Tag: Welfare

A species of Indonesian parrot can solve complex mechanical problems that involve undoing a series of locks one after another, revealing new depths to physical intelligence in birds. A team of scientists from Oxford University, the University of Vienna, and the Max Planck Institute, report in PLOS ONE a study in which ten untrained Goffin’s cockatoos (Cacatua goffini) faced a puzzle box showing food (a nut) behind a transparent door secured by a series of five different interlocking devices, each one jamming the next along in the series. To retrieve the nut the birds had to first remove a pin, then a screw, then a bolt, then turn a wheel 90 degrees, and then shift a latch sideways. One bird, called ‘Pipin’, cracked the problem unassisted in less than two hours, and several others did it after being helped either by being presented with the series of locks incrementally or being allowed to watch a skilled partner doing it. The scientists were interested in the birds’ progress towards the solution, and on what they knew once they had solved the full task. The team found that the birds worked determinedly to sort one obstacle after another even though they were only rewarded with the nut once they had solved all five devices. The scientists suggest that the birds seemed to progress as if they employed a ‘cognitive ratchet’ process: once they discovered how to solve one lock they rarely had any difficulties with the same device again. This, the scientists argue, is consistent with the birds having a representation of the goal they were after.

After the cockatoos mastered the entire sequence the scientists investigated whether the birds had learnt how to repeat a sequence of actions or instead responded to the effect of each lock. Dr Alice Auersperg, who led the study at the Goffin Laboratory at Vienna University, said: ‘After they had solved the initial problem, we confronted six subjects with so-called ‘Transfer tasks’ in which some locks were re-ordered, removed, or made non-functional. Statistical analysis showed that they reacted to the changes with immediate sensitivity to the novel situation.’ Professor Alex Kacelnik of Oxford University’s Department of Zoology, a co-author of the study, said: ‘We cannot prove that the birds understand the physical structure of the problem as an adult human would, but we can infer from their behaviour that they are sensitive to how objects act on each other, and that they can learn to progress towards a distant goal without being rewarded step-by-step.’ Dr Auguste von Bayern, another co-author from Oxford University said: ‘The birds’ sudden and often errorless improvement and response to changes indicates pronounced behavioural plasticity and practical memory. We believe that they are aided by species characteristics such as intense curiosity, tactile exploration techniques and persistence: cockatoos explore surrounding objects with their bill, tongue and feet. A purely visual explorer may have never detected that they could move the locks.’ Professor Kacelnik said: ‘It would be too easy to say that the cockatoos understand the problem, but this claim will only be justified when we can reproduce the details of the animals’ response to a large battery of novel physical problems.’

Science Daily
July 23, 2013

Original web page at Science Daily

With an estimated prevalence of 10-15%, feather damaging behaviour (FDB) is a common behavioural disorder in captive parrots (in particular Grey parrots, the species studied in this thesis) that may have aesthetic, medical and welfare consequences and often results in relinquishment or euthanasia. Little evidence-based information, however, is available on the aetiology, associated risk factors, preventive and/or therapeutic interventions. A review of the literature identified many similarities between FDB in parrots, feather pecking in laying hens and trichotillomania in humans and suggested new focus areas for studies into FDB in parrots, which concern both environmental (extrinsic) and animal-bound (intrinsic) factors. First, however, a new feather scoring system was developed for evaluating changes in plumage condition. When compared to an existent feather scoring system, this novel system resulted in higher absolute and relative intra- and inter-observer reliabilities, rendering it useful for monitoring changes in plumage (and FDB) in response to preventive or therapeutic interventions. Environmental enrichment may be an effective tool to reduce FDB. In particular the provision of foraging enrichment is important, as indicated by the presence of contrafreeloading [CFL] in Grey parrots, which demonstrates that parrots are motivated to work for food in presence of free food. The effect of currently available foraging enrichments, however, is too limited to increase foraging times to levels comparable to that of wild conspecifics. These findings emphasize the necessity to develop more effective foraging strategies, but gaining insight into the value of other types of enrichment may be just as important. For this purpose, a closed-economy, two-chamber set-up was designed, which appears promising to establish parrots’ motivation to gain access to different enrichments, thereby allowing for specific recommendations to be made regarding the captive parrot’s living environment. Interestingly, feather damaging parrots were less motivated to work for food compared to healthy individuals, suggesting alterations in their behaviour and ‘needs’. This finding stresses the importance for studies into potential intrinsic factors involved in FDB. Behavioural tests demonstrated that feather damaging parrots display a proactive coping style, suggesting that temperamental traits may play a role in the development of FDB. In addition, neurotransmitters such as serotonin may be involved. To obtain evidence supporting its role, the efficacy of selective serotonin reuptake inhibitors (e.g. paroxetine) in the treatment of FDB may be studied. A pharmacokinetic study helped to establish a dosing regimen (twice daily 4 mg/kg paroxetine HCl dissolved in water, orally) which may subsequently be used in double-blinded, randomised, placebo-controlled clinical trials. The current studies focused on the behaviour and needs of (feather damaging) Grey parrots and laid a basis to further elucidate the role of various intrinsic and extrinsic factors in the onset and maintenance of FDB, and evaluate new therapeutic and preventive interventions that are currently under development.

