Parasite may create risk-taking wolves in Yellowstone

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THE UNIVERSITY OF MONTANA

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IMAGE: UNIVERSITY OF MONTANA DOCTORAL STUDENT CONNOR MEYER, SHOWN HERE WITH A WOLF SKULL IN UM’S ZOOLOGICAL MUSEUM, STUDIES THE EFFECTS OF A PARASITE ON WOLVES IN YELLOWSTONE NATIONAL PARK. view more 

CREDIT: UNIVERSITY OF MONTANA PHOTO BY TOMMY MARTINO

MISSOULA – New research from a University of Montana student and his partners suggests that a common parasite associated with cats turns Yellowstone National Park wolves into risk takers, who when infected are much more likely to disperse across the landscape and become pack leaders.

The story caught fire with media outlets worldwide, with both CNN and NPR picking it up. The research originally was published in the journal Communications Biology.

“I’ve been blown away by it,” said Connor Meyer, a wildlife biology doctoral student in UM’s Ungulate Ecology Lab, part of the W.A. Franke College of Forestry & Conservation. “I’m surprised and grateful, but it’s been a bit of a nerve-wracking experience with all the attention.”

Meyer and his team created the story sensation by studying a single-celled creature named Toxoplasma gondii – often nicknamed the “mind-control parasite.” It prefers to live in felines, and infected cats spread spore-packed oocysts in their feces. T. gondii – which Meyer calls “toxo” for short – is the reason pregnant people aren’t supposed to clean the litterbox. Human immune systems usually keep it in check, but the parasite causes sickness that can be dangerous to fetuses, as well as those who are immunocompromised, such as HIV/AIDS patients.

T. gondii can infect all warm-blooded mammals, and it’s estimated a third of all people are carriers. The parasite settles in muscles and brains, and it’s known to boost dopamine and testosterone. This affects behavior: Studies have shown that infected rodents lose their fear of feline urine or cats and move around in the open more, making them more likely to be eaten. Infected captive chimpanzees lose their aversion to leopard urine.

It’s almost like they are being biologically controlled so the parasite can return to the comfy insides of its preferred feline host. But do other beasts get affected that aren’t part of the regular T. gondii life cycle?

Meyer and his fellow lead author, Yellowstone park biologist Kira Cassidy, started a serious study of the prevalence of T. gondii among park wolves in spring 2021. They discovered a toxo-positive wolf becomes more of a risk taker – 11 times more likely to disperse from its original pack and 46 times more likely to become a pack leader.

Yellowstone wolves are among the most studied animals in the world. Since they were reintroduced in 1995, park managers have taken blood samples every time a wolf is captured and collared. Meyer and his team wound up testing blood from 243 wolves for toxo antibodies with assistance from a Cornell University diagnostics lab. They also used data from long-term and ongoing Yellowstone Wolf Project research. More than 27% of the wolves they looked at – about 74 individuals all told – were infected with T. gondii.

The researchers first suspected wolves were getting infected by eating elk, their chief prey. But when they tested more than 100 elk, none were positive for the parasite.

“Eventually we found the most significant predictor of infection with wolves was when their range overlapped areas with high mountain lion density,” Meyer said. “So, with no elk testing positive, we hypothesized they were getting infected directly by cougars.”

Yellowstone wolves can slay and eat mountain lions, but there only have been 10 or so documented cases of that since 1995. Meyer said it’s more likely wolves they get toxo infection by nosing around “scrape sites,” where cougars defecate and mark their territory.

“We also have a litter box theory,” he said. “Almost anyone who has a dog and cat at home knows that, if the dog gets an opportunity, they are going to raid the litter box. We don’t have direct evidence of wolves eating mountain lion scat, but we have lots of photos of wolves at mountain lion scrapes. Wolves eat lots of things, so we don’t think it’s much of a stretch.”

Meyer said they want to emphasize they aren’t claiming that toxo causes wolves to become leaders.

“Toxo is not the only factor that predicts whether wolves will lead the pack,” he said. “It’s one of the many things that affect wolf behavior, just like in humans. With our study, being toxo-positive shortened the time it took for individuals to disperse, but toxo-negative individuals would still disperse and still become pack leaders. So we aren’t saying that toxo runs the world – we are saying it may accelerate some of these behaviors.”

He also said wolf packs generally have two leaders, a male and a female, and both are equally likely to test positive for the parasite.

A native of Whidbey Island, Washington, Meyer first became fascinated by the T. gondii life cycle as an undergraduate at the University of Washington. He then was hired by Dr. Matthew Metz – who earned his Ph.D. from UM last year – to work for the Yellowstone Wolf Project and soon after also began work with the Yellowstone Cougar Project. Over six years he worked on a variety of research efforts, which brought him into the orbit of Professor Mark Hebblewhite, leader of UM’s Ungulate Ecology Lab. Meyer started making inquiries about grad school.

