What do lynx, flying squirrels, ravens, and wolverines have in common?

They will all scavenge from snowshoe hare carcasses under the right conditions, according to a new study by University of Alberta ecologists. And they're not alone. In fact, researchers documented 24 different species feeding from snowshoe hare carcasses in Canada's northern boreal forest.

"This is one of the most diverse scavenger communities recorded," said lead author Michael Peers, who conducted this research during his PhD studies under the supervision of ProfessorStan Boutin in the Department of Biological Sciences.

"Species we may think of as scavengers like common ravens, magpies, and wolverines were recorded, but also species that people might not expect to be scavengers. We documented snowshoe hares, Canada lynx, red squirrels, Northern flying squirrels, arctic ground squirrels, and chipmunks all scavenging."

The researchers examined the northern boreal forest in the Yukon over a four-year period from 2015 to 2018. Using remote sensing cameras, the researchers examined which animals scavenged from nearly 100 opportunistically placed snowshoe hare carcasses throughout the region.

The results indicate that prey species may have a more complex impact on food webs than previously thought, because their numbers influence both their direct predators as well as other animals who commonly scavenge.

"Scavenging by animals can have important impacts on food webs, but is often overlooked in food web research," explained Peers. "Our data shows that a lot of species scavenge in the boreal forest of Canada, and that changing temperatures or the abundance of keystone species can impact scavenging communities."

Industry-made pits are beneficial for beavers and wolverines

In Northern Alberta, pits created by industry activity may support beavers and subsequently wolverines

UNIVERSITY OF ALBERTA

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IMAGE: BEAVERS, LIKE THE ONE PICTURED HERE, ARE MAKING THEIR HOMES ON SITES OF INDUSTRY ACTIVITY. IMAGE CREDIT: A. COLTON. view more 

CREDIT: A. COLTON.

Beavers and wolverines in Northern Alberta are using industry-created borrow pits as homes and feeding grounds, according to a new study by University of Alberta ecologists.

The research examined the relationship between local wildlife and borrow pits, which are industry-created sites where material such as soil, gravel, or sand has been dug up for road construction. The results show that when revegetated the sites provide homes for beavers, which in turn support the survival of wolverines.

"The borrow pits enhance habitats for a number of species of wildlife in the bogs of Northern Alberta," said Mark Boyce, co-author on the paper, professor in the Department of Biological Sciences, and Alberta Conservation Association Chair in Fisheries and Wildlife.

"The deep water and adjacent forage create excellent habitats for beavers. And wolverines thrive when beavers do. Not only do they prey on beavers, wolverines also have been shown to use beaver lodges as dens where they have their cubs."

The displacement of wildlife by industrial development is a complex issue, Boyce explains. "In this case, industrial development created the borrow pits that are now used by beavers that actually enhances habitats for our wilderness icon, the wolverine."

The research was led by PhD student Matthew Scrafford, who formed a partnership with the Dene Tha First Nation that proved instrumental for the study.

"The most important partner on this research was the Dene Tha First Nations," said Boyce. "Several young people in the area were enthusiastic about the project. They were instrumental in building traps and supporting our research."

No evidence that predator control will save mountain caribou

Addressing potential threats from predators has not slowed the dramatic decline of mountain caribou in British Columbia and Alberta, according to a new study by scientists from the University of Alberta and two other western Canadian universities.

Biologists reassessed data from research published in the Proceedings of the National Academy of Sciences (PNAS) in 2019. The original research has been cited as showing that killing wolves and fencing pregnant caribou are solutions to saving the endangered animals.

The scientists looked closely at the data provided in the 2019 study, and found that when routine statistical tests were included, predator control lacked statistical support. They found that some of the steepest declines in caribou populations were in southern British Columbia, areas where wolves are not major caribou predators.

"No matter how you calculate it, the statistics don't back up culling wolves or fencing in caribou," said Viktoria Wagner, assistant professor in University of Alberta's Department of Biological Sciences and co-author.

Instead, the authors found that statistically caribou declines tracked closely with specific mountain caribou ecotypes. The deep-snow mountain caribou found from Wells Gray Park into the Kootenays experienced the steepest declines despite having a low number of caribou killed by wolves.

"This means something is going on that's killing off an endangered species and it isn't being addressed by predator management," said Toby Spribille, assistant professor in the Department of Biological Sciences and co-author on the study. He noted that although focusing on predator threats is simple and easy to communicate, it does not capture the interactions that are causing mountain caribou to go extinct. For instance, the loss of habitat to logging, snowpack variation and snowmobiling are factors that need to be addressed, the authors say.

"This is an uncomfortable conversation to have but it should not be left out of scientific models," noted Spribille."If decision-makers are going to be serious about species conservation, it's really critical that they get all the information."