Full-text at Igitur Archive, Utrecht University
June 25, 2013

Personality is not inherited from birth parents says new research on zebra finches. External factors are likely to play a bigger part in developing the personality of an individual than the genes it inherits from its parents, suggests the study. Researchers at the University of Exeter and the University of Hamburg investigated how personality is transferred between generations. They found that foster parents have a greater influence on the personalities of fostered offspring than the genes inherited from birth parents. Dr Nick Royle from Biosciences at the University of Exeter said: “This is one of the first experiments to show that behaviour can be non-genetically transmitted from parents to offspring. Our study shows that in zebra finches, personality traits can be transmitted from one generation to another through behaviour not just genetics.” The research, published in the journal Biology Letters, measured personality by placing the zebra finches in a new environment and counting the number of features they visited. Some were shy, staying mainly in one place while others explored widely demonstrating a more outgoing personality. Male and female birds were then paired up and allowed to breed. Each clutch of eggs was fostered by another pair just prior to hatching. Offspring personality was measured once they were adults. Offspring size was also measured and was found to be primarily genetically inherited and not significantly influenced by foster parent size.

Although this study considers personality inheritance in zebra finches, it raises questions about the inheritance of personality in other species, including humans. Do adopted children inherit the personality characteristics of their birth parents or their adoptive parents? Is the environment more important than genetic inheritance in the development of personality? The results of this study indicate that non-genetic transmission of behaviour can play an important role in shaping animal personality. Further studies will build on this research to assess how widespread behavioural inheritance is for personality traits across other species.

Science Daily
June 25, 2013

Original web page at Science Daily

Researchers from the Seoul National University found that wild birds appear to “think faster” when humans, and possibly predators in general, are directly looking at them. “We started this study from our experience” says Dr. Sang-im Lee, the leader of magpie research team and the first author of the paper. “For a long time we had this impression that somehow magpies know that we are watching them because they often fly away from us when we observe them. But when we don’t observe them, we can pass them pretty close-by but they don’t fly away!” The finding that animals notice the gaze of humans is not new. Usually animals use gaze of the conspecifics in social contexts and therefore pet animals pay attention to the gaze of humans — their social mates. Also in the case of predator and prey interactions it is well known that animals such like birds, lizards or deer move away or escape from humans at larger distances when people look directly at them. In these situations it was believed that animals react at larger distance and sooner because the gaze is an indicator to the prey that the predator “wants to catch it.” Therefore, when a prey notices the gaze of a predator it moves away from the predator in order to increase safety. Not surprisingly, the researchers found that magpies on the campus of the Seoul National University also flew away at larger distances when humans were directly looking at them.

But this is not the most important finding of this research. When researchers, who were approaching foraging magpies, looked directly at the magpies, the magpies took the decisions faster regardless of whether the final decision was to return to foraging or to fly away and whether the stress or danger perceived by a magpie was low or high. But when the approaching pair of humans did not look at the magpies, the decision to escape or not was taken with a delay. In other words even if the magpies did not perceive the humans as dangerous they still took the decision faster (in this case decision to stay and continue foraging) when the humans were looking at them. This is consistent with the idea that the birds are able to extract more information for their quick decisions from people’s faces and/or gaze direction regardless of what kind of information they get. Magpies have lived near humans for centuries or even millenia and such skills might have been important for their survival.

