Tag: Carnivores

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Human ‘super predator’ more terrifying than bears, wolves and Human ‘super predator’ more terrifying than bears, wolves and dogs

Bears, wolves and other large carnivores are frightening beasts but the fear they inspire in their prey pales in comparison to that caused by the human ‘super predator.’

A new study by Western University demonstrates that smaller carnivores, like European badgers, that may be prey to large carnivores, actually perceive humans as far more frightening. Globally, humans now kill smaller carnivores at much higher rates than large carnivores do, and these results indicate that smaller carnivores have learned to fear the human ‘super predator’ far more than they fear their traditional enemies.

These findings by Liana Zanette and Michael Clinchy from Western’s Faculty of Science, in collaboration with celebrated British biologist David Macdonald from University of Oxford’s Wildlife Conservation Research Unit (WildCRU) and others, were published this week in Behavioral Ecology.

Zanette, a professor in Western’s Department of Biology, and her colleagues experimentally demonstrated that smaller carnivores, like badgers, foxes and raccoons, that may appear to be habituated to humans because they live among us, are actually experiencing elevated levels of fear — living in fear of the human ‘super predator’ in human-dominated landscapes.

“Our previous research has shown that the fear large carnivores inspire can itself shape ecosystems. These new results indicate that the fear of humans, being greater, likely has even greater impacts on the environment, meaning humans may be distorting ecosystem processes even more than previously imagined,” explains Zanette, a wildlife ecologist. “These results have important implications for conservation, wildlife management and public policy.”

By frightening their prey, large carnivores help maintain healthy ecosystems by preventing smaller carnivores from eating everything in sight, and the loss of this ‘landscape of fear’ adds to conservation concerns regarding the worldwide loss of large carnivores. Fear of humans has been proposed to act as a substitute, but these new results demonstrate that the fear of humans is qualitatively different and cannot be expected to fulfill the same ecosystem function.

The team conducted the study on Europeans badgers in Wytham Woods, just outside of Oxford (UK). To experimentally compare their relative fearfulness, the team played badgers the sounds of bears, wolves, dogs and humans in their natural habitat and filmed their responses, using hidden automated speakers and cameras. Whereas hearing bears and dogs had some effect, simply hearing the sound of people speaking, in conversation, or reading passages from books, prevented most badgers from feeding entirely, and dramatically reduced the time spent feeding by those few badgers that were brave enough to venture forth — while hearing the sound of the human ‘super predator.’

https://www.sciencedaily.com/  Science Daily

https://www.sciencedaily.com/releases/2016/07/160725135357.htm Original web page at Science Daily

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Global carnivore conservation at risk, new report shows

A new study confirms that the global conservation of carnivores is at risk. Published in Scientific Reports, the report models future global land conversion and estimates this will lead to significant range loss and conflict with local people in regions critical for the survival of already threatened carnivore species.

Organized by researchers from the University of Helsinki in collaboration with an international team of conservation and land use change scientists the study concludes that immediate action is needed to prevent habitat loss and conflict with humans in priority areas for carnivore conservation.

Lead author Dr. Enrico Di Minin of University of Helsinki explained, “We assessed how expected land use change will affect priority areas for carnivore conservation in the future. The analysis revealed that carnivores will suffer considerable range losses in the future. Worryingly, it seems that the most important areas for carnivore conservation are located in areas where human-carnivore conflicts are likely to be most severe.”

Di Minin continued, “Presently, South American, African, and South East Asian countries, as well as India, were found to contribute mostly to carnivore conservation. While some of the most charismatic species, such as the tiger and giant panda were found to be at high risk under future land use change, smaller, less charismatic species, with small ranges were found to be equally threatened by habitat loss.”

Carnivores include some of the most iconic species that help generate funding for biodiversity conservation and deliver important benefits to humans. Protecting carnivores will conserve many other bird, amphibian, reptile and mammal species that live in priority areas for carnivore conservation.

Dr. Luke Hunter, President and Chief Conservation Officer of Panthera, the global wild cat conservation organization, and a co-author of the paper shared, “Carnivores like big cats have been squeezed out of their ranges at alarming rates for decades now, and we can now see that habitat loss and its shock waves on wildlife are only on the rise. In order to protect our planet’s landscape guardians, a far greater financial investment from the international community is needed for range-wide conservation approaches, both within and outside of protected areas where carnivores roam.”