"Forests provide caribou with refuge from wolves and separation from other prey animals, including elk, moose, and deer," said Lee Harding, retired Canadian Wildlife Service biologist and lead author on the study. "Without them, caribou must constantly be on the move to find food, exposing them on all sides. Predators are just one of the hazards."

Chris Darimont, professor at University of Victoria, Mathieu Bourbonnais, assistant professor at University of British Columbia Okanagan, and Andrew Cook, PhD student in UAlberta's Department of Biological Sciences, collaborated on this research.

Are protected areas effective at maintaining large carnivore populations?

UNIVERSITY OF HELSINKI

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IMAGE: BROWN BEAR IN EASTERN FINLAND. INTERESTINGLY, THE EFFECTS OF PROTECTED AREAS ON BEAR DENSITIES VARIED DEPENDING ON THE METHODOLOGY USED. view more 

CREDIT: DANIEL BURGAS-RIERA

A recent study, led by the University of Helsinki, used a novel combination of statistical methods and an exceptional data set collected by hunters to assess the role of protected areas for carnivore conservation in Finland.

Overall, protected areas do not harbour higher densities of large carnivore species than unprotected lands. These areas even had declining wolverine densities within their limits while populations outside remained overall stable over a 30-year study period. The study was published in the journal Nature Communications.

The international group of authors, led by Dr Julien Terraube from the Faculty of Biological and Environmental Sciences at the University of Helsinki, proposes that the results do not indicate that protected areas are unimportant for carnivore conservation, as they may support seasonal habitats and prey for these highly mobile species. However, the outcomes highlight complex socio-ecological pressures on carnivore populations that vary in both time and space and affect the conservation outcomes of protected areas. For example, the largest Finnish protected areas are located in Lapland, and due to their sizes these areas are most suitable for large carnivores. However, the areas seem unable to maintain stable wolverine populations, which may be linked to increased conflicts with herders in the reindeer husbandry area.

"Wolverines are only found in three Nordic countries within the European Union, and therefore Finland plays an important role for the conservation of this species", explains Dr Terraube. He adds: "The negative trend of wolverine populations inside northern protected areas is alarming and highlights that further research is needed to understand the dynamics of wolverine populations in Lapland, how this species is affected by illegal killing and what protected areas could do to improve this situation".

On a brighter note, the researchers also found lynx densities to be higher within protected areas located in eastern Finland than those located in the western part of the country. The ecological factors that may influence this, such as prey abundance or connectivity to healthy Russian populations, remain unexplored.

The po­ten­tial of cit­izen science for as­sess­ing the im­pact of pro­tec­ted areas

The results show that counterfactual approaches applied to long-term and large-scale data are powerful analytical tools for evaluating the effectiveness of protected areas in maintaining wildlife populations. A counterfactual approach means comparing protected and unprotected sites that have similar environmental characteristics or human-caused threats. The method has been increasingly used to assess the effectiveness of protected areas in halting deforestation. This allows researchers to isolate the effect of protection on land cover from other confounding factors such as elevation. Until now, these types of approaches focused on matching analyses have been restricted to studies investigating the effects of protected areas on land-use changes. Finding wildlife time series with enough temporal and spatial coverage to conduct such robust effectiveness assessments is often difficult.

Dr. Terraube explains: "We were able to use data collected through the Finnish Wildlife Scheme to conduct this study. Hunters throughout the country have collected this data set since 1989, offering a fantastic opportunity to apply matching analyses to wildlife data for the first time and to assess large-scale and long-term patterns of protected area effectiveness. We chose to focus on large carnivores, as this species group is particularly prone to rising conflicts with local communities. Carnivore-human conflicts have increased in Finland following the recent recovery of most carnivore species. This has resulted in increasingly negative attitudes towards certain species, such as the wolf, and to increased levels of illegal killing".

Main­stream­ing im­pact eval­u­ation: to­wards bet­ter man­age­ment of pro­tec­ted areas

The study highlights the need to design robust methodological tools to strengthen our understanding of conservation outcomes and opens new avenues for improving protected area impact assessments. This is of the utmost importance, as the international community is currently turning to the post-2020 targets drafted by the UN Convention on Biological Diversity aiming to upgrade protected areas in an attempt to halt global biodiversity loss.

"We argue that this study shows that, despite methodological challenges, robust assessments of protected area effectiveness for the conservation of wide-ranging species, such as large carnivores, are possible and greatly needed as a basis for further research. It also highlights the extraordinary value of long-term wildlife monitoring activities conducted by citizens across an entire country", concludes Dr Terraube.

Positive YouTube videos of wolves linked to greater tolerance

NORTH CAROLINA STATE UNIVERSITY

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A new study from North Carolina State University suggests that people have more tolerance for wolves after seeing positive videos about them, which could make YouTube an important wolf conservation tool.