Science Daily
June 25, 2013

Original web page at Science Daily

Unlike their urban counterparts, forest-dwelling blackbirds rise with the Sun. Just as city slickers have faster-paced lives than country folk, so too do urban birds, compared with their forest-dwelling cousins. The reason, researchers report today, is that urban noise and light have altered the city birds’ biological clocks. The finding helps to explain prior reports that urban songbirds adopt more nocturnal lifestyles data that prompted Davide Dominoni, an ecologist at the Max Planck Institute for Ornithology in Radolfzell, Germany, to investigate whether the birds’ activity patterns were merely behavioural responses to busy cities or were caused by an actual shift in the animals’ body clocks. For the study, published in Proceedings of the Royal Society B, Dominoni and his colleagues set up an experiment with European blackbirds (Turdus merula). The scientists attached tiny 2.2-gram radio-pulse transmitters to blackbirds living in Munich, Germany, as well as to those living in a nearby forest. The transmitters monitored the birds’ activity for three weeks. Dominoni found that whereas forest birds started their activity at dawn, city birds began 29 minutes earlier, on average, and remained active for 6 minutes longer in the evening.

Keen to determine these differences were due to physiological changes, Dominoni collected blackbirds from both locations and placed them into light- and sound-proof enclosures. For ten days these enclosures were illuminated with a constant, dim light so the birds had no idea what time of day it was, and their activity patterns were monitored. The researchers found that the city birds in the enclosures had faster biological clocks than forest birds. It took the city birds an average of 50 minutes less to go through a full 24-hour cycle of activity than it took forest birds. And without the external stimuli of dawn and dusk, the urban birds’ behavioural rhythms weakened rapidly, with their periods of activity and rest becoming more irregular than those of the forest birds. Having such weakly set biological clocks could be a boon for the blackbirds. “It could make them better at coping with city environments that are not as predictable as the wilderness,” says Dominoni. But such clocks could also potentially have adverse health effects. “You have to wonder — if these city birds are not compensating by napping during the day or sleeping more deeply at night, is sleep deprivation reducing their cognitive abilities or shortening their life spans?” says Niels Rattenborg, an avian sleep biologist at the Max Planck Institute for Ornithology in Seewiesen, who was not associated with the study.

Nature
June 25, 2013

Original web page at Science Daily

Go to about any public square, and you see pigeons pecking at the ground, always in search of crumbs dropped by a passerby. While the pigeons’ scavenging may seem random, new research by psychologists at the University of Iowa suggest the birds are capable of making highly intelligent choices, sometimes with problem-solving skills to match. The study by Edward Wasserman and colleagues centered on the “string task,” a longstanding, standard test of intelligence that involves attaching a treat to one of two strings and seeing if the participant (human or animal) can reel in that treat by pulling the correct string. In this case, the UI researchers took the pigeons into the digital age: The birds looked at a computer touch screen with square buttons connected to either dishes that appeared to be full or empty. If the bird pecked the correct button on the screen, the virtual full bowl would move closer, ultimately to the point where the pigeon would be rewarded with real food. “The pigeons proved that they could indeed learn this task with a variety of different string configurations—even those that involved crossed strings, the most difficult of all configurations to learn with real strings,” says Wasserman, Stuit Professor of Experimental Psychology and the corresponding author of the study published in the journal Animal Cognition.

In experiments, the authors found the pigeons chose correctly between 74 percent and 90 percent of the time across three varieties of string tests. The breadth of the string tests, coupled with the pigeons’ accuracy, suggest that virtual string tests can be used in place of conventional string experiments—and with other animal species as well, the researchers say. In videos that the researchers took, the pigeons in many instances scan and bob their heads along the string “often looking toward and pecking at the dish as its moves down the screen,” the authors write, suggesting the birds noted the connection between the virtual strings and the dishes. “We believe that our virtual string task represents a promising innovation in comparative and developmental psychology,” Wasserman says. “It may permit expanded exploration of other species and variables which would otherwise be unlikely because of inadequacies of conventional string task methodology or sensorimotor limitations of the organisms.” “These results not only testify to the power and versatility of our computerized string task, but they also demonstrate that pigeons can concurrently contend with a broad range of demanding patterned-string problems, thereby eliminating many alternative interpretations of their behavior,” the authors write. The paper is titled, “Pigeons learn virtual patterned-string problems in a computerized touch screen environment” and was first published online in March. The UI psychology department funded the study.