“UM is one of the best – if not the best – wildlife biology graduate schools in the nation,” Meyer said, “so I definitely had an interest in coming here. Mark said working on the toxo paper could help me get into his program. I started at UM in 2021, working with Mark on an elk migration study in Canada. Doing this paper gave me a little more confidence as I jumped straight into a super-intense Ph.D. program.”

Though Meyer believes stories about T. gondii may be getting a bit sensationalized, and that too much may be attributed to its supposed mind-bending powers, he said we need to learn more about the parasite. Studies suggest that humans infected with toxo are more likely to like cats, develop schizophrenia or engage in road rage. He said a recent study on a college campus found students infected with toxo generally were rated more attractive.

Is it messing with our minds?

“More work definitely needs to be done,” Meyer said. “Luckily for us with our study, we had all that excellent data, we had all the blood serum and we had the time, interest and encouragement to check it out.”

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Disease outbreaks influence the color of wolves across North America

 New research from the University of Oxford, Yellowstone National Park, and Penn State, published today in the journal Science, may have finally solved why wolves change colour across the North American continent.

If you were to travel from Arctic Canada and head south down the Rocky Mountains into the US toward Mexico, the further south you go, the more black wolves there are. The reasons why have long puzzled scientists.

Professor Tim Coulson from the Department of Biology, University of Oxford who led the work explains, ‘In most parts of the world black wolves are absent or very rare, yet in North America they are common in some areas and absent in others. Scientists have long wondered why. We now have an explanation based on wolf surveys across North America, and modelling motivated by extraordinary data collected by co-authors who work in Yellowstone.’

Coat colour in wolves (Canis lupus) is determined by a gene called CPD103. Depending on the variant of the gene a wolf has, its coat can either be black or grey.

The researchers postulated that this gene also plays a role in protecting against respiratory diseases such as canine distemper virus (CDV). This is because the DNA region containing the gene also encodes for a protein that plays a role in defending against infections in the lungs of mammals. They predicted that having a black coat would be associated with the ability of wolves to survive an infection with CDV.

To test this idea, they analysed 12 wolf populations from North America, to examine whether the probability of a wolf being black was predicted by the presence of CDV antibodies. If a wolf has CDV antibodies, then it has caught CDV in the past and survived. They found that wolves with CDV antibodies were more likely to be black than grey. They also found that black wolves were more common in areas where CDV outbreaks occurred.

The researchers analysed over 20 years-worth of data from the wolf population at Yellowstone National Park. They found that black wolves were more likely to survive CDV outbreaks compared with grey wolves. These results led them to hypothesise that in areas where distemper outbreaks occur wolves should choose mates of the opposite coat colour to maximize the chance their cubs would have black coats.

They used a simple mathematical model to test this idea. Excitingly, the predictions from their model closely matched the observations that black and grey wolves were more likely to pair in areas where CDV outbreaks are common. This competitive advantage is lost in areas where CDV outbreaks do not occur.

These results are consistent with the idea that the frequency of CDV outbreaks across North America is responsible for the distribution of black wolves, because having the gene for a black coat may also provide protection against the virus. It also explains why mating pairs in Yellowstone, where canine distemper outbreaks occur, tend to be black-grey.

Peter Hudson, Willaman Professor of Biology, Penn State said ‘It’s intriguing that the gene for protection against CDV came from domestic dogs brought by the first humans entering North America, and the CDV disease virus emerged in North America many thousands of years later, once again from dogs.’

‘What I love about this study is how we have been able to bring together experts from so many fields and a range of approaches to show how disease can have remarkable impacts on wolf morphology and behaviour. We are learning that disease is a major evolutionary driver that impacts so many aspect aspects of animal populations.’

The researchers speculate that other species may follow a similar pattern to wolves. Many insects, amphibians, birds and nonhuman mammals have associations between colour and disease resistance. It might be that the presence a disease, or how frequently a disease outbreak occurs, is an important factor affecting the colour of mate an animal prefers.

Isle Royale Winter Study finds wolves living their best lives, moose not so much

 

IMAGE: TWO PUPS FROM THE EASTERN PACK TRY TO ROUSE PACKMATES FOR PLAY. view more 

CREDIT: SARAH HOY

Key findings include:

• A doubling of the wolf population, now estimated at 28 total wolves. “Each time we carried out aerial surveys this winter, we saw wolf tracks across many parts of the island and we also regularly saw groups of wolves traveling or resting together,” said Hoy. “It is such a pleasant change from five years ago when there were only two wolves on the island and the future of the wolf population looked pretty bleak. It just goes to show how quickly wolf populations are able to thrive in places where they are free from persecution.”

