienceNow

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The bigger the animal, the stiffer the ‘shoes’: Carnivores’ feet ‘tuned’ to their body size

If a Tiger’s feet were built the same way as a mongoose’s feet, they’d have to be about the size of a hippo’s feet to support the big cat’s weight. But they’re not. For decades, researchers have been looking at how different-sized legs and feet are put together across the four-legged animal kingdom, but until now they overlooked the “shoes,” those soft pads on the bottom of the foot that bear the brunt of the animal’s walking and running. New research from scientists in Taiwan and at Duke University has found that the mechanical properties of the pads vary in predictable fashion as animals get larger. In short, bigger critters need stiffer shoes.

Kai-Jung Chi, an assistant professor of physics at National Chung Hsing University in Taiwan ran a series of carefully calibrated “compressive tests” on the footpads of carnivores that have that extra toe halfway up the foreleg, including dogs, wolves, domestic cats, leopards and hyenas. She was measuring the relative stiffness of the pads across species — how much they deformed under a given amount of compression. “People hadn’t looked at pads,” said co-author V. Louise Roth, an associate professor of biology and evolutionary anthropology who was Chi’s thesis adviser at Duke. “They’ve been looking at the bones and muscles, but not that soft tissue.” Whether running, walking or standing still, the bulk of the animal’s weight is borne on that pillowy clover-shaped pad behind the four toes, the metapodial-phalangeal pad, or m-p pad for short. It’s made from pockets of fatty tissue hemmed in by baffles of collagen. Chi carefully dissected these pads whole from the feet of deceased animals (none of which were euthanized for this study), so that they could be put in the strain meter by themselves without any surrounding structures.

Laid out on a graph, Chi’s analysis of 47 carnivore species shows that the area of their m-p pads doesn’t increase at the same rate as the body sizes. But the stiffness of pads does increase with size, and that’s what keeps the larger animal’s feet from being unwieldy. The mass of the animal increases cubically with its greater size, but the feet don’t scale up the same way. “A mouse and an elephant are made with the same ingredients,” Roth said. “So how do you do that?” Earlier research had found that the stresses on the long bones of the limbs stay fairly consistent over the range of sizes, in part because of changes in posture that distribute the stresses of walking differently, Roth said. But that clearly wasn’t enough by itself. The researchers also found that larger animals have a pronounced difference in stiffness between the pads on the forelimbs and the pads on the hind limbs. Bigger animals have relatively softer pads on their rear feet, whereas in smaller animals the front and rear are about the same stiffness. Chi thinks the softer pads on the rear of the bigger animals may help them recover some energy from each step, and provide a bit more boost to their propulsion. (Think of the way a large predator folds up its forelimbs and launches itself with its hind legs.) “It is as if the foot pads’ stiffness is tuned to enhance how the animal moves and how strength is maintained in its bones,” Roth said. The research appeared February 23 in the Journal of the Royal Society, Interface.

Science Daily
March 23, 2010

Original web page at Science Daily

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Nothing to fear from the big bald wolf

Shortly after gray wolves were reintroduced to Yellowstone National Park in 1995, Daniel MacNulty was puzzled by something. The breeding pair in one of the packs frequently stopped during their elk hunts to rest. “They sat on the sidelines while their offspring did the work,” says MacNulty, an ecologist from Michigan Technological University in Houghton. “After their kids made the kill, they would amble up to feed.” Laziness? Not at all. The two were almost 5 years old, which MacNulty has learned is fairly old age for wolves. His new study is one of the first to look at the effects of aging in predators, and it raises questions about current methods of controlling wolf populations. “It’s an exciting paper and should become a classic,” says ecologist John Fryxell of the University of Guelph in Canada. MacNulty has followed 94 radio-collared wolves in Yellowstone for 13 years, closely monitoring their hunts for two 30-day periods during each of those years. His research on these individual canids shows that wolves age rapidly. Indeed, by age 2 they’re in their hunting prime, drawing on youthful endurance and sudden bursts of speed to take down elk. But just as quickly, they lose that talent, MacNulty’s team reports online in Ecology Letters. “Wolves are old when they’re 4,” he says. The median life span for wolves in Yellowstone is 6 years, although some have lived as long as 10. Those older wolves manage to survive because the younger ones in their pack pick up the slack, killing elk and letting all the pack members feed. Older wolves are also heftier and may come in at the end of a hunt to use their weight to help pull down the elk, says MacNulty.