EurekAlert! Medicine
June 11, 2013

Original web page at EurekAlert! Medicine

Like many birds, penguins must travel a long way between their feeding and breeding grounds. But rather than fly, they swim. It is a hard journey that has left biologists scratching their heads over why the birds did not keep their ability to fly as their diving ability evolved. A new study argues that birds cannot be both masterful divers and flyers, because flying abilities must weaken as the animals adapt to diving. Rather than looking at penguins, a team led by biologist Kyle Elliott at the University of Manitoba in Winnipeg, Canada, examined species of diving seabirds that still have some ability to fly. These included the pelagic cormorant (Phalacrocorax pelagicus), a species that propels itself underwater with webbed feet, and the thick-billed murre (Uria lomvia), which flaps its wings underwater to swim. The researchers tagged murres with recorders that measured the time of dives as well as depth and temperature, and cormorants with data-loggers that measured depth, temperature and acceleration changes during dives. They also injected isotope-tagged water into the birds. When the researchers tested the birds later, the tags enabled them to work out just how much carbon dioxide and water vapour the birds had expelled since the water was introduced, and thus to calculate the energy expended for diving and flying.

The team then compared their results to some that had already been collected for birds such as geese and penguins. They found that both cormorants and murres must spend exceedingly large amounts of energy to fly — the highest known among all flying birds. When it came to diving, the energy costs for the foot-propelled cormorants were much higher than expected for a similarly sized penguin. The wing-propelled murres had diving costs lower than those of cormorants, but still 30% greater than those experienced by penguins of the same size. The results appear in the Proceedings of the National Academy of Sciences. The findings reveal a snapshot showing that murres are sitting on an evolutionary knife edge. Elliott and his colleagues speculate that because the wings of a murre are still built for flight, they create drag underwater. Furthermore, their small bodies, which are just light enough for them to take off, cool down more quickly than the bulkier bodies of penguins. “Basically, they have to reduce their wings or grow larger to improve their diving, and both would make flying impossible,” says Robert Ricklefs, an ornithologist at the University of Missouri–St. Louis and co-author of the paper. Yet questions remain over just how much the birds’ energy costs are related to inefficient flying and swimming, and how much they are related to staying warm.

“The problem here is that the murres and cormorants lose heat in very different ways,” says ornithologist Rory Wilson of Swansea University, UK. “Murres carry a lot of air in their feathers and emerge from dives dry, while cormorant feathers get soggy,” he says. Wilson adds that cormorants may actually be reasonably efficient flyers but seem inefficient in this study because they are using a lot of energy to cope with cold wind blasting their wet bodies. Others agree with Elliott’s team. “It is great to so clearly see that flight is sacrificed for improved diving ability,” says James Lovvorn, an ornithologist at Southern Illinois University in Carbondale. “Now what we really need is an experiment that specifically takes the costs of staying warm into consideration.”

Nature
June 11, 2013

Original web page at Nature

Study suggests swallows and martins breed indoors and close to humans to avoid having to rear cuckoos. Some species of birds reproduce not by rearing their own young, but by handing that task on to adults of other species. Known as brood parasitism, this habit has been most thoroughly researched in the cuckoo. Previous research has found, however, that the nests of martins and swallows in Europe are rarely parasitized by cuckoos. A new study by Wen Liang from the Hainan Normal University in China and his colleagues suggests that swallows build their nests close to humans to reduce their susceptibility to brood parasitism. The findings are published in Springer’s journal Behavioral Ecology and Sociobiology. When a cuckoo egg is placed in a host nest, the host may either recognize that the egg is not one of its own and eject it from the nest, or it incubates and hatches the cuckoo egg. If the cuckoo egg hatches, the fledgling will usually push any other eggs and nestlings it encounters over the edge of the nest. Once the host parents are deprived of their rightful young, they devote all their time and energy to feeding the young cuckoo.

Cuckoos tend not to inhabit villages, towns and cities and prefer to nest in open areas. The researchers suggest that the low rates of brood parasitism of swallows and martins in Europe could be caused by these birds now breeding in close association with humans and building their nests inside buildings. The barn swallow in China still nests predominantly outside but, interestingly, has low rates of parasitism by cuckoos. In order to fully investigate the reasons for this, the researchers placed model mimetic eggs in the nests of barn swallows, house martins and red-rumped swallows. They noted that the rate of rejection of model cuckoo eggs was much higher in the birds with nests located outdoors than in the indoor nests. The authors contend that in order to avoid brood parasitism by cuckoos, European martins and swallows have over the years evolved to build their nests inside and in places inaccessible to cuckoos. These birds therefore are less “skillful” in ejecting the mimic cuckoo eggs from their nests. As barn swallows in China still build nests outside and therefore are more susceptible to brood parasitism, they are better able to assess when an egg is not theirs and remove the foreign egg from their nest quickly. This shows that they have been able to develop an alternative strategy to reduce the likelihood of cuckoo parasitism. The authors conclude that “suitable cuckoo hosts breeding close to human habitation enjoy a selective advantage from breeding indoors in terms of reduced risk of parasitism. Cuckoos are more likely to parasitize barn swallow nests outdoors than indoors. These findings suggest that birds benefit from association with humans in terms of reduce risk of parasitism.”