• A 28% decline in the moose population, from 1,876 to 1,346. Wolf kills accounted for 8.7% of the moose mortalities, the highest predation rate since 2011. Other challenges for the moose include blood-sucking winter ticks that weaken the animals, and spruce budworm infestations that kill balsam fir, their preferred winter food. “Over the past year we found an unusually high number of moose that appear to have died due to malnutrition,” Hoy said. “The population appears to be suffering from a food shortage, especially in winter when moose don’t have many good options of things to eat.”

For more information and to access the Winter Study report, read the full story at MTU News.

More wolves, beavers needed as part of improving western United States habitats, scientists say

 Oregon State University scientists are proposing management changes on western federal lands that they say would result in more wolves and beavers and would re-establish ecological processes.

In a paper published today in BioScience, “Rewilding the American West,” co-lead author William Ripple and 19 other authors suggest using portions of federal lands in 11 states to establish a network based on potential habitat for the gray wolf – an apex predator able to trigger powerful, widespread ecological effects.

In those states the authors identified areas, each at least 5,000 square kilometers, of contiguous, federally managed lands containing prime wolf habitat. The states in the proposed Western Rewilding Network, which would cover nearly 500,000 square kilometers, are Oregon, Washington, California, Nevada, Idaho, Montana, Wyoming, Colorado, Arizona, New Mexico and Utah.

“It’s an ambitious idea, but the American West is going through an unprecedented period of converging crises including extended drought and water scarcity, extreme heat waves, massive fires and loss of biodiversity,” said Ripple, distinguished professor of ecology in the OSU College of Forestry.

Gray wolves were hunted to near extinction in the West but were reintroduced to parts of the northern Rocky Mountains and the Southwest starting in the 1990s through measures made possible by the Endangered Species Act.

“Still, the gray wolf’s current range in those 11 states is only about 14% of its historical range,” said co-lead author Christopher Wolf, a postdoctoral scholar in the College of Forestry. “They probably once numbered in the tens of thousands, but today there might only be 3,500 wolves across the entire West.”

Beaver populations, once robust across the West, declined roughly 90% after settler colonialism and are now nonexistent in many streams, meaning ecosystem services are going unprovided, the authors say.

By felling trees and shrubs and constructing dams, beavers enrich fish habitat, increase water and sediment retention, maintain water flows during drought, improve water quality, increase carbon

sequestration and generally improve habitat for riparian plant and animal species.

“Beaver restoration is a cost-effective way to repair degraded riparian areas,” said co-author Robert Beschta, professor emeritus in the OSU College of Forestry. “Riparian areas occupy less than 2% of the land in the West but provide habitat for up to 70% of wildlife species.”

Similarly, wolf restoration offers significant ecological benefits by helping to naturally control native ungulates such as elk, according to the authors. They say wolves facilitate regrowth of vegetation species such as aspen, which supports diverse plant and animal communities and is declining in the West.

The paper includes a catalogue of 92 threatened and endangered plant and animal species that have at least 10% of their ranges within the proposed Western Rewilding Network; for each species, threats from human activity were analyzed.

The authors determined the most common threat was livestock grazing, which they say can cause stream and wetland degradation, affect fire regimes and make it harder for woody species, especially willow, to regenerate.

Nationally, about 2% of meat production results from federal grazing permits, the paper notes.

“We suggest the removal of grazing on federal allotments from approximately 285,000 square kilometers within the rewilding network, representing 29% of the total 985,000 square kilometers of federal lands in the 11 western states that are annually grazed,” Beschta said. “That means we need an economically and socially just federal compensation program for those who give up their grazing permits. Rewilding will be most effective when participation concerns for all stakeholders are considered, including Indigenous people and their governments.”

In addition to Beschta, Wolf and Ripple, authors from Oregon State include J. Boone Kauffman, Beverly Law and Michael Paul Nelson. Daniel Ashe, former director of the U.S. Fish and Wildlife Service and now the president of the Association of Zoos and Aquariums, is also a co-author.

The paper also included authors from the University of Washington, the University of Colorado, the Ohio State University, Virginia Tech, Michigan Technological University, the University of Victoria, the Turner Endangered Species Fund, the National Parks and Conservation Association, RESOLVE, the Florida Institute for Conservation Science, Public Lands Media and Wild Heritage.