As one might expect, aging predators are good news for prey. The wolves’ kill rate on elk in Yellowstone declined significantly as the number of geriatric hunters in the wolf population increased. And that could have cascading effects on the ecosystem. For instance, elk may linger and browse on woody plants when elderly wolves are around. More browsing could slow the recovery of willows and aspen trees, which have come back since the wolves’ reintroduction. Fryxell says ecologists are starting to realize that age needs to be included in models of predator-prey abundance. Game managers should pay attention as well. Most managers who want to boost numbers of elk and deer think all you need to do is kill wolves, says ecologist Christopher Wilmers of the University of California, Santa Cruz. “But this study shows you’re probably increasing your problem, since you’ll end up with younger wolves that kill more prey.” That’s because when a pack vanishes or is weakened and loses its territory, he says, younger wolves often move in. “You’re better off leaving the wolves alone.”

ScienceNow
November 3, 2009

Original web page at ScienceNow

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Rabies in foxes, Aegean region, Turkey

At the end of the 1990s in the Aegean region of Turkey, rabies rapidly spread among foxes. This spread likely resulted from spillover infection from dogs and led to increased rabies cases among cattle. To control this outbreak, oral rabies vaccination of foxes has been used. In Turkey, dog-mediated (spread by dogs as host species) rabies dominates the epidemiology of rabies. During 1990–2000, a total of 2,856 rabies cases were reported from Turkey; dogs (Canis lupus familiaris) accounted for 78% of reported cases, whereas wildlife accounted for only 1.6% (data from 44 issues of Rabies Bulletin Europe, available from www.who-rabies-bulletin.org). In the past decade (1998–2007), however, an increasing number of rabies cases in foxes (Vulpes vulpes) have been reported from the Aegean region in western Turkey. Rabies in foxes has been reported incidentally from other regions in Turkey, especially from the central and eastern parts. Rabies cases in foxes have been considered to be rare, dead-end, spillover events from rabid dogs and to have no epidemiologic significance. However, surveillance data from most of these regions are limited; therefore, whether rabies in wildlife occurs independently from rabies in dogs is unknown. Sufficient data are available for the Aegean region, and phylogenetic studies have concluded that rabies recently spilled over from domestic dogs to foxes in this area.

The Aegean region is characterized by mountain ranges, except for the coastal plains, where most of the human population is concentrated and where ≈3.5 million persons live in Turkey’s third largest city, Izmir. This economic and industrial center lies in a predominantly agricultural area. Before 1999, rabies in the Aegean region was predominantly mediated by dogs, and no clear movement from an urban focus was noted. Most cases were observed in and around the city of Izmir. The number of rabies cases had decreased notably in the Aegean region, from 137 cases in 1988 to only 2 cases in 1995, after which the number started to increase again. To determine more about the epidemiology of this disease, we analyzed the spatial and temporal incidence of rabies in 8 provinces of the Aegean region during 1998–2007. We emphasized the shift from dog-mediated to fox-mediated rabies and the consequences to the disease profile in this area.

During the study period, animals from the Aegean region suspected of having rabies were submitted for rabies diagnosis to the Bornova Veterinary Control and Research Institute in Izmir. Routine rabies diagnosis was based on detection of Negri bodies, followed by fluorescent antibody test results; for negative samples, the mouse inoculation test was also performed. From 1998 through 2007, a total of 3,737 specimens were submitted; of these, 118 samples could not be examined because the samples were of poor quality. Analysis of the data for the 3 major animal species submitted (cattle, dogs, and foxes) during this period showed dramatic changes in the number of rabies cases for each of these species. In 1998, no rabies in foxes was reported, and dogs clearly dominated rabies submissions. However, in subsequent years, rabies emerged in foxes; this emergence coincided with an increased number of rabid cattle reported and a decreased number of rabid dogs. The annual number of rabid dogs correlated only weakly with total number of dogs submitted for testing; coefficient of determination (R2) was 0.56. However, this correlation was markedly higher for cattle and foxes (R2 = 0.99 for both species). This finding indicates that the lower number of rabid dogs did not result only from decreased surveillance for this species.

From 1998 through 2000, almost all cases in the 3 most affected species were reported from the area between the cities of Izmir and Manisa, and the epizootic progressed in a wave-like fashion southward; in 3 years, the area of rabies cases moved ≈150 km. In 2003, the southeastward movement of the rabies epidemic slowed and, in 2004, appeared to halt. In 2005, cases again increased in the northern part of Aydin Province, which borders Izmir Province. In 2006, no clear movement of this outbreak was observed. The northern Aegean region may not be a suitable habitat for foxes and therefore may not have supported a sufficient number of foxes for an epizootic. Reliable data on fox density or even the number of foxes shot are lacking. Several cases of rabies in foxes were reported in 2006 from the area where the fox outbreak had started 7 years earlier. In 2007, rabies in foxes was still reported from this area, and the outbreak in Aydin had moved eastward and established itself in the neighboring province of Denizli.