Professor Rob Slotow from the University of KwaZulu-Natal, another co-author in the paper, in South Africa emphasizes that reducing conflict with humans outside of protected areas is pivotal. “Most priorities for carnivore conservation are in areas in the global south where human populations are increasing in size, agriculture is intensifying, and human development needs are the highest. There is need to implement conservation strategies that promote tolerance for carnivores outside protected areas and focus on the benefits that people derive from these species.”

https://www.sciencedaily.com/  Science Daily

https://www.sciencedaily.com/releases/2016/04/160404090709.htm  Original web page at Science Daily

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Intense competition for reproduction results in violent mass evictions

Intense levels of reproductive competition trigger violent evictions of male and female banded mongooses from their family groups, University of Exeter researchers have found. Dominant animals in this species are unable to stop subordinates breeding, leaving them with no resort except to throw them, kicking and screaming, out of the group.

Scientists observed a population of wild banded mongooses in Queen Elizabeth National Park in south west Uganda in a 16 year study. They found that evictions were extremely aggressive events resulting in the forcible expulsion of a group of females, sometimes with a group of males alongside them.

These mass eviction events were most likely to occur when the level of competition over who reproduces was at its greatest. Female banded mongooses were evicted when there were lots of breeding females in the group, and males were more likely to be evicted alongside females when there were lots of males competing to breed.

Banded mongooses live in cooperatively breeding family groups, meaning that all group members help to raise pups even if they don’t breed themselves. All adult females breed together, giving birth to a communal litter on exactly the same day. Usually individuals live together peacefully but occasionally the group erupts into violence, which results in some individuals being aggressively attacked and driven away from the group.

The study, published in the journal Proceedings of the Royal Society B, shows that reproductive competition destabilises cooperative groups and that eviction can be a major source of gene flow in social animals.

Faye Thompson, a PhD researcher at the University of Exeter’s Centre for Ecology and Conservation and the lead author of the study, said: “Banded mongooses, like many social animals, often show extreme levels of cooperation but occasionally these harmonious relations break down. Dominant females, and sometimes males too, aggressively evict members of their own family to reduce their level of reproductive competition.

“Banded mongooses rarely disperse of their own accord, and so eviction is one of the only ways that individuals form new groups. These eviction events result in the mass movement of genes through the population.”

Professor Michael Cant from the University of Exeter’s Penryn Campus, Cornwall, who leads the Banded Mongoose Research Project, said: “We’ve been studying these animals for 20 years, but it’s only now that we are beginning to understand the long-term dynamics of the system. This work shows that within-group conflicts can have effects not only on the individuals involved, but also on the genetic structure of the wider population.”

https://www.sciencedaily.com/  Science Daily

https://www.sciencedaily.com/releases/2016/03/160301204921.htm  Original web page at Science Daily

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Animals with larger brains are best problem solvers, study shows

Animals with larger brains are best problem solvers, study shows

Why did some species, such as humans and dolphins, evolve large brains relative to the size of their bodies? Why did others, such as blue whales and hippos, evolve to have brains that, compared to their bodies, are relatively puny?

It has long been thought that species with brains that are large relative to their body are more intelligent. Despite decades of research, the idea that relative brain size predicts cognitive abilities remains highly controversial, because there is still little experimental evidence to support it. However, a new paper describes a massive experiment that supports the theory.

Sarah Benson-Amram, an assistant professor in the Department of Zoology and Physiology at the University of Wyoming, is the lead author on a new paper, titled “Brain size predicts problem-solving ability in mammalian carnivores.” It shows that carnivore species with larger brains relative to their body size are better at solving a novel problem-solving task. The paper appears in the Proceedings of the National Academy of Sciences.

Other authors of the study include Kay Holekamp, a University Distinguished Professor at Michigan State University; Ben Dantzer, an assistant professor at the University of Michigan; Eli Swanson, a postdoctoral researcher at the University of Minnesota; and Greg Stricker, also from Michigan State University.

The authors traveled around the country to nine different zoos and presented 140 animals from 39 different mammalian carnivore species with a novel problem-solving task. The study included polar bears, arctic foxes, tigers, river otters, wolves, spotted hyenas and some rare, exotic species such as binturongs, snow leopards and wolverines. Each animal was given 30 minutes to try to extract food from a closed metal box. To access the food, an animal had to slide a bolt latch, which would allow a door to open. The box was baited with the favorite food of the study animal, so red pandas received bamboo and snow leopards got steak.

The main result is that species with larger brains relative to their body size were more successful than species with relatively smaller brains.

“This study offers a rare look at problem solving in carnivores, and the results provide important support for the claim that brain size reflects an animal’s problem-solving abilities — and enhance our understanding of why larger brains evolved in some species,” Benson-Amram says.