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JOURNAL

BioScience

DOI

10.1093/biosci/biac069 

Bring back the wolves – but not as heroes or villains

 

- In a new finding that goes against current conservation paradigms, re-introducing wolves and other predators to our landscapes does not miraculously reduce deer populations, restore degraded ecosystems or significantly threaten livestock, according to a new study.

“The hopes and fears that we have on both sides of the debate – neither are realized. That doesn’t mean we shouldn’t allow the wolves, the mountain lions, to return to their traditional landscapes – they’re a part of it,” said conservation biologist Bernd Blossey, professor of natural resources and the environment at Cornell University. Blossey is lead author of “Myths, Wishful Thinking, and Accountability in Predator Conservation and Management in the United States,” published June 3 in Frontiers in Conservation Science. His co-author is Darragh Hare of Oxford University.

“Based on the currently available evidence (not just from the United States) large predators, despite their ability to kill ungulates and livestock, will not eliminate deer, threaten people or lead to intolerable losses of livestock – the myths,” the authors write. “On the other hand, large predators are unlikely to right all wrongs humans have inflicted on ecosystems – the wishful thinking.”

On the myths side, there is little evidence for claims that re-introducing large predators such as wolves, bears and mountain lions is a major threat to livestock and wild ungulates such as white-tailed deer, mule deer and elk.

When the U.S. federal government took the wolf off the endangered species list, hunters and livestock producers, and some state governments, called for action combatting what they saw as a need to safeguard the wildlife they wanted to hunt and the livestock that was their livelihood.

But it is nearly impossible to independently evaluate those claims, Blossey said. Other factors also kill livestock, from lightning strikes to hot or and cold weather, parasites, diseases, and poor husbandry and foraging conditions. And there’s much that livestock producers can do to protect their animals from predators, such as deploying more staff, guard dogs and fencing.

And hunters don’t need to worry about wolves competing for deer. The U.S. deer population is at an historic high, in part because humans have given them ideal living conditions and plenty of food. “What we do to landscapes, whether that’s forestry, agriculture or gardening, provide deer with a perfect landscape for them to live in,” Blossey said. “Hunters don’t remove enough deer, cars don’t remove enough. Their populations exploded, because the living conditions were just absolutely wonderful.”

And the wishful thinking – that wolves and other predators can control deer populations and restore degraded ecosystems – lacks evidence as well. When large predators are present in a landscape, deer and other herbivores simply graze when wolves are resting.

“Meaningfully reducing deer populations in Wisconsin alone would require tens of thousands of wolves, at least temporarily until deer populations decline – an ecologically and socially impossible scenario,” the authors write.

And wolves alone can’t undo the ecological damage humans have done, Blossey said. A popular video “How wolves change rivers,” which has been viewed more than 43 million times, suggests that the re-introduction of wolves in Yellowstone National Park triggered a cascade of effects that benefited the entire ecosystem.

“I was as fooled like everybody else by the lovely stories that came out of Yellowstone saying, you bring wolves back, and you restore the rivers, and everything’s hunky-dory,” Blossey said.

In fact, these claims may be based on the collection of selective evidence, other research has shown. “Once I started digging like an archaeologist into the literature, I found things that were not supportive of what I thought I knew,” Blossey said. Other factors, such as hunters, grizzly bears, mountain lions, bison, beaver, rainfall patterns, climate, and the quality and quantity of vegetation may have also played significant roles.

Rather than relying on myths and wishful thinking, we should see large predators like wolves as a valuable part ecological communities in their own right, Blossey said, and not just for their function.

“As long as people learn to live with and tolerate the new (old) neighbors,” the authors write, “a careful but not fully conflict-free existence appears possible.”

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JOURNAL

Frontiers in Conservation Science

DOI

10.3389/fcosc.2022.881483 

Panthers now No. 1 predator of white-tailed deer in Southwest Florida

 

A new study by the University of Georgia found Florida panthers are the No. 1 cause of mortality for white-tailed deer in Southwest Florida.

The researchers set out to get a better picture of what factors most affect the survival of Florida’s white-tailed deer, the most popular game species in the state and a key prey species for the Florida panther.

Published this month in the Journal of Applied Ecology, the publication is part of the South Florida Deer Study, a large-scale white-tailed deer research project funded by the Florida Fish and Wildlife Conservation Commission from 2015 to 2019.

The number of deer killed by Florida panthers was very high compared to previous studies, said Richard Chandler, associate professor in the UGA Warnell School of Forestry and Natural Resources. Of the 241 deer captured and fitted with GPS collars during the study, 96 were killed by Florida panthers. During the 1990s, few deer were killed by panthers and the main sources of mortality came from bobcats and hunter harvest. In the new study, only seven deer were killed by bobcats, and only one deer was harvested by hunters.