The high number of free-roaming dogs and the low vaccination coverage of the dog population would have provided ample opportunities for infected dogs to transmit the virus to foxes. Hence, foxes (or a fox) in the Izmir area are assumed to have become infected, and rabies then spread in the fox population. The close association of the sequences of rabies virus isolates from dogs and foxes in this area supports a recent transfer. However, the phylogenetic data provide no indication of the direction of virus transmission. The lack of reported rabies in a fox in this area since 1986 suggests that dogs transferred the virus to foxes, leading to the present rabies outbreak, not the reverse. Since 1999, rabies has moved predominantly south and southeast at ≈40–50 km per year from the area where the first cases in foxes were reported. This movement was associated with increases in the number of rabies cases in foxes and cattle until 2003, when the number of cases sharply declined after mass vaccination of cattle. Since 2003, the numbers of rabid dogs and rabid foxes reported each year has remained approximately the same. However, the number of dogs submitted for rabies diagnosis is ≈9× higher than the number of foxes submitted. Furthermore, only 20% of the dogs tested were rabies virus–positive, compared with almost all (95%) of the foxes; therefore, the true number of rabid foxes can be assumed to exceed the number of rabid dogs.

Although during the 10 years of the study period, 6 cases in humans in the study area were reported, none were linked to foxes. Hence, the public health risks associated with rabid foxes are relatively small compared with those associated with rabid dogs. However, if not eliminated, rabies in foxes will form a reservoir for disease persistence. A high number of rabies cases in cattle causes an economic loss. Mass vaccination of cattle reduces these losses but does not solve the problem. After the initial epizootic, the disease seems to have become endemic to the Aegean region. Preventing the spread of rabies to foxes in unaffected areas is crucial. Therefore, to control the present outbreak, a campaign to orally vaccinate foxes against rabies in the affected provinces of Turkey was initiated during February 2008 and conducted again in 2009.

Emerging Infectious Diseases
October 20, 2009

Original web page at Emerging Infectious Diseases

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Wolf in coyote’s clothing

Farmers depend on hybrid vigor for improved crop yields, as seeds produced from different strains of, say, corn, can lead to superior crops. Hybrid vigor seems to have worked for coyotes in the Northeastern United States as well, according to a genetic study and physical analysis of the animals: Coyotes in this part of the United States are bigger than their western counterparts because, as their ancestors migrated into the territory, they mated with wolves along the way. Interested in how animals spread from one region to another, Roland Kays has long been fascinated by coyotes. Originating in the Great Plains, these wild canids have moved eastward over the past 90 years into a mix of forests and fields well suited for the deer and small prey these animals thrive on. Curiously, though, coyotes expanded five times faster via a northern route through Ontario, Canada, than through a more southern route through Ohio. Kays, a wildlife biologist with the New York State Museum in Albany, New York, wondered if mating and hybridization with Canadian wolves influenced this rapid spread. Wolves had been extirpated from Ohio long ago, but they still survive in Ontario.

Over the past 9 years, Kays has photographed coyotes with remote motion sensor cameras, collected roadkill and scat, and obtained tissue and bones from fur trappers, hunters, and others. This material provided Kays and his colleagues with data to nail down the influence of wolves on eastern coyotes. The researchers sequenced a piece of mitochondrial DNA from more than 680 coyotes and measured the skulls of 196 animals. They grouped the DNA sequences by similarity and thus were able to trace the lineages of the various animals and determine their migration patterns. The data showed that indeed coyotes arrived along southern and northern routes, with the descendents of the southern travelers having DNA much like that of their western counterparts, the researchers report today in Biology Letters. But the offspring of animals that had come along the northern route are much less genetically diverse–suggesting that a few individuals took this route–and have wolf DNA, most likely because their ancestors interbred with Great Lakes wolves. “The wolves are gone, but part of their genomes are still here,” says collaborator Jeremy Kirchman, also with the New York State Museum. “This has allowed these coyotes to be so successful.” The researchers did not find evidence of much hybridization with domestic dogs, as some have expected, says Kirchman.

Northeastern coyotes are not just larger but they also have wolflike features, the researchers found. These coyotes have wider mouths, with more surface area on the skull where chewing muscles attach, giving them a stronger bite for killing bigger prey. They eat more deer and they are comfortable in forests, much like wolves. More genetic studies are needed to pin down that wolf genes are responsible for all of these changes. But it’s clear that “in many ways they are acting like a small wolf, but they look like coyotes,” says Matthew Gompper, a wildlife biologist at the University of Missouri, Columbia, who was not involved in the study. The findings also put an interesting twist on hybrid vigor, say Gompper. Although such crossbreeding often yields hardier plants, “the rule of thumb [for animals] is that hybrids do less well,” he says. “In this case, the hybrids appear to have greater fitness. It shows the importance of hybridization in providing the meat for adaptation.” So what exactly are the wild canids in Northeastern America–coyotes or wolves? That puzzler will give evolutionary biologists a bone to gnaw on for a while.

ScienceNow
October 6, 2009

Original web page at ScienceNow