Dantzer explains that, “Overall, 35 percent of animals (49 individuals from 23 species) were successful in solving the problem. The bears were the most successful, solving the problem almost 70 percent of the time. Meerkats and mongooses were the least successful, with no individuals from their species solving the problem.”

Interestingly, larger animals were less successful overall than smaller-bodied animals. The paper also reports that manual dexterity did not affect problem-solving success.

In addition to examining the influence of brain size on problem-solving abilities, the authors also asked whether species that live in larger average group sizes are more successful problem solvers.

Holekamp explains, “A hypothesis that has garnered much support in primate studies is ‘the social brain hypothesis,’ which proposes that larger brains evolved to deal with challenges in the social domain. This hypothesis posits that intelligence evolved to enable animals to anticipate, respond to and, perhaps, even manipulate the actions of others in their social groups. If the social brain hypothesis is correct, then we would expect that species that live in larger social groups would be more intelligent. However, we did not find any support for the social brain hypothesis in this study. There was no indication that social group size influenced problem-solving abilities.”

http://www.sciencedaily.com/  Science Daily

http://www.sciencedaily.com/releases/2016/01/160125155732.htm  Original web page at Science Daily

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* Coexisting with dangerous carnivores

* Coexisting with dangerous carnivores

Life is replete with things we don’t like that are good for us. For instance, Brussels sprouts when you were a kid, or common house spiders under your eaves. But with enough information about benefits and risks, combined with the passage of time, we learn to accept and sometimes embrace formerly unpleasant or misunderstood things.

But what if those things are potentially dangerous? How can you sway a population to tolerate, say, endangered tigers and thus enhance worldwide conservation efforts? That was the question facing Neil Carter, assistant professor in the Human-Environment Systems program in Boise State University’s College of Innovation and Design.

Carter was part of a study to measure the psychological predictors of tolerance for tigers in the Bangladesh Sundarbans, where the large carnivores have a rocky and sometimes violent relationship with local communities.

That study recently was published in the journal PLOS ONE with the title, “Toward Human-Carnivore Coexistence: Understanding Tolerance for Tigers in Bangladesh.” Lead author is Chloe Inskip; additional authors include Carter, Shawn Riley, Thomas Roberts and Douglas MacMillan.

“The study highlights the importance of understanding the social and psychological drivers of tolerance or intolerance for wildlife,” said Inskip. “By doing so we can develop interventions appropriate for building tolerance for endangered species, including those which pose a threat to people.”

Bangladesh’s Sundarbans region, home of many of Asia’s dwindling number of remaining tigers, also is home to some of the most severe carnivore-human conflict in the world. Peppered with mangrove forests, it has one of the highest rates of people killed per year by tigers.

The Bengal tiger is the national animal of Bangladesh and, as a symbol of courage and power, has strong cultural and religious significance. More importantly, the animal is central to helping maintain a healthy ecosystem and contributing to biodiversity. Because of this, tigers enjoy a highly protected status in Bangladesh, although some illegal tiger killings do still occur.

Unlike other tiger habitats in Asia, the Sundarbans mangrove forest included in this study is perpetually flooded, making it an attractive fishing ground for local farmers. Hundreds of thousands of locals also tap the forest each year for fuel wood, livestock fodder, honey, and other household resources. People are most often attacked by tigers when they enter the forest.

“Our question was: Do people tolerate this?” said Carter. “And if so, why? And how can we increase that tolerance while balancing the risks and costs? How can we re-orient interventions toward the positive aspects of living near these animals?”

Carter and his co-researchers expected to find that negative interactions with tigers, experienced either directly or indirectly by almost every household they surveyed, influenced residents’ tolerance levels. Instead, they found that attitudes were more closely aligned with villagers’ cultural and religious beliefs and risk perceptions.

In fact, 93 percent of those surveyed said they believed tigers should be protected. Forty-seven percent were supportive of an increasing tiger population, while only 22 percent felt the population should decrease.

Study findings could be used to develop interventions that enhance tolerance for tiger presence in Bangladesh and elsewhere. These could include social marketing campaigns, with education and awareness components tailored to specific sites. Other possible uses include reducing the perceived risk from tigers, such as tiger-proofing houses and livestock pens.

“Local communities’ support for carnivore conservation efforts and tolerance of species presence will be key to carnivore conservation across increasingly anthropogenic landscapes and shape efforts to develop tolerance-promoting strategies,” the study concludes.

A similar study could benefit the western United States, where residents are coming into more frequent contact with large carnivores as more and more open space is developed. For instance, evidence shows that beliefs about cougar populations in Montana influence how locals accept and view the carnivores. Unlike in Bangladesh, where tigers have been present for centuries, the threat of large carnivores in populated areas is new in most western states, adding a different twist to risk perception.

