Shrinking sea ice is creating an ecological trap for polar bears

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San Diego Zoo Global researchers studying the effects of climate change on polar bears are using innovative technologies to understand why polar bears in the Southern Beaufort Sea are showing divergent movement patterns in the summer. In recent decades, about a quarter of this population of bears have chosen to come on land instead of staying on the shrinking summer sea ice platform. Historically, the polar bears in this region remained on the ice year-round. The decision of each individual bear to stay on the ice or to move to land appears to be linked to the energetic cost or benefit of either option, and the potential of having to swim to reach land.

"We found that bears who moved to land expended more energy on average during the summer than bears that remained on the receding sea ice," said Anthony Pagano, Ph.D., a postdoctoral research fellow co-mentored between San Diego Zoo Global, the U.S. Geological Survey and Polar Bears International. "And in the late summer, as the ice became even more restricted, a greater percentage of energy was expended by bears swimming to land. This means the immediate cost of moving to land exceeded the cost of remaining on the receding summer pack ice -- even though bears are having to move greater distances to follow the retreating sea ice than they would have historically."

However, prior research has shown that bears on land in this region have access to whale carcasses in the summer, while bears on the sea ice appear to be fasting. Researchers are concerned that the decision by each individual bear to stay on the ice is creating an ecological trap that may be contributing to population decreases that have already been documented in this population.

The Southern Beaufort Sea subpopulation of polar bears has experienced increased sea ice retreat in recent decades. A basic understanding of polar bear energetics that can be applied to this research has come from studies that include polar bears at the San Diego Zoo and at the Oregon Zoo.

"The polar bear conservation program at the San Diego Zoo has supported research such as this by engaging in studies to measure the energetic costs of polar bear metabolism," said Megan Owen, Ph.D., director of Population Sustainability, San Diego Zoo Global. "These studies have enhanced the capacity of field researchers to interpret data collected on free-ranging bears, providing a better understanding of what it costs a polar bear to move about their rapidly changing habitat."

"The research underscores the importance of taking action to reduce the greenhouse gas emissions that are causing sea ice to melt," said Steven Amstrup, Ph.D., chief scientist at Polar Bears International. "It's yet another piece in the climate puzzle, showing the impacts of global climate warming on polar bears and how the bears are responding to sea ice retreat."

Himalayan wolf discovered to be a unique wolf adapted to harsh high altitude life

The Himalayan wolf is considered an ancient wolf as it evolved prior to the contemporary grey wolf which is found in large parts of North America and Eurasia. Very little is known about the Himalayan wolf, because science and conservation have overlooked these high-altitude wolves as just another grey wolf until recently. As a result, very little research had been conducted on this wolf and no conservation action has been in place, risking a silent population decline of this wolf. This research, published today in the Journal of Biogeography, reveals this wolf's evolutionary uniqueness based on many different genetic markers; including a genetic adaptation to cope with the high-altitude environment, which is an adaptation that is not found in any other wolf. The Himalayan wolf is a top carnivore in the Asian high-altitudes, which hold some of the last intact large wilderness areas on our planet. The protection of the Himalayan wolves is critical to preserve these ecosystems given that top carnivores are key to keep an ecosystem healthy and balanced. This becomes even more relevant when considering that the Asian high-altitudes hold the water resources for billions of people in south-east Asia and it is of global interest to keep those ecosystems and their wildlife populations healthy.

The insights gained in this research by scientists at the University of Oxford's Department of Zoology further inform the development of long-term sustainable conservation plans for these wolves and their high-altitude ecosystems.

Lead researcher, Dr Geraldine Werhahn of WildCRU, Department of Zoology, says: 'The outcome of this research is absolutely astonishing. When we started out in 2014 it was surprising how little was known about these wolves inhabiting a relatively large region of our planet. At the time the scarce data available was indicating a genetic difference, but we had no explanation for why these wolves are different from a grey wolf.'

'Now we know that these wolves are different from genetics to ecology, and we have an indication of what the reason may be: the evolutionary fitness challenge posed by the low oxygen levels in the extreme high altitudes. When we started this research we thought this wolf is found only in the Himalayas, but now we know that they are found in the entire high altitude regions of Asia comprising the habitats of the Himalayas and the Tibetan Plateau. Much still remains to be revealed about their ecology, behaviour and population size. But the time to protect them is now!'