"One of the cool things about these results is that positive messaging was effective for changing people's views. People had more positive attitudes, greater willingness to accept wolves, and were more likely to take action to help their conservation - no matter their political identity or their age - after watching positive videos," said Nils Peterson, senior author of the study and a professor in NC State's Department of Forestry and Environmental Resources.

"A lot of wildlife species we care about only need tolerance to persist in a landscape," Peterson added. "They're not domestic animals that need a lot of help from us. They just need us not to kill them or destroy their habitat."

In the study, researchers evaluated how a group of 273 people rated their tolerance for wolves before and after watching either a playlist of five different negative videos, a playlist of five different positive videos, or a neutral video.

To measure their tolerance, researchers asked questions in three categories: they asked participants about their overall attitudes toward wolves, such as whether they thought wolves were "good" or "bad;" their level of acceptance of wolves in their state and near populated areas; and their intended behaviors, or whether they would be likely to act for or against wolves or their conservation.

Survey participants had positive attitudes, acceptance and behavior intentions about wolves prior to receiving any treatment, but researchers saw that positive videos could still increase attitudes, acceptance and participants' willingness to act. They also saw those changes regardless of whether the viewer identified as conservative or liberal.

"Everybody is on social media these days, including state wildlife agencies, federal agencies, nonprofits, and everybody is putting content out there," said the study's lead author Will Casola, a Ph.D. student at NC State. "This study shows that this material actually has the potential to influence people, and they're not just putting time and resources into something that goes in one ear and out the other."

However, people who identified as liberal were more likely than conservatives to show positive changes in favor of wolves in measures of attitudes, acceptance and intended behaviors regardless of the videos they watched.

"We didn't see anything that would suggest people reacted differently to each video treatment depending on their political affiliation," Casola said. "Instead, we saw that no matter which videos they watched, liberals were more likely to exhibit positive changes."

The largest changes in tolerance were linked to older age. People above the age of 40, regardless of political background, were more likely to have larger changes in their attitudes for or against wolves.

While negative videos also led to decreased tolerance for wolves, this change was less dramatic.

"There's a lot of literature out there that shows that positively framed messages are more powerful than negatively framed messages, and these findings reinforce that," Casola said.

Researchers saw improvements in respondents' willingness to act for wolf conservation overall, but except for signing petitions to support wolf re-introduction, respondents showed reluctance to take other specific actions to aid wolf conservation.

"People in general said they weren't likely to participate in many of these behaviors, but they were also less likely to participate in behaviors that were directly opposed to wolf recovery and conservation," Casola said.

Researchers focused on wolves since they can be controversial. While researchers said wolves are essential for maintaining a diversity of species in a landscape and improving the health of populations they prey on, they can also compete with people for space and resources, and can pose a risk for livestock.

Researchers said one unanswered question in their work is about how effective the videos were at reaching people who may not already agree with the underlying message.

"People are already asking the question: How do we get media to cross ideological bubbles that people have created?" Peterson said.

Reintroduction of wolves tied to return of tall willows in Yellowstone National Park

OREGON STATE UNIVERSITY

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IMAGE: IN YELLOWSTONE'S LAMAR VALLEY, BISON CONGREGATE IN THE SUMMER AND GRAZE NOT ONLY ON GRASS BUT ALSO ON WILLOW, COTTONWOOD, AND ASPEN. THESE BISON ARE EATING WILLOWS IN THE FOREGROUND,... view more 

CREDIT: LUKE PAINTER, OREGON STATE UNIVERSITY

CORVALLIS, Ore. - The reintroduction of wolves into Yellowstone National Park is tied to the recovery of tall willows in the park, according to a new Oregon State University-led study.

Wolves were reintroduced to the park in 1995. The new study shows their predation on elk is a major reason for an increase in the height of willows in northern Yellowstone, said Luke Painter, a wildlife ecologist at Oregon State University and lead author on the study.

There's been a debate among scientists over the degree to which willows may have recovered from decades of suppression by elk following the restoration of wolves and subsequent reductions in elk numbers, Painter said.

"Our results demonstrate that the reduction of elk browsing over the last two decades in northern Yellowstone has allowed willows to grow taller in many places, despite a warming and drying climate," Painter said, adding that willows aren't recovering in some areas due to continued browsing by increased numbers of bison.

Following wolf restoration in the 1990s, elk numbers decreased, and some researchers reported willows growing taller with reductions in elk browsing, evidence of a shift toward willow recovery.

The new study compared data from three time periods: 1988-1993, when elk densities were high and most willows very short; 2001-04, when willows may have begun to recover; and 2016-18.