“Panther predation went from a very small source of mortality to now being the dominant source of mortality for deer,” Chandler said.

Listed as endangered by the U.S. Fish and Wildlife Service, the Florida panther represents the only population of pumas in the eastern United States. Genetic restoration efforts began in the mid-1990s in response to low population and inbreeding concerns, and the panther population has increased substantially over the last 20 years, from 20 to 30 in the 1990s up to 200 in 2017. 

Population, habitat changes pose challenges for deer

The increase in panther predation on deer comes amid a larger shift taking place across the landscape. The Comprehensive Everglades Restoration Plan now underway will restore natural waterflows and benefit many aspects of the ecosystem, but it may also flood land that was already marginally hospitable to deer. The study found that deep water had a negative effect on female deer survival, although no cases of drowning were recorded.

Amid the landscape changes, Florida wildlife officials strive to maintain sustainable deer hunting opportunities. As in other parts of the country, there is a long, culturally important tradition of deer hunting in South Florida, and hunters provide a large amount of the funding for wildlife conservation in the state. Agencies must balance hunting opportunities with other public interests and panther conservation efforts.

“They have restricted hunter harvest quite a bit for the benefit of the deer population and to make sure there’s plenty of prey for panthers. But it’s a balancing act,” said Chandler. “They don’t want to shut down hunting opportunities, but they don’t want harvest to be so high that it suppresses the prey population and keeps the panthers from recovering. … That’s a big challenge, and it’s not easy. Our results emphasize how difficult that will be. Future work is needed to determine if additional habitat management can bolster the deer population for the benefit of panthers and people.”

The study required teams of experts and technicians working year-round in remote areas of Southwest Florida.

The project’s co-investigators featured renowned deer experts and retired Warnell professors Karl V. Miller and Robert Warren, along with Mike Connor with the Jones Center at Ichauway, Warnell alumnus Mike Cherry, who now leads the deer research program at the Caesar Kleberg Wildlife Research Institute at Texas A&M University, David Shindle with the U.S. Fish and Wildlife Service, and Elina Garrison with the Florida Fish and Wildlife Conservation Commission.

The study’s lead author, UGA postdoctoral researcher Florent Bled, is now a scientist with the Florida Fish and Wildlife Conservation Commission. Graduate students Daniel Crawford, Brian Kelly, Heather Abernathy, Hunter Ellsworth, Lydia Stiffler and Kristin Engebretsen provided key support to the project, which benefited from assistance from the Big Cypress National Preserve, National Parks Service, and the USFWS Florida Panther National Wildlife Refuge.

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JOURNAL

Journal of Applied Ecology

DOI

10.1111/1365-2664.14201 

The answer to keeping moose populations healthy? Wolves

 Predators may keep prey populations healthy by acting as a selective force against genetic diseases. A new study found that wolves select adult moose based on age and osteoarthritis, a chronic disease that can be influenced by genetics. Wolves also showed a strong preference for elderly moose over prime-aged adults. The results indicate that wolves play an important role in keeping prey populations healthy and have considerable implications for the conservation management of predator and prey populations.

Over the last decade, wolves have been at the center stage of conservation news. They were once one of the most widely distributed wild mammals on Earth. But after decades of habitat destruction and human persecution, wolves now only occupy about two thirds of their former range.

Wolves as biodiversity managers

Now, the wolf is making a comeback. The US has seen an increase in their wolf populations across the country, and extensive conservation efforts have led to a comeback across Europe. Yet their return has not been well-received by everyone. Predators may lead to human-wildlife conflicts, as wolves can pose a threat to livestock and pets.

Even so, multiple case studies, such as the reintroduction of wolves in Yellowstone, have shown that the presence of wolves favors ecosystem health. Wolves keep prey populations, such as deer, elk, and moose, in check, which benefits vegetation. Carcasses left behind by wolves provide food for other animals such as scavengers and redistribute nutrients.

A new study published in Frontiers in Ecology and Evolution found another way in which wolves may be beneficial for biodiversity: selective predation. Wolves preyed more on prime-aged adult moose with osteoarthritis than healthy prime-aged individuals. Wolves also showed a strong preference for elderly moose over prime-aged adults.

Selective predation

Selective predation means that a particular type of prey occurs more frequently in a predator's diet than what is expected based on the prey type's frequency in an environment. Predators tend to select individuals that are easier or less risky to hunt.

Selective predation can have important impacts on prey population dynamics. Prey population growth rates are less impacted by predation when predators go for juveniles or elderly adults, as these individuals have lower reproductive values.