The researchers observed where the wolves chose their den sites and found that in Nepal the Himalayan wolf pack sizes are on average five animals and hence smaller than usual grey wolf packs. These insights into the wolves' social life combined with observations on the livestock herding practices in these high-altitudes helps to identify areas of immediate conflict between herding and wolf pup rearing and propose mitigation action. The researchers observed exclusive denning behaviour of Himalayan wolves and their pups.

The studies used wolf scat sampling for genetic and genomic research to understand their evolutionary history based on a wide array of different genetic regions. It also used the scats for a dietary study, investigating what prey species the wolves and other carnivores have eaten. The researchers studied which prey species and at which amount were eaten by the wolves and compared that to the abundance of these same prey species in the landscape to understand what the wolves had available and what they have actually taken.

The researchers found that the Himalayan wolf use more wild prey species than livestock when considering their availability and identified the main prey species for the Himalayan wolf. Livestock is seasonally often more abundant in the habitats than wild prey species, which poses two problems. Firstly, the wolves encounter much more livestock than wild prey. Secondly, livestock competes with wild prey for food and space and often displaces wild prey species. As a result, the wolves are left with little choice but to kill livestock. This is a key finding for developing conservation action for the Himalayan wolf, with solutions being to restore and protect wild prey populations and working towards sustainable livestock herding practices.

The main conservation threats appear to be the killing of wolves to retaliate livestock depredation, as well as for selling body parts in the flourishing illegal wildlife trade. Livestock is a major livelihood of many local communities in these harsh high-altitude environments, and losses of livestock has serious financial consequences for people. Improving livestock protection and sustainable management can mitigate depredation conflict substantially. Illegal wildlife trade involves many wildlife species found in these high-altitude regions, with the animal parts often traded for high prices. This illegal wildlife trade needs to be drastically combated from political to ground level across the countries to the benefit of many wild species.

In addition, a social survey study with local communities helps to understand what people want and need to be able to commit to wildlife protection in these regions.

Local people expressed the wish to be closely involved in conservation work. Community conservation groups have proven successful in Himalayan areas.

These research findings can now be used as data basis to formerly recognize the Himalayan wolf as an own wolf taxon (giving it a scientific (Latin) name). This formal taxonomic recognition paves the way to assign it an IUCN conservation status. These are the two pivotal steps now required to advance the conservation of these wolves and their habitats.

With these fundamental researches now accomplished, moving forward research is planned to explore behavioural and more detailed ecological aspects around these wolves, while also piloting a conservation action plan with the local communities to develop a plan for the Himalayan wolf that shall be applicable across the Himalayan region in the long term.

Grizzlies Saved: Judge rules Trump administration unlawfully removed federal protections

Grizzly 610 walks down a park road with her three cubs in springtime, April 13, 2012.

Photo courtesy of Thomas D. Mangelsen

This is a victory for the bears and for people from all walks of life who come to this region to see the grizzly in its natural place in the world.

Timothy Preso

Managing Attorney, Earthjustice

September 24, 2018

Missoula, MT — Federal safeguards for Greater Yellowstone Ecosystem grizzly bears were reinstated today, after a judge ruled that the Trump administration’s decision to strip Endangered Species Act protections from the population was illegal.
The decision spares the grizzlies from a planned trophy hunt scheduled to begin this fall in Wyoming and Idaho. Earthjustice, representing the Northern Cheyenne Tribe, Sierra Club, Center for Biological Diversity and National Parks Conservation Association, argued for restoring protections to Yellowstone grizzly bears.

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“The grizzly is a big part of why the Yellowstone region remains among our nation’s last great wild places,” said Earthjustice attorney Tim Preso, who argued the case. “This is a victory for the bears and for people from all walks of life who come to this region to see the grizzly in its natural place in the world.”
“The Northern Cheyenne Nation views the grizzly bear as a relative entitled to our respect and protection from harm,” said Lawrence Killsback, President of the Northern Cheyenne Nation. “We have a responsibility to speak for the bears, who cannot speak for themselves. Today we celebrate this victory and will continue to advocate on behalf of the Yellowstone grizzly bears until the population is recovered, including within the Tribe’s ancestral homeland in Montana and other states.”
“We’re glad the court sided with science instead of states bent on reducing the Yellowstone grizzly population and subjecting these beloved bears to a trophy hunt,” said Bonnie Rice, Senior Representative for Sierra Club’s Our Wild America Campaign. “Changing food sources, isolation, inadequate state management plans and other threats that grizzly bears continue to face warrant strong protections until they reach full recovery.”
“People around the world will applaud the decision to again protect Yellowstone’s beloved grizzly bears under the Endangered Species Act,” said Andrea Santarsiere, a senior attorney with the Center for Biological Diversity. “Facing ongoing threats and occupying a fraction of their historic range, grizzly bears are nowhere near recovery. These beautiful and beleaguered animals certainly shouldn’t be shot for cheap thrills or a bearskin rug.”
“Grizzly bears that call Grand Teton and Yellowstone National Parks home will no longer be threatened by an aggressive hunt that was planned this fall on lands bordering the national parks, thanks to the court’s ruling,” said Bart Melton, Northern Rockies regional director for National Parks Conservation Association. “The Department of the Interior can now go back to the drawing board to hopefully consider what research, such as the long-term impacts of climate change on the population, must be considered to ensure a healthy long-term future for Greater Yellowstone Ecosystem grizzlies.”
Read the court decision.