The researchers confirmed that willows have indeed increased in height and cover in response to a reduction in browsing by elk.

The study is published in the journal Ecosphere.

Elk numbers in northern Yellowstone have declined from a high of nearly 20,000 in 1995 - the year wolves were restored to the park - to 4,149 counted over two days in March 2019 by biologists with Montana Fish, Wildlife, and Parks; U.S. Forest Service and U.S. Geological Survey.

Painter and co-author Michael Tercek of Walking Shadow Ecology in Montana found a strong contrast between sites along streams compared to wet meadows. Willows in meadow sites did not increase in height, but willows in stream sites increased significantly, exceeding 200 centimeters, or 6 feet - a height accessible to elk - in the summers of 2001-04 and in the spring of 2016.

They also found a significant change in willow thickets at least 200 centimeters in height along streams, with thickets occupying about 80% of willow patches in some sites, but as little as 22% in others. Tall willow thickets are an important habitat feature and an indicator of willow recovery, Painter said.

Thus, passive restoration through the return of predators has begun to reverse the loss of willows, something active culling of elk in the past was unable to accomplish, he said.

"Wolves didn't do it all by themselves," Painter said. "Other predators and hunters also affected elk, but this would not have happened without the wolves.

"This does not mean a wider expanse of willow habitat has been restored as existed in the early days of the park when beavers created large wetland expanses. This may eventually happen as beavers return but could take a long time to develop."

This is the latest OSU study led by Painter that examines the effects of wolf reintroduction to Yellowstone on trees. In 2018, he published a study that showed that aspen is recovering in areas around the park, as well as inside the park boundary.

Canada lynx disappearing from Washington state

WASHINGTON STATE UNIVERSITY

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PULLMAN, Wash. - Canada lynx are losing ground in Washington state, even as federal officials are taking steps to remove the species' threatened status under the Endangered Species Act.

A massive monitoring study led by Washington State University researchers has found lynx on only about 20% of its potential habitat in the state. The study, published recently in theJournal of Wildlife Management, covered more than 4,300 square miles (7,300 km) in northeastern Washington with camera traps but detected lynx in only 29 out of 175 monitored areas.

The results paint an alarming picture not only for the persistence of lynx but many other cold-adapted species, said Dan Thornton, an assistant professor in WSU's School of the Environment.

"Lynx are good sentinel species for climate change," said Thornton, the corresponding author on the study. "They are specialized, have larger ranges and need really cold, snowy environments. So, as they go, they are like an early warning system for what's going to happen to other climate sensitive species."

Wildfire, rising temperatures and decreasing snowpack have all hurt the lynx's ability to survive in Washington, the researchers found.

In the last 24 years, large wildfires have ripped through northeastern parts of the state, destroying habitat for lynx and their favorite food: snowshoe hare. It can take as long as 20 to 40 years for that landscape to recover.

The lack of snow and cold are also a problem, as lynx with their bigger paws are specially adapted to hunt on snow and for the prey that live there. As temperature rises, warmer adapted species like bobcat and cougar could also bring competition into lynx territory.

"We learned that lynx are responding strongly to many of these factors - snow conditions, temperature and fire - that are likely to change even more as the climate warms," said Thornton.

The connection to Canadian populations is also key for the lynx survival in Washington, and that connection is complicated by differing conservation status. In Washington state, they are protected at the state and federal levels as a threatened species. In Canada, they are harvested for their pelts.

The lynx's protected status in the U.S. may also change. Lynx are currently found in Maine, Minnesota, Montana, Colorado, Idaho and Washington, but a 2016 federal draft assessment found the species would disappear from its northern range without protection by 2100. However, a new assessment in 2018 concluded that the lynx could be removed from threatened status under the federal Endangered Species Act.

Living in high, remote areas, lynx are challenging to study, and estimates of actual individuals are difficult to make, but according to an analysis by the Washington State Department of Fish and Wildlife based on data collected in the 1980s, the state used to have about 7,800 square miles of habitat capable of supporting 238 animals. In 2017, that estimate was revised down to about 2,300 square miles capable of supporting 38 to 61 lynx. This latest study adds strong evidence that their territory in Washington is further contracting.

To document the elusive animals, WSU graduate student Travis King, the lead author on the study, covered thousands of kilometers and spent two summers in the field. He also relied upon many partners and volunteers, ranging from government natural resource agency employees and conservation groups to hikers and citizen scientists. The researchers and volunteers deployed and collected 650 camera traps which generated more than 2 million images which were, in turn, sorted with the help of dozens of WSU student volunteers.

This is the first time such a comprehensive method using camera traps to track lynx has been employed. Thornton and his colleagues are now working to use the method to estimate the lynx range in Glacier National Park in Montana.