Wolves stay put when it's snowing

Wolves travel shorter distances and move slower during snowfall events, according to new research by University of Alberta biologists. The effects were most pronounced at night, when wolves hunt, and behaviour returned to normal within a day. Wolf tracks across snow in northeastern Alberta.
Wolf tracks across snow in northeastern Alberta. The study found that wolves travel shorter distances and move slower during snowfall. Photo credit: Amanda Droghini
"Our findings suggest that there is something about actively falling snow that causes wolves to slow down," said Amanda Droghini, a former MSc student in the Department of Biological Science and lead author on the study. "We don't know the exact mechanism behind that. It's unlikely that they were staying still because they were feasting on a recent kill. Instead, active precipitation might affect wolves' hunting abilities. Like rain, snow clears the air column of scent molecules. So, maybe falling snow makes it harder for wolves to detect the smell of prey."
Over the course of two winters, the researchers used remote cameras to identify snowfall events and estimate snow depth. To study wolf movement, they collected telemetry data from 17 wolves to calculate travel speed and duration, as well as resting periods. It is the first study to examine how large carnivores respond to snowfall events.
With the effects of climate change on precipitation in the boreal forest region uncertain, it is difficult to predict the implications for wolf populations. Studies such as these increase our understanding of how large mammals react to normal snowfall events, but the type and amount of winter precipitation will likely have an impact on animal behavior and the energetic cost of movement. .
"Winter is already challenging for many wildlife species because moving through snow requires more energy. Snow can also make it harder for animals to access food resources," said Droghini, who conducted the research under the supervision of Professor Stan Boutin, Alberta Biodiversity Conservation Chair.
"Anything that increases those costs, such as increased rain-on-snow events, could lead to nutritional deficiencies, poor body condition, and even starvation as animals are unable to make up for those additional costs. That is one of the worst-case scenarios but, in truth, we know very little about potential changes to precipitation patterns and how wildlife will respond to those changes."

A future for red wolves may be found on Galveston Island

Michigan Technological University

IMAGE: This is a photographic comparison of coyotes, Galveston Island (GI) canids, and red wolves. view more 

Credit: Kristin Brzeski

The American red wolf is one of United States' greatest wildlife conservation stories. Red wolves were on the brink of extinction along the American Gulf Coast during the late 1970s when the U.S. Fish and Wildlife Service (USFWS) made a bold decision to purposely remove all remaining red wolves from the wild.
But over the past few years the wild population is once again dwindling (from about 130 individuals in the wild to a mere 30) amongst political controversy and pressure from a number of landowners to be able to shoot the wolves on their land.
In addition to the wild population, there are approximately 200 red wolves in captivity.
The entire red wolf population descends from 14 individual animals, of which only 12 are genetically represented.
"Our discovery that red wolf genes have persisted in Texas -- after being declared extinct in the wild -- was very surprising," said Brzeski, assistant professor in the School of Forest Resources and Environmental Science. "It introduces both positive opportunities for additional conservation action and difficult policy challenges."
Brzeski and her coauthors published their findings, "Rediscovery of Red Wolf Ghost Alleles in a Canid Population Along the American Gulf Coast" Dec. 10, 2018 in the journal Genes (DOI: 10.3390/genes9120618).
The researchers obtained tissue samples from two roadkill canids on Galveston Island and conducted analyses with genome-wide single nucleotide polymorphism and mitochondrial DNA from 60 animals that represented all potential sources of ancestry for the Galveston Island canids: coyotes, red wolves and gray wolves. Brzeski and others found that the Galveston Island canids have both red wolf and coyote alleles, likely related to species interbreeding during the 1970s as coyote populations expanded across North America.
This is significant because it means that red wolf genetics persist in the American southwest nearly 40 years after the species was thought to have become entirely extinct in the wild. The population on canids on Galveston Island could represent a reservoir of red wolf genes that could be used to bolster the North Carolina.
"This research shows hybrids can have conservation value through harboring extinct genes from endangered parent species," Brzeski said.

Federal judge says endangered red wolves can not be shot

The critically endangered American red wolf might have been saved from extinction.

In a scathing court decision Monday, a federal judge in North Carolina ripped the Interior Department’s management of the last red wolf population in the wild, saying that an agency sworn to uphold a congressional mandate to preserve the animals violated it over and over, and even gave private landowners the right to shoot them.

Chief Judge Terrence W. Boyle reminded the U.S. Fish and Wildlife Service, which gave the authorization, of its own statement in 1999. “Wildlife are not the property of landowners but belong to the public and are managed by state and federal governments for the public good,” he wrote.