While Carter has had a lifelong fascination with tigers, he now is expanding his work to broader human-carnivore interactions. He currently is part of a team that submitted a proposal to the National Science Foundation to fund a study of coyote populations in the Owyhees and he is interested in also looking at how local residents view cougars and, possibly, wolves.

http://www.sciencedaily.com/  Science Daily

http://www.sciencedaily.com/releases/2016/01/160122145450.htm  Original web page at Science Daily

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Endangered foxes on Catalina Island get promising treatment to reduce ear tumors

A team of scientists led by UC Davis found alarming rates of ear mites and ear canal tumors in the endangered foxes. Ear mite treatments they initiated have since dramatically reduced the problem, their studies show.

Until recently, endangered foxes on California’s Catalina Island were suffering from one of the highest prevalences of tumors ever documented in a wildlife population, UC Davis scientists have found. But treatment of ear mites appears to be helping the wild animals recover. Roughly half of adult foxes examined between 2001 and 2008 had tumors in their ears, with about two-thirds of those malignant, according to a UC Davis study published this month in the journal PLOS ONE.

More than 98 percent of the foxes were also infected with ear mites. These mites appear to be a predisposing factor for ear tumors in the Santa Catalina Island fox. “We established a high prevalence of both tumors and ear mites, and hypothesized that there was something we could potentially do about it, which now appears to be significantly helping this population,” said Winston Vickers, lead author of the prevalence study and an associate veterinarian with the UC Davis Wildlife Health Center at the UC Davis School of Veterinary Medicine.

Working closely with researchers from the Institute for Wildlife Studies and Catalina Island Conservancy, the scientists conducted one of the few studies to estimate disease prevalence in an entire free-living wildlife population.

A complementary study, also led by UC Davis and published in PLOS ONE today, found that treatments with acaracide, a chemical agent used to kill ear mites in dogs and cats, reduced the prevalence of ear mite infection dramatically, from 98 percent to 10 percent among treated foxes at the end of the six-month trial. Ear canal inflammation and other signs of developing ear tumors also dropped.

“It’s rare to have a success story,” said the ear mite study’s lead author, Megan Moriarty, a student with the UC Davis School of Veterinary Medicine when the study began and currently a staff research associate at the UC Davis Wildlife Health Center. “It was interesting to see such striking results over a relatively short time period.”

Santa Catalina Island foxes are intensively managed by the Catalina Island Conservancy. In 2009, when the mite treatment study began, the Conservancy added acaracide to the variety of preventative treatments they administer to the foxes each year.

The Conservancy confirms that, in the years since, the overall prevalence of ear mites has dramatically declined in the areas they normally catch and treat foxes, as have the rates of tissue masses in the ear canals, suggesting reduced tumor presence.

“The annual prophylactic acaracide treatment has greatly improved the overall condition of the foxes’ ear canals,” said Julie King, the Conservancy’s director of Conservation and Wildlife Management and co-author of both studies. “Within just a few months post treatment, the presence of wax, infection, inflammation, and pigmentation virtually disappear. We have also noted an apparent reduction in the number of tumors observed, despite the fact that the absence of wax and other obstructions has made them easier to detect.

Conservancy biologists have also documented a cascade effect on the foxes’ offspring, since most young foxes get the ear mites from their parents. “Prior to treatment in 2009, approximately 90 percent of all pups handled had ear mites, whereas by 2015, mites were detected in only 15 percent of new pups.” King said.

The studies pose new questions. For instance, the mite treatment certainly reduces the prevalence and severity of mite infection, as well as risk factors for tumor development, but what effect will it have on overall tumor and cancer rates for these foxes in the long term?

Also, ear mites infect other Channel Island foxes, but those foxes don’t develop ear canal tumors. So why are Santa Catalina Island foxes predisposed to these tumors and not other Channel Island foxes? Vickers and colleagues are preparing to research possible genetic reasons for this.

“Catalina foxes have an over-exuberant tissue reaction to the same stimuli–the mites–and that appears to lead to the tumors,” Vickers said. “That’s why we gravitate toward genetics in addition to other factors.” The Santa Catalina Island fox is one of six subspecies native to the Channel Islands off the coast of Southern California. Its population declined dramatically in 1999 when a distemper epidemic decimated up to 90 percent of the population, prompting the federal endangered species listing for the roughly 150 foxes remaining. The population has since rebounded to an estimated 1,717 foxes.

http://www.sciencedaily.com/   Science Daily

http://www.sciencedaily.com/releases/2015/12/151207151259.htm  Original web page at Science Daily

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Cougars likely to recolonize middle part of U.S. within the next 25 years

A groundbreaking new study shows that cougars, also known as mountain lions and pumas, are likely to recolonize portions of habitat in the middle part of the United States within the next 25 years. It is the first study to show the potential “when and where” of the repopulation of this controversial large predator.