Less well understood is the impact of predation of sick individuals on prey population health.

“Wolf biologists have in the past assumed that wolves play an important role in regulating the health of prey populations by selectively removing old or diseased animals,” said Dr Sarah Hoy, of Michigan Technological University. “However, a rigorous assessment of that idea has not been tested until now.”

Healthy moose populations

Hoy and her colleague assessed the extent that wolves select adult moose on the basis of age-class and osteoarthritis.

“Osteoarthritis is a progressively crippling disease caused by deterioration of cartilage on the surfaces of moveable joints (for example, knees and hip joints),” explained Hoy. “As individuals get older, they are more likely to develop osteoarthritis and develop more severe forms of the disease.”

They also examined how temporal variation in kill rates were associated with the subsequent incidence of osteoarthritis in the moose population over a 33-year period.

“When it comes to wolves and moose, it makes a lot of sense that wolves would preferentially target moose that are in poorer condition because adult moose weigh between 800 and 900lbs which is between eight and 10 times as heavy as a wolf,” said Hoy.

They found that wolves showed strong selection for elderly moose and avoided prime-aged adults. The presence of severe osteoarthritis, but not mild or moderate, increased the vulnerability of prime-aged moose to predation.

“But the situation is different for older moose. While older moose are more vulnerable to predation, that vulnerability does not strongly depend on whether an old moose has osteoarthritis,” explained Hoy.

They also found that the incidence of osteoarthritis in the moose population declined following years with higher kill rates.

“The decline in osteoarthritis following years with more predation is – we think – because wolves preferentially removed moose with osteoarthritis from the population,” said Hoy. 

Wolf conservation

The results have important implications for wolf management and conservation. Hoy explained: “The management and conservation of wolves is controversial among the public. Yet our results suggest wolves might be an effective, natural, and more ethical way of regulating the health of deer and moose populations – as opposed to using culls or recreational hunting to reduce the incidence of diseases or parasites of concern.”

“The results are also relevant for policy-related arguments about reasons to refrain from intensively hunting wolf populations,” continued Hoy.

“When deciding whether to hunt wolves it is important to not only consider issues that may be caused by wolves (ie, occasional predation of livestock) but to also consider the important ecological benefits that wolves may provide by removing old and diseased animals from the populations.”

JOURNAL

Frontiers in Ecology and Evolution

DOI

10.3389/fevo.2022.819137 

Caribou herd rebounds as Indigenous stewards lead conservation efforts

 

IMAGE: IN PARTNERSHIP WITH MANY ORGANIZATIONS AND GOVERNMENTS, A NEW INDIGENOUS-LED CONSERVATION INITIATIVE HAS HELPED IMPROVE A KLINSE-ZA CARIBOU POPULATION. view more 

CREDIT: UBC OKANAGAN

Despite recovery efforts from federal and provincial governments, caribou populations across Canada continue to decline, largely due to human activity.

But as a new UBC Okanagan study finds, in central British Columbia there is one herd of mountain caribou, the Klinse-Za, whose numbers are going in the opposite direction—all thanks to a collaborative recovery effort led by West Moberly First Nations and Saulteau First Nations.

In partnership with many organizations and governments, the Indigenous-led conservation initiative paired short-term recovery actions such as predator reduction and caribou guardians at maternal pens, with ongoing work to secure landscape-level protection in an effort to create a self-sustaining caribou population.

Their efforts paid off.

Dr. Clayton Lamb, a Liber Ero Fellow, along with Carmen Richter, a biology master’s student, and Dr. Adam T. Ford, Canada Research Chair in Wildlife Restoration Ecology, conduct research in the Irving K. Barber Faculty of Science. Their latest study shows Klinse-Za caribou numbers have nearly tripled in under a decade.

“We have an Indigenous-led conservation effort to thank for averting the looming extinction of this herd,” says Dr. Lamb. “The population was declining rapidly—a West Moberly Elder once described the herd as a ‘sea of caribou,’ but by 2013 it had declined to only 38 animals.”

Today, the herd count is more than 110 and numbers continue to rise.

“This work provides an innovative, community-led, paradigm shift to conservation in Canada,” Dr. Lamb says. “While Indigenous Peoples have been actively stewarding landscapes for a long time, this approach is new in the level of collaboration among western scientists and Indigenous Peoples to create positive outcomes on the land and put an endangered species on the path to recovery.”

Richter, who is a Saulteau First Nations member, says Indigenous communities have really come together for the good of the caribou.

“We are working hard to recover these caribou. Each year, community members pick bags and bags of lichen to feed the mother caribou in the pen while other members live up at the top of the mountain with the animals. One day, we hope to return the herds to a sustainable size,” she says.