Boyle ruled that a temporary injunction issued against Fish and Wildlife’s shoot-to-kill authorization in 2016 during the Obama administration is permanent. The agency must prove that a wolf is a threat to humans or livestock before it can make a decision to take its life.

Complete article: https://www.washingtonpost.com/science/2018/11/05/federal-judge-blasts-fish-wildlife-service-says-endangered-wolves-cannot-be-shot/?utm_term=.3e929213a3bd

 

Grizzly bears living in and around Yellowstone National Park,

A U.S. District Court judge  has restored federal protections to about 700 grizzly bears living in and around Yellowstone National Park, canceling planned hunts in Wyoming and Idaho and overturning a Trump administration finding that the iconic population had recovered. The ruling was based on his determination that the U.S. Fish and Wildlife Service had illegally failed to consider how removing the Yellowstone bears from the endangered species list would affect other protected grizzly populations, and that its analysis of future threats to the bears was “arbitrary and capricious.”

Full story: https://www.washingtonpost.com/science/2018/09/25/court-restores-federal-protections-yellowstone-area-grizzly-bears/?noredirect=on&utm_term=.63fb2ca8b377

Martens recolonized Isle Royale in the '90s,

FULL STORY

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Phil Manlick releases a collared marten on the west end of Isle Royale in March 2018.

Credit: Jonathan Pauli

After decades of trapping, the last known American marten was spotted on Isle Royale in 1917. Fifty years later, in 1966, the National Park Service planned to reintroduce martens to the national park situated in Lake Superior, but nobody knows if the agency ever followed through. Then, in 1993, martens were confirmed on the island for the first time in 76 years.

Whether these small, forest-dwelling carnivores -- valued historically for their fur -- had been hiding there the whole time, found their way back, or were introduced in the 1960s without any records has remained a mystery for the last quarter century.
But in new research published today (Aug. 23, 2018) in the journal Scientific Reports, University of Wisconsin-Madison researchers in the Department of Forest and Wildlife Ecology, collaborating with the National Park Service, traced the recolonization to martens likely arriving in the 1990s, shortly before they were spotted.
Genetic studies of martens from Isle Royale and nearby populations in America and Canada showed that the contemporary population came from nearby Ontario, Canada. The animals likely wandered over on an ice bridge in the winter, the researchers speculate.
The results provide much-needed context about the natural history of an island long considered an unspoiled wilderness, but one with a long history of ecological disruptions and recoveries. The island park may be best known for the ebb and flow of its wolf and moose populations, which have been tracked for 60 years.
With additional wolves set to be relocated to Isle Royale in the coming months, the new research provides ecologists and land managers with a fuller picture of how dynamic even seemingly isolated island ecosystems can be.
After all, say the researchers, if the house-cat-sized marten can find its way over, islands like Isle Royale may be less isolated and static than we think.
Jonathan Pauli, a professor of forest and wildlife ecology at UW-Madison, has studied martens for years as part of efforts to understand how communities of wild animals respond to human disturbance. In 2015, his group provided evidence that martens had long escaped detection on islands in southeastern Alaska prior to deliberate reintroduction efforts in the 20th century. And in work published in 2016 with graduate student Phil Manlick, Pauli called into question the effectiveness of periodic augmentations of reintroduced marten populations in Wisconsin, where the once-extirpated carnivore remains an endangered species.
Part of the problem in studying martens: They're hard as heck to spot in the wild.
"I've never seen a Wisconsin marten without trapping one," says Manlick.
Manlick, Pauli and co-author Mark Romanski of the National Park Service collected marten scat samples on the island from 2006 to 2008 and again from 2012 to 2013. They gathered additional samples from nearby marten populations in Canada, Minnesota, Wisconsin and Michigan's Upper Peninsula. Samples from a different species, the Pacific marten, located in Colorado, served as a comparison. In total, the researchers collected samples from 230 individuals.
They analyzed DNA extracted from the samples to get a genetic fingerprint of the different populations. The team then evaluated three possible colonization scenarios: that an ancient population of martens had escaped detection after presumed extirpation, that the planned 1966 reintroduction actually occurred and was successful, or that a more recent reintroduction took place.
An initial analysis of the martens' DNA showed that the Isle Royale population was related to martens from Ontario. But the island population's DNA fingerprint was different, unique enough to suggest that they might have been isolated from the mainland for sufficient time to diverge into their own subpopulation. This distinct pattern supported the idea that a hidden population of martens had escaped detection during the 20th century.
"If something's been isolated out there for thousands of years, there's going to be some (genetic) mutations that build up in that population, where they're going to look distinct from everybody else around them," says Manlick, explaining how, over generations, genomes slowly accumulate mutations. "And that's what we anticipated seeing. But we didn't."
A closer look at DNA from the mitochondria -- the energy-generating part of the cell has its own, tiny genome -- revealed that the Isle Royale martens were part of one larger, common population around Lake Superior.
"They actually look just like all the other martens in the region who have come from Ontario and Minnesota and Michigan, and all these groups of martens all kind of look the same" genetically, says Manlick.
The low genetic diversity of the Isle Royale martens indicated that their population had experienced a severe genetic bottleneck. Analysis of the bottleneck estimated that the island's population began with just two individuals -- or even one pregnant female -- and that they migrated to the island less than a generation before samples were first collected in the early 2000s.
In other words, Isle Royale's martens repopulated the island just before they were spotted again, in 1993, after a 76-year absence. Though it's impossible to prove, the researchers venture that the martens walked 16 miles over an ice bridge from Ontario, a known pathway for other animals. Such connections to land are becoming less common in a warming climate.
"Much of what we understand about the island and its ecosystem evolves as we develop new techniques for analysis. At the onset of the project I was pulling for a remnant population, but to find out that martens just arrived blew my mind," says Romanski. "I am used to being wrong, but in this instance I certainly don't mind, as the story is richer."
"If they naturally colonized the island, it has implications for the management of Isle Royale in general," says Pauli.
That's because ongoing management decisions, such as the relocation of more wolves to the island slated for this fall, are based in part on assumptions that the island ecosystem won't recover from disturbances without human help. But the small marten found its way back. So might other species. The take-home lesson, say the researchers, is that even protected, isolated ecosystems can be resilient and are rarely static.
"This does suggest that these islands are maybe not as insulated as we think," says Pauli, "and that they are indeed way more dynamic than we give them credit for."