The study, led by researchers at the University of Minnesota and Southern Illinois University Carbondale, will be published soon in the international journal Ecological Modelling.

This is the first, large-scale population viability study on cougars. The research examined more than 40 years worth of data on demographics and geographical information on more than 3 million square kilometers to determine possible areas of population establishment. The researchers specifically looked at the female dispersal since population settlement is dependent upon the arrival of females in a given area.

“We didn’t just look at where they are now, but where they could go,” said study author Michelle LaRue, a University of Minnesota research associate in the College of Science and Engineering’s Department of Earth Sciences. “These are predictive models, but we feel that our study could be an important tool for conservation of this species and education about a large carnivore that can sometimes incite fear.”

Breeding populations of cougars are already living in the Black Hills of South Dakota, and researchers noted four breeding populations in North Dakota and Nebraska. The new study shows that cougars could be expected in the next two decades in Arkansas, Missouri and Nebraska with the potential to sustain existing populations in the Dakotas and Nebraska.

Historically, cougars were once one of the most widely distributed land mammals on earth, ranging from the Atlantic to Pacific oceans and from northern British Columbia to southern Chile. In the United States, the cougars were pushed back to the American West with the arrival of European settlers. Although they have been extirpated for more than 100 years, cougars have been reported in the middle part of the U.S. over the past two decades with more than 800 instances of confirmed cougar presence from 1990-2015.

“The reason cougars used to exist across the country and now they don’t is because of people,” said study co-author Clayton K. Nielsen from Southern Illinois University Carbondale’s Cooperative Wildlife Research Laboratory and Department of Forestry. “Now that this large carnivore is expected to come back into new areas, we need have a clear plan for education and conservation.”

The next step is to examine human acceptance and attitudes toward the repopulation of cougars, said LaRue, who is also the executive director of the Cougar Network, a non-profit research organization.

“We now have the information necessary for government agencies to plan for ecosystem-based management and societal attitudes toward the recolonization of this predator,” LaRue said. “Given that cougars are expected to inhabit areas where they haven’t been for more than 100 years, this will pose considerable challenges for wildlife managers and the general public in the future.”

http://www.sciencedaily.com/  Science Daily

http://www.sciencedaily.com/releases/2015/11/151106090717.htm  Original web page at Science Daily

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Mating success for the European mink

The European mink (Mustela lutreola) is one of the most endangered mammals in Europe. The reasons for its decline are the destruction of its habitat in riparian areas, competition with the alien American mink and historically, extensive hunting.

The European mink is often confused with the American mink (Neovison vison, previously Mustela vison), which has successfully established itself in Europe as an escapee from fur farms. The larger and more robust American mink has nearly completely replaced the European mink in its previous range.

Species protection projects all over Europe have so far faced the problem that European minks are difficult to breed in zoos. Captivity appears to have a negative effect on breeding success. But captive-bred individuals are needed in order to release and reintroduce the animal into protective zones. “The more we know about the physiology of European minks, the better we can respond to their needs,” says lead author Franz Schwarzenberger from the Institute of Physiology, Pathophysiology and Experimental Endocrinology at the University of Veterinary Medicine, Vienna.

Scientists from the Vetmeduni Vienna, in cooperation with the Endangered Species Research Lab of Tallinn Zoo, collected faecal samples from European mink and analysed them in Vienna. The animals are managed under the aegis of an EEP program (European Endangered Species Program). Female estrus is usually determined by vaginal cytology. The aim of the study was to assess the validity of this method and to optimise diagnosis of ovulation and pregnancy.

“Using our non-invasive method, we were able to measure female estrogen levels and generate a seasonal hormone profile. The results showed that estrogen levels are higher at the time of ovulation. Such estrogen peaks occur three to four times a year on average. The animals are polyestrous. That means, during the breeding season they are fertile in regular intervals. In the past, females which had already been mated with no success were not mated again that same year. Our results reveal that mating can occur much more often,” Schwarzenberger explains.

European minks are solitary animals and extremely territorial in the wild, only approaching each other during the breeding season. In captivity, the animals are housed in large individual enclosures. “The exact time for mating is difficult to determine in a zoo because the animals attack each other if they aren’t receptive. In order to increase the chances of fertilisation, the females are examined at regular intervals during the mating season. During mating, we also closely observe the behaviour of the animals, especially of the males,” explains Astrid Nagl, first author of the study.