Though the partnership has yielded great success, Dr. Ford is the first to acknowledge that more time and effort will be needed to fully recover the Klinse-Za.

“This work is also an important part of decolonizing the mindset of conservation, which has historically worked to exclude the views of Indigenous Peoples,” he adds.

With caribou declines exceeding 40 per cent in recent decades across Canada, many populations have already been lost. But Dr. Ford insists there is a brighter path forward, and this study proves it.

“This is truly an unprecedented success and signals the critical role that Indigenous Peoples can play in conservation,” he says. “I hope this success opens doors to collaborative stewardship among other communities and agencies. We can accomplish so much more when working together.”

This study was co-produced by western scientists and members of West Moberly First Nations and Saulteau First Nations. The work was recently published in Ecological Applications and is supported by a companion manuscript in Ecological Applications exploring the expeditious population growth.

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JOURNAL

Ecological Applications

DOI

10.1002/eap.2581 

Tree cover helps gray foxes coexist with coyotes in the country

As coyotes have spread outside their native range into the eastern United States, they’ve been known to harass and kill North Carolina’s two native species of fox. A new study finds that preserving tree cover may be essential in helping the gray fox survive with coyotes in rural areas, probably because of the fox’s unusual ability to climb trees.

In the study, researchers used camera traps to find out where gray foxes coexist with coyotes in suburban, rural or wild areas of North Carolina. Surprisingly, they found gray foxes can coexist with coyotes in suburban forest fragments. However, in rural zones, they avoid areas where coyotes live that lack adequate tree cover.

“Coyotes are well known to persecute smaller foxes,” said study co-author Roland Kays, research associate professor at North Carolina State University and director of the NC Museum of Natural Sciences Biodiversity & Earth Observation Lab. “They go out of their way, more than you see in other interactions between species, to really bully, chase and kill the smaller foxes. There is some reason for concern if this species is going to survive. How is that going to happen in an urban environment where you also have people?”

Coyotes have spread across North America from their native range in parts of the western United States, taking advantage of the fact that larger predators – such as cougars and wolves – aren’t found in most of the eastern U.S. anymore.

“The general trend has been a decline in all carnivores, but there are some exceptions, and the coyote is one of the big exceptions,” Kays said.

Researchers wanted to know how coyotes might impact where native species like the gray fox are now found – especially since urbanization could affect how the two species interact by fragmenting their habitats and disrupting food sources.

“Foxes are fairly common in urban areas, perhaps in part because coyote numbers are relatively low,” said the study’s lead author Arielle Parsons, postdoctoral research associate at NC State. “In the Midwest and western United States, there are indications of ‘apparent decline’ in fox populations concurrent with coyote population increases. We don’t know if it’s a true decline yet, but there’s evidence it is.”

The researchers used wildlife photos taken by volunteers to figure out where foxes and coyotes coexist. The photos came from 915 motion-sensitive cameras that volunteers placed in yards, forest fragments and open areas in suburbs, dense suburbs, rural and wild areas. Researchers used the photos to develop a model of whether the two species are likely to be found together, and at what times.

From 347 pictures of coyotes and 943 pictures of gray foxes, they found that the two species are most likely to be found together in areas of high housing density and low forest cover – i.e, the suburbs. Coyotes were generally less likely to live in high density housing areas than the gray fox.

“These two species were more likely to use the same sites in suburban areas, especially small forested wood lots,” Parsons said. “We expected them to use these wood lots at different times to avoid each other, but actually we found that they use these suburban forest fragments at the same time.”

The researchers hypothesized that they could coexist in the suburbs because coyotes are just moving through, not establishing territories, and there are still relatively few of them.

“If they’re just moving through, they may not be as prone to direct competition, or bullying of the gray foxes, or their movements are hard for the gray foxes to predict,” Parsons said. “We also think gray foxes might not have a good way to avoid coyotes consistently in suburbs, since habitat is scarce, or avoidance isn’t necessary given abundant suburban resources.”

In rural areas, the two species were less likely to be seen together. However, gray foxes were more likely to inhabit a site as tree cover increased.

“Gray foxes are very good at climbing trees; they have sharp claws,” Kays said. “They’re one of the only dog relatives that can climb trees. Coyotes can’t. It could be that climbing trees helps them deal with coyotes.”

Researchers also saw a slight shift in the gray foxes’ timing, with the gray foxes more likely to be nocturnal around coyotes. 

Overall, researchers said findings for rural areas suggest gray foxes could be at risk in areas with few houses and little tree cover.