Science Daily
April 29, 2013

Original web page at Science Daily

In a collaborative study published online in Nature Genetics, researchers from Cardiff University, BGI, International Wildlife Consultants, Ltd., and Abu Dhabi Falcon Hospital, have completed the genome sequencing and analysis of two iconic falcons, the peregrine (Falco peregrinus) and saker (Falco cherrug). The work provides an invaluable resource for the deep understanding of the adaptive evolution in raptors and the genetic basis of their wide distribution. Peregrine and saker falcons are widespread, and their unique morphological, physiological and behavioral adaptations make them successful hunters. The peregrine is renowned as the world’s fastest animal, and the falcon is the national emblem of United Arab Emirate. In recent decades, peregrine and saker falcons have been listed as endangered due to rapid population declines caused by a wide range of factors including environmental change, overharvesting for falconry, habitat loss and bioaccumulation of pesticides (e.g. DDT, PCBs). In this study, researchers focused on the evolutionary basis of predatory adaptations underlying peregrine and saker. They conducted whole genome sequencing and assembled the high quality ~1.2 Gb reference genomes for each falcon species. Phylogenic analysis suggested that the two falcon species might diverged 2.1 million years ago.

Comparing with chicken and zebra finch, researchers found the transposable element composition of falcons was most similar to that of zebra finch. Large segmental duplications in falcons are less frequent than that in chicken and zebra finch, and comprise less than 1% of both falcon genomes. They also found that a gene expansion in the olfactory receptor γ-c clade in chicken and zebra finch is not present in falcons, possibly reflecting their reliance on vision for locating prey. Observing genome-wide rapid evolution for both falcons, chicken, zebra finch and turkey, researchers found that the nervous system, olfaction and sodium ion trans-port have evolved rapidly in falcons, and also the evolutionary novelties in beak development related genes of falcons and saker-unique arid-adaptation related genes. Shengkai Pan, bioinformatics expert from BGI, said, “The two falcon genomes are the first predatory bird genome published. The data presented in this study will advance our understanding of the adaptive evolution of raptors as well as aid the conservation of endangered falcon species.”

Science Daily
April 16, 2013

Original web page at Science Daily

Alice Auersperg from the Department of Cognitive Biology from the University of Vienna and her team has for the first time succeeded in observing self-control in cockatoos. The results of this research project appear in the current issue of the journal Biology Letters. In the 1970’s, self-control of human infants was investigated using the prominent ‘Stanford Marshmallow Experiment’: the children were presented with a marshmallow and were told they could either eat it now or wait and receive a second one if the first one was still intact after a time delay of several minutes. Interestingly, children that were able to wait for the delayed reward showed greater success in adult life than the ones that ate the first marshmallow right away. The ability to anticipate a delayed gain is considered cognitively challenging since it requires not only the capacity to control an direct impulse but also to assess the gain’s beneficial value relative to the costs associated with having to wait as well as the reliability of the trader. Such abilities can be considered precursors of economic decision making and are rarely found outside humans.

Only few, typically large-brained animals, have been shown to be able to inhibit the consumption of an immediate food reward in anticipation for a bigger one for more than one minute. A new study at the University of Vienna, on an Indonesian cockatoo species — the Goffin’s cockatoo — showed notable results. “The animals were allowed to pick up an initial food item and given the opportunity to return it directly into the experimenter’s hand after an increasing time delay. If the initial food item had not been nibbled by this time, the bird received another reward of an even higher preferred food type or of a larger quantity than the initial food in exchange” explains Isabelle Laumer, who conducted the study at the Goffin Lab at the University of Vienna. “Although we picked pecan nuts as initial reward which were highly liked by the birds and would under normal circumstances be consumed straight away, we found that all 14 of birds waited for food of higher quality, such as cashew nut for up to 80 seconds,” she further reports.