The Tallinn Zoo uses vaginal cytology to predict the time of ovulation. This method does not always yield satisfactory results, however. “The data from the fecal analysis serve to augment the available information so that some females which had previously not been mated successfully also had offspring,” Schwarzenberger reports.

The reintroduction of the European mink in Austria would not be easy. “In Austria, the American mink has replaced the European mink in aquatic and riparian zones,” says Schwarzenberger. Releasing the European mink in this habitat would be tantamount to a death sentence, as the American minks would defend their territory and kill the European Mink. This makes reintroduction only possible in areas where no populations of American mink exist,” says Schwarzenberger.

About 100-120 European mink live at Tallinn Zoo. The zoo’s captive-bred animals are reintroduced to the wild on the Estonian islands of Hiiumaa and Saaremaa. Another promising reintroduction project can be found at Steinhuder Meer in northwest Germany.

http://www.sciencedaily.com/  Science Dail

http://www.sciencedaily.com/releases/2015/09/150922114944.htm  Original web page at Science Daily

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Chronic illness causes less harm when carnivores cooperate

Gray wolves in Yellowstone National Park have given researchers the first scientific evidence from wild mammals that living in a group can lessen the impacts of a chronic disease. The research also is one of the first studies to measure the costs of infected non-human individuals of any species on members of their group. Gray wolves in Yellowstone National Park have given researchers the first scientific evidence from wild mammals that living in a group can lessen the impacts of a chronic disease. The research also is one of the first studies to measure the costs of infected non-human individuals of any species on members of their group. A paper describing the research is published in Ecology Letters on May 18, 2015.

“Our research with wolves illustrates that social groups can help to offset the survival costs of infection with the parasite that causes mange,” said Emily Almberg, a research scientist at Penn State University and the lead author of the study. “It suggests that social living might help individuals cope with a variety of other chronic conditions — including other infections, physical injuries, or non-infectious diseases — for which having access to supportive care and resources can make a big difference for survival.”

The study revealed that wolves living alone while infected with mange had a death rate that was five times higher than uninfected wolves living alone. The study also revealed that wolves infected with mange that were living in a pack with at least five other healthy wolves had the same rate of death as their healthy companions. “Our hypothesis is that pack-mates are able to offset the survival costs of infection with mange — and perhaps other infections — by assisting with food acquisition and territory defense,” said Peter Hudson, the senior author of the paper, director of the Huck Institutes of Life Sciences and Willaman Professor of Biology at Penn State, and a professor at the Nelson Mandela Institute in Tanzania.

The research also revealed that the size of the wolf pack did not predict the risk of individuals becoming infected with mange. But, Almberg said, there are other situations in which social living does come with an increased risk of disease transmission. “What we’ve under-appreciated in the past are the ways in which social species might compensate for this increased disease risk,” she said. “In some cases, social species exhibit adaptive behavior to limit the spread of disease — things like defending territories or having distinct social roles within the group that limit contact and therefore disease transmission, but our research has shown that group living can alleviate the actual cost of an infection as measured by survival rates.”

http://www.sciencedaily.com/  Science Daily

http://www.sciencedaily.com/releases/2015/05/150518111854.htm  Original web page at Science Daily

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* Bird flu: New compound protects 100 percent of ferrets, mice, from H5N1

Medical researchers have developed an antibody which has proven 100 percent protective against the H5N1 virus in two species of animal models. Now a team of investigators from St. Jude Children’s Research Hospital, Stanford University Medical Center, and MacroGenics have developed an antibody which has proven 100 percent protective against the virus in two species of animal models. The research is published ahead of print February 11, in the Journal of Virology, a publication of the American Society for Microbiology. Antivirals have been potential sources of protection, but they are hampered by the propensity of viruses to rapidly mutate, which often results in resistance. “We have seen this in H5N1 viruses,” said corresponding author Richard Webby, PhD, a Member in the Infectious Diseases Department at St. Jude Children’s Research Hospital, Memphis, TN, and Director of the World Health Organization (WHO) Collaborating Center for Studies on the Ecology of Influenza Viruses in Lower Animals and Birds.