Wolf reintroduction: Yellowstone's 'landscape of fear' not so scary after all

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Utah State University scientists have shown that a 'landscape of fear' does not keep Yellowstone elk from using risky habitats where wolves kill them. In an Early View online article of Ecological Monographs, the researchers discuss how elk use nightly lulls in wolf activity to safely access dangerous areas.

Credit: Chad Wildermuth

After wolves were reintroduced to Yellowstone National Park in the mid-1990s, some scientists thought the large predator reestablished a 'landscape of fear' that caused elk, the wolf's main prey, to avoid risky places where wolves killed them. This fueled the emerging idea that predators affect prey populations and ecosystems not only by eating prey animals, but by scaring them too. But according to findings from Utah State University ecologists Michel Kohl and Dan MacNulty, Yellowstone's 'landscape of fear' is not as scary as first thought.

"Contrary to popular belief, the wolf is not a round-the-clock threat to elk; it mostly hunts at dawn and dusk, and this allows elk to safely access risky places during nightly lulls in wolf activity," says Kohl, who completed a doctoral degree at USU in 2018 and is lead author of the paper. "Despite their Hollywood portrayal as nighttime prowlers, wolves tend to hunker down at night because their vision is not optimized for nocturnal hunting."

With colleagues Daniel Stahler, Douglas Smith, and P.J. White of the U.S. National Park Service, Matthew Metz of University of Montana, James Forester of University of Minnesota, Matthew Kauffman of University of Wyoming, and Nathan Varley of University of Alberta, Kohl and MacNulty report their findings in an Early View online article of Ecological Monographs. The article will appear in a future print edition of the Ecological Society of America publication. The team's research is supported, in part, by the National Science Foundation.


The researchers revisited data from 27 GPS radio-collared elk that had been collected in the early years after the reintroduction, 2001-2004, but never fully analyzed. These collars recorded the location of each elk every 4-6 hours. This was the first time GPS technology had been used to track Yellowstone elk, and no one imagined that elk might sync their habitat use to the wolf's 24-hour schedule. Little was known about this schedule until researchers first equipped wolves with GPS collars in 2004.

"In the days before GPS, when we tracked wolves by sight and with VHF radio-telemetry, we knew they hunted mainly in the morning and evening, but we didn't know much about what they did at night" says MacNulty, a veteran Yellowstone wolf researcher and associate professor in USU's Department of Wildland Resources and the USU Ecology Center. "GPS data showed that wolves were about as inactive in the middle of the night as they were in the middle of the day."