Alice Auersperg, the manager of the Vienna Goffin Lab says: “When exchanging for better qualities, the Goffins acted astonishingly like economic agents, flexibly trading-off between immediate and future benefits. They did so, relative not only to the length of delay, but also to the difference in trade value between the ‘currency’ and the ‘merchandise’: they tended to trade their initial items more often for their most preferred food, than for one of intermediate preference value and did not exchange in a control test in which the value of the initial item was higher than that of the expected one.” She adds: “While human infants or primates can hold the initial food in their hands, one should also consider that the birds were able to wait, although they had to hold the food in their beaks, directly against their taste organs while waiting. Imagine placing a cookie directly into a toddler’s mouth and telling him/her, he/she will only receive a piece of chocolate if the cookie is not nibbled for over a minute.” Thomas Bugnyar, who previously conducted similar studies on ravens and crows, says, “Until recently, birds were considered to lack any self-control. When we found that corvids could wait for delayed food, we speculated which socio-ecological conditions could favor the evolution of such skills. To test our ideas we needed clever birds that are distantly related to corvids. Parrots were the obvious choice and the results on Goffins show that we are on the right track.”

Science Daily
April 2, 2013

Original web page at Science Daily

Since the advent of highways, cliff swallows have built nests that hang off bridges and tunnels, putting them in close proximity to traffic. Cliff swallows that build nests that dangle precariously from highway overpasses have a lower chance of becoming roadkill than in years past thanks to a shorter wingspan that lets them dodge oncoming traffic. That’s the conclusion of a new study based on 3 decades of data collected on one population of the birds. The results suggest that shorter wingspan has been selected for over this time period because of the evolutionary pressure put on the population by cars. “This is a clear example of how you can observe natural selection over short time periods,” says ecologist Charles Brown of the University of Tulsa in Oklahoma, who conducted the new study with wife Mary Bomberger Brown, an ornithologist at the University of Nebraska, Lincoln. “Over 30 years, you can see these birds being selected for their ability to avoid cars.”

The Browns have studied cliff swallows (Petrochelidon pyrrhonota) in southwestern Nebraska since 1982. They return to the same roads every nesting season to perform detailed surveys of the colonies of thousands of birds that build mud nests on bridges and overpasses in the area. Along with studies on living swallows—counting birds and eggs, netting and banding individuals, and observing behaviors—the Browns also picked up swallow carcasses they found on the roads, in the hopes of having additional specimens to measure and preserve. They hadn’t planned studies on roadkill numbers, but recently they began to get the sense that they were picking up fewer dead birds than in the past. When the researchers looked back at the numbers of swallows collected as roadkill each year, they found that the count had steadily declined from 20 birds a season in 1984 and 1985 to less than five per season for each of the past 5 years. During that same time, the number of nests and birds had more than doubled, and the amount of traffic in the area had remained steady. The birds that were being killed, further analysis revealed, weren’t representative of the rest of the population. On average, they had longer wings. In 2012, for example, the average cliff swallow in the population had a 106-millimeter wingspan, whereas the average swallow killed on the road had a 112-millimeter wingspan.

“Probably the most important effect of a shorter wing is that it allows the birds to turn more quickly,” says Charles Brown. Previous studies on the dynamics of flight have illustrated the benefits of short wings for birds that perform many pivots and rolls during flying and shown that shorter wings also may allow the birds to take off faster from the ground, he adds. When the researchers analyzed the average wing length of the living birds in the population, they discovered that it had become shorter over time, from 111 millimeters in 1982 to the 106 millimeter average in 2012. The data suggested to the Browns that roadkill deaths were a major force driving this selection. Birds with longer wings would be more likely to be killed by vehicles and less likely to reproduce, the team reported online recently in Current Biology. The data illustrate a “beautiful trend that never could have been predicted,” says evolutionary biologist John Hoogland of the University of Maryland Center for Environmental Science in Frostburg, who was not involved in the study. “We humans, because we’re changing the environment so much, are adding a new kind of natural selection to these animal populations.” Few studies have looked at long-term changes in roadkill numbers, Charles Brown says, so more work is needed to determine whether similar trends hold for swallows in other areas, for other types of birds, or for mammals. “I would think that this would be a pattern that certainly might apply to other species,” he says. “But there’s almost nothing in the literature on historical trends in roadkills, because surveys typically last a season or two, not an extended period of years.” The new findings could also apply to birds killed by wind turbines, Hoogland adds, and they illustrate the payoff that can come with careful data collection and observation. “I think the most important lesson from this research is the paramount importance of collecting data even when you’re not sure what it means or how it could lead to findings in the future.”

ScienceNow
April 2, 2013

Original web page at ScienceNow