Vaccines, Webby said, must be developed to match each flu virus, something which would likely take at least six months following the emergence of a pandemic. Additionally, vaccines are somewhat ineffective in the elderly and immunocompromised individuals. The investigators turned to antibodies, which target antigens on viruses as specifically as keys to locks, thus disabling them. Regardless, mutations can render antibodies ineffective. “Our solution was to make a ‘dual-specific’ antibody by combining two different antibodies that attach strongly to H5N1 viruses into a single antibody-like molecule,” said Webby. That, he said, should make it much harder for resistance to emerge. The new compound is called FcDART, for Fc (the type of fusion protein) Dual-Affinity ReTargeting molecule. A single, low dose of the FcDART provided complete protection against lethal H5N1 viruses in laboratory models of influenza. “This dose could be given one day before infection — for example, to protect healthcare providers — or up to three days after,” said Webby. “Laboratory models are rough approximations of what might happen in humans,” said first author Mark Zanin, a post-doctoral fellow in Webby’s lab at St. Jude. “We did see complete protection against H5N1 in ferrets, which have long been used as a model for human flu, so we are confident in our results.”

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http://www.sciencedaily.com/releases/2015/03/150303183405.htm Original web page at Science Daily

 

 

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Odor that smells like blood: Single component powerful trigger for large carnivores

People find the smell of blood unpleasant, but for predatory animals it means food. When behavioural researchers at LinköpingUniversity in Sweden wanted to find out which substances of blood trigger behavioural reactions, they got some unexpected results. Matthias Laska is professor of zoology, specialising in the sense of smell. For some time his focus has been on scents that directly affect the behaviour of animals. “For predators, food scents are particularly attractive, and much of this has to do with blood. We wanted to find out which chemical components create the scent of blood,” he says. The study, conducted at KolmårdenWildlifePark, found that for the animals, one particular component of blood odour was just as engaging as the blood odour itself. “It’s a completely new discovery that raises interesting questions on evolution,” says Prof Laska. The study has been published in the scientific journal PLOS ONE. When Prof Laska did a search for the contents of volatile substances in mammalian blood, he found nothing. Human blood has been analysed for disease markers, but we have very little information on the substances that give blood its characteristic scent. A master’s student was sent to Friedrich-Alexander-Universität in ErlangenGermany, to analyse mammalian blood with the help of gas chromatography and mass spectrometry, methods used for separating and identifying chemical compounds in a sample. The machine detected some 30 substances, of which some are decomposition products from fats. But the machine lost the job to the human scent experts who had also been engaged. They identified scents that the gas chromatograph missed completely. One substance stood out: an aldehyde called trans-4,5-epoxy-(E)-2-decenal, which emits the typical metallic scent that humans associate with blood. Once the researchers had identified a scent candidate that the predators should be attracted to, they wanted to test whether the predators were actually attracted to it in reality. So they designed a study to be conducted at KolmårdenWildlifePark, involving four predator species. How would the four predators — Asian wild dogs, African wild dogs, South American bush dogs and Siberian tigers — react when they caught a whiff of the scent? Half-metre long wooden logs were impregnated with four different liquids: lab-produced aldehyde, horse blood, fruit essence, and a near-odourless solvent. The animals were exposed to one scent per day in their regular enclosure, while a group of students carefully observed their behaviour. The results were unequivocal. The logs containing aldehyde were just as attractive stimuli as those containing blood, while the two other logs aroused little interest. The commonest behaviours were sniffing, licking, biting, pawing and toying. The tiger was the most persistent, while the South American bush dogs lost interest more quickly than the other species.

The study is the first to show that a single component can be just as attractive as the complex odour. “How this has developed through evolution is an interesting question. Perhaps there is a common denominator for all mammalian blood,” says Prof Laska. He has plans for several follow-ups of the study, including how prey animals such as mice react to blood odour. For the wildlife park, the study provided results that can be used in its daily operations. Animals in captivity require stimulation, so as not to deteriorate or become fat. The odourised logs can be a popular addition to the animal’s environment.

http://www.sciencedaily.com/  Science Daily

http://www.sciencedaily.com/releases/2014/11/141110150922.htm Original web page at Science Daily

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Origins of Arctic fox traced back to Tibet