Kohl used the GPS data to quantify the 24-hour schedule of wolves, and he compared how elk use of risky places -- sites where wolves killed elk -- differed between periods of high and low wolf activity. "Elk avoided the riskiest places when wolves were most active, but they had no problem using these same places when wolves were least active," says Kohl. "An elk's perception of a place as dangerous or safe, its landscape of fear, was highly dynamic with 'peaks' and 'valleys' that alternated across the 24-hr cycle in response to the ups and downs of wolf activity."

The ability of elk to regularly use risky places during wolf downtimes has implications for understanding the impact of wolves on elk and the ecosystem at large. "Our results can explain why many other studies found no clear-cut effect of wolf predation risk on elk stress levels, body condition, pregnancy, or herbivory," says MacNulty. "If our results reflect typical elk behavior, then actual killing rather than fear probably drives most, if not all, of the effect of wolves on elk and any cascading effect on the plants that elk eat such as aspen and willow."

This conclusion runs counter to popular views about the ecological importance of fear in Yellowstone and elsewhere. "Although our study is the first to show how a prey animal uses predator downtime to flatten its landscape of fear, I suspect other examples will emerge as more researchers examine the intersection between prey habitat use and predator activity rhythms," says Kohl.

After 60 years, Isle Royale continues world's longest predator-prey study

IMAGE: 'After 60 years, the Isle Royale wolf-moose project continues. Today, wolves prosper again in several regions of North America. But our relationship with wolves in many parts of the world... view more 

Credit: Sarah Bird/Michigan Tech

Researchers from Michigan Technological University have released the annual Winter Study report detailing updates on the ecology of Isle Royale National Park. For the third year in a row, the Isle Royale wolf population remains a mere two, while the moose population continues to stay above the historic average. Without the pressure of predation, the expanding moose population will have a greater impact on the island's forest ecology.

The study co-authors include Research Professor Rolf Peterson, Professor John Vucetich and Assistant Research Professor Sarah Hoy. They say the heart of the study's success has been the more than 1,000 citizen science volunteers who have bolstered the study's fieldwork efforts in small teams totaling about 40 people each year for the last 30 years. Together, they helped gather enough skulls to document the shrinking moose of Isle Royale, observe seasonal wolf activity and earned more than their fair share of hiking boot blisters.

In terms of population trends, little changed on the island this past year. As Peterson, Vucetich and Hoy write in the report about the last male-female pair of wolves, "there was no evidence of any change in their status, except they are older by a year."

The pair are closely related--both as siblings and as father-daughter--and the inbreeding within the island's isolated wolf population is what contributed to their demise. The wolves' numbers started plummeting in 2009, declining by 88 percent from 24 to 2 wolves for that period; historical levels of wolves typically varied between 18 and 27. The pair, aged eight and ten years old, may have produced a pup several years ago but the female has continued to reject the male as a mate.

One meager hope for new wolves formed briefly in early February. For almost a week, an ice bridge connected the island to the Ontario mainland. However, the ice conditions were rough, the bridge did not last long, and the researchers found no evidence of wolves crossing over. With fewer ice bridges and warmer winters, the chances of wolves recovering naturally is slim to none.

As the wolf population declined and forage remained abundant, the moose population has been able to expand. Counting conditions for the past two winters have not been ideal, but the team estimates the moose population to be around 1,475 members. The population usually numbers between 700 and 1,200 moose. Hoy, who led the skull size study of the island's moose that found their size decreased by 16 percent over 40 years, says we are observing a population in transition.

"Although the effects on body size are quite subtle, there was a marked decline in lifespan over the study period," she says, explaining that wolves are not the only factor affecting moose. The changes in both populations impact the rest of the island, particularly balsam fir, which is a staple winter food for moose. "Maybe the trees can withstand one major source of stress, but with the lack of predation and a changing climate, can it withstand two or more?"

Peterson, who has been a part of the Isle Royale research for the past 50 years, says the island is a unique place to study moose and wolves. Unlike big, complex spaces like Yellowstone, where the cascading effects of wolf populations are still debated among scientists, Isle Royale is a neatly contained ecosystem that can provide insight into other Northwoods settings.

"This is the perfect environment to observe predator-prey interactions--but doesn't make it easy," he says. "We anticipate big things are about to happen, with wolf predation restored, that will once again change the direction of the island's ecosystem. It might take a long time to see the full impact of those changes."

The National Park Service has proposed introducing 20-30 wolves to the island over the next three years. The final environmental impact statement was completed and the identified preferred alternative is to restore wolf predation, but the final decision on the plan is pending as of the Winter Study report publication.