“In rural areas, where we’re seeing gray foxes spatially and temporally avoid the coyotes, that’s where we could see some impact on the gray fox population,” Parsons said. “It could mean the coyote is outcompeting, bullying or even killing gray foxes there. A strong competitive relationship may result in gray foxes not being able to access high quality areas, forcing them to establish themselves elsewhere where resources may not be as abundant. That could be a mechanism behind a decline.”

They found an important benchmark of tree cover is important for gray foxes in rural areas: Tree cover in more than 50% of a 1-kilometer radius resulted in gray foxes being more likely to occupy a site.

“Enhancing and preserving tree cover as much as we can is going to be beneficial for gray foxes,” Parsons said.

Researchers said another takeaway is that humans can impact how species are able to adapt and coexist.

“There are things we can do to change the ways wildlife species are able to adapt to human-dominated environments,” Parsons said. “Reducing habitat fragmentation and preserving forest and green spaces can help enhance the ability for these species to coexist.”

The relationship is evolving over time, they added, and could change. Researchers are continuing to study the populations of the two species over the long term.

The study, “The effect of urbanization on spatiotemporal interactions between gray foxes and coyotes,” was published online in Ecosphere on March 20, 2022. It was authored by Kays, Parsons, Kenneth Keller, Christopher Rota, Stephanie Schuttler and Joshua Millspaugh. The study was funded by the National Science Foundation through grants 1232442 and 1319293 and the North Carolina Museum of Natural Sciences.

-oleniacz-

Note to editors: The abstract follows.

“The effect of urbanization on spatiotemporal interactions between gray foxes and coyotes.”

Authors: Arielle Parsons, Kenneth Keller, Christopher Rota, Stephanie Schuttler, Joshua Millspaugh and Roland Kays.

Published online in Ecosphere on March 20, 2022.

DOI: 10.1002/ecs2.3993

Public conservation voting on restoring gray wolves to Colorado

Author contact: Mark Ditmer (mark.ditmer@gmail.com)

Over 3 million voters in Colorado recently weighed in on Proposition 114, a ballot measure to restore the gray wolf to its former range within the state. Previous public opinion polls suggested widespread support for wolf restoration, but the proposition passed with only a slim margin (50.9% of the total vote), and according to new research from Colorado State University scientists, there was a strong relationship between support for the ballot initiative and political support for the Democratic candidate for president in the 2020 election. Additionally, areas closer to proposed wolf restoration areas showed less support for the ballot initiative. Without considering presidential votes, there was a positive relationship between educational attainment and support for wolf restoration. However, when accounting for presidential votes, the team found that voters for President Biden in precincts with lower levels of education had relatively higher levels of support for wolf restoration than voters in precincts with higher educational attainment.

Previous studies have explored the relationships between demographics, livelihood, and self-reported attitudes and beliefs, but few have examined how these factors correspond to actual public behavior, i.e. voting.  

Read the article: Socio-ecological drivers of public conservation voting: restoring gray wolves to Colorado, USA.

Human disturbance is the most crucial factor for lynx in habitat selection

 Habitat selection in wildlife is a process that occurs at different scales: Balancing advantages, such as high abundance of food, with disadvantages, such as human disturbance. Large predators, with their large spatial requirements, are particularly sensitive to these disturbances. A team led by conservation biologists Prof. Dr. Marco Heurich and Joseph Premier from the Faculty of Environment and Natural Resources at the University of Freiburg has studied this habitat selection process in Eurasian lynx. Their results, published by the researchers in Biological Conservation, provide important information for the conservation of this species in human-dominated landscapes. "Through this study, we can generalize the habitat selection behavior of a large carnivore species on a continental scale fort he first time," explains Heurich.

Large dataset with animals in several European areas

The researchers led by Heurich and Premier used a data set consisting of tracking data on 125 lynx from nine study areas across Europe. They compared the locations available to and actually used by the predators at two scales: the landscape scale, which shows how lynx place their home range in the landscape, and the home range scale, which shows how lynx select the habitats within their home range. For this comparison, the research team used a novel machine learning approach called the random forest. This was extended to include a random effect so that variability within and between study areas could be accounted for.

What the animals avoid and how they orient themselves

On the landscape scale the analysis revealed that lynx avoid roads and human settlements. On the level of their home range, the animals were oriented towards hiding places and the availability of prey. The researchers found only minor differences between female and male lynx in their choice of habitat.

Heurich and Premier found the greatest differences in lynx habitat choice at the landscape level, where there were clear differences between the various study areas, for example between the Swiss Alps and the plains of Estonia. Within the foraging areas, lynx behaved very similarly throughout Europe, preferring heterogeneous forest areas and areas that provided protection from human disturbance.