The Arctic fox (Vulpes lagopus) was thought to have evolved in Europe as the ice sheet expanded when a glacial period swept the Earth about 2.6 million years ago. But fossil evidence now suggests that the animal ‘pre-adapted’ to living in the cold and harsh environment on lofty Tibetan terrains. While hiking up and down Tibetan mountains, Xiaoming Wang, a vertebrate palaeontologist at the Natural History Museum of Los Angeles County in California, and his colleagues stumbled on some jawbones and teeth in rocks up to 4,730 metres above sea level. The fossils — unearthed from the Zanda Basin and the Kunlun Pass Basin in the Tibetan Plateau — do not match any of the roughly 20 known fox species, and so represent a new species, Wang and his team report today in Proceedings of the Royal Society B. The team named the species Vulpes qiuzhudingi, in honour of Qiu Zhuding, a prominent palaeontologist at the Chinese Academy of Sciences in Beijing. The first lower molar of the newly identified species has a cutting edge adapted to an all-meat diet, similar to that seen in modern arctic foxes. Most foxes eat both meat and plants. But V. qiuzhudingi‘s teeth are those of an animal that eats mostly meat, and are typical of predators living in extremely cold environments, including polar bears, Arctic foxes and Arctic wolves. “The new Tibetan species and the Arctic fox show striking similarity in their dental adaptation for extreme meat-eating,” says Wang. The specimens were excavated from rocks about 3.6 million to 5.1 million years old. “They are the first Arctic-fox-like fossils to be found from outside the Arctic regions, and they pre-date the oldest records by 3 million to 4 million years,” says Wang. “The scenario seems to be clear that we have an ancestor of Arctic foxes in high Tibet.” Mikael Fortelius, an evolutionary palaeontologist at the University of Helsinki, says that the Arctic fox is just one of several iconic Ice Age animals to have their ancestry traced back to the Tibetan Plateau — other examples being the woolly rhino (Coelodonta thibetana) and the snow leopard (Uncia uncia). The study “lends strong support to the ‘out of Tibet’ hypothesis”, which proposes that animals adapted to a cold, snowy climate in Tibet then spread to other parts of the world as their habitats expanded during ice ages, Fortelius says.

http://www.nature.com/news/index.html  Nature

July 8, 2014

http://www.nature.com/news/origins-of-arctic-fox-traced-back-to-tibet-1.15398  Original web page at Nature

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Study finds recent wolf-dog hybridization in Caucasus region

Dog owners in the Caucasus Mountains of Georgia might want to consider penning up their dogs more often: hybridization of wolves with shepherd dogs might be more common, and more recent, than previously thought, according to a recently published study in the Journal of Heredity. Natia Kopaliani, Dr. David Tarkhnishvili, and colleagues from the Institute of Ecology at Ilia State University in Georgia and from the Tbilisi Zoo in Georgia used a range of genetic techniques to extract and examine DNA taken from wolf and dog fur samples as well as wolf scat and blood samples. They found recent hybrid ancestry in about ten percent of the dogs and wolves sampled. About two to three percent of the sampled wolves and dogs were identified as first-generation hybrids. This included hybridization between wolves and the shepherd dogs used to guard sheep from wolf attacks. The study was undertaken as part of Dr. Kopaliani’s work exploring human-wolf conflict in Georgia. “Since the 2000s, the frequency of wolf depredation on cattle has increased in Georgia, and there were several reports of attacks on humans. Wolves were sighted even in densely populated areas,” she explained. “Reports suggested that, unlike wild wolves, wolf-dog hybrids might lack fear of humans, so we wanted to examine the ancestry of wolves near human settlements to determine if they could be of hybrid origin with free-ranging dogs such as shepherds,” she added. The research team examined maternally-inherited DNA (mitochondrial DNA) and microsatellite markers to study hybridization rates. Microsatellite markers mutate easily, as they do not have any discernible purpose in the genome, and are highly variable even within a single population. For these reasons, they are often used to study hybridization.

“We expected to identify some individuals with hybrid ancestry, but it was quite surprising that recent hybrid ancestry was found in every tenth wolf and every tenth shepherd dog,” said study co-author Tarkhnishvili. “Two dogs out of the 60 or so we studied were inferred to be first generation hybrids,” he added. The study also found that about a third of the dogs sampled shared relatively recent maternal ancestry with local wolves, not with wolves domesticated in the Far East, where most experts believe dogs were first domesticated. The research team used several alternate methods to confirm their results, and came to the same conclusions with each approach. The shepherd dogs studied are a local breed used to guard livestock. “Ironically, their sole function is to protect sheep from wolves or thieves,” Kopaliani explained. “The shepherd dogs are free-ranging, largely outside the tight control of their human masters. They guard the herds from wolves, which are common in the areas where they are used, but it appears that they are also consorting with the enemy.” Wolves at the door: Study finds recent wolf-dog hybridization in Caucasus region Dog owners in the Caucasus Mountains of Georgia might want to consider penning up their dogs more often: hybridization of wolves with shepherd dogs might be more common, and more recent, than previously thought, according to a recently published study in the Journal of Heredity.

http://www.sciencedaily.com/  Science Daily

May 13, 2014

http://www.sciencedaily.com/releases/2014/04/140414092144.htm  Original web page at Science Daily