Background

In August 2017, the U.S. Fish and Wildlife Service removed the Yellowstone-region grizzly bear population from the federal endangered and threatened species list, even though the area’s grizzly population has suffered high levels of human-caused deaths in recent years.
This fall, for the first time in more than 40 years, the states of Wyoming and Idaho announced grizzly hunts that would have allowed for up to 23 bears to be killed outside of Yellowstone National Park. Today’s court ruling blocked the hunts. The court had previously issued an extended a temporary restraining order to prevent the hunt from proceeding while the judge finalized his decision.
The Northern Cheyenne Tribe and conservation groups challenged the Fish and Wildlife Service’s disregard of bear deaths following the bears’ recent shift to a more heavily meat-based diet following the loss of other foods.
The tribe and groups also faulted the Service for carving out and delisting the isolated Yellowstone grizzly population instead of focusing on a broader, more durable grizzly recovery in the West. They further challenged the Service’s decision to disallow public input on changes to its management framework for grizzlies, which weakened protections.
Learn more about the legal fight.

Dogs and wolves are both good at cooperating

Basic cooperation skills appear to be shared by dogs and wolves, suggesting that this ability was present in a common ancestor and was not lost during domestication

Max Planck Institute for the Science of Human History

A team of researchers have found that dogs and wolves are equally good at cooperating with partners to obtain a reward. When tested in same-species pairs, dogs and wolves proved equally successful and efficient at solving a given problem. This finding suggests that basic cooperation abilities were present in a common ancestor of dogs and wolves, and have not been lost in the domestication process.
It is estimated that dogs were domesticated as much as 30,000 - 40,000 years ago, and over that span of time they have undergone many changes from their wild counterparts, wolves. In a study published in the Journal of Comparative Psychology, researchers tested dogs and wolves for the ability to coordinate their actions with a partner of the same species to obtain rewards. The wolves in the study were from Tierpark Petersberg and Wolfcenter Dörverden. The researchers from the Max Planck Institute for the Science of Human History, the Max Planck Institute for Evolutionary Anthropology, and colleagues, found that dogs and wolves performed equally well on the task, suggesting that this ability was present prior to dogs' domestication in a common ancestor. The researchers hypothesize that, since dogs have been specifically selected for their ability and willingness to cooperate with humans, they might have an even higher success rate when humans are the cooperation partner.
The Test Scenario: Hunting large prey To test cooperation ability, the researchers created a test scenario that was designed to mimic a hunting situation, one in which multiple animals were trying to take down a larger herbivore, such as an elk or other horned prey. The concept was that, in the wild, one of the animals would need to draw the attention - and the dangerous horns - of the potential prey, so that the other could attack from the rear and bring the prey down. Thus the animal that took the most risk in the hunt also had to trust that it would be given a share of the reward in the end. The test apparatus involved a barrier separating the participants from a food reward, with two openings on opposite ends that were controlled by a researcher. When the first animal approached an opening, the door before it would shut while the opposite door remained open, allowing the partner to enter first and access the food. The door then remained open, so that other animal could then enter. Thus the animals had to cooperate in two ways - first by positioning themselves on opposite ends of the barrier and then by timing and coordinating their approaches towards the barrier.
The researchers found that the dogs and wolves were equally successful, succeeding in about three out of four trials on average. "Dogs were not outperformed by wolves in coordinating their actions, in the frequency of success or in how long the task took," explains Juliane Bräuer of the Max Planck Institute for the Science of Human History, lead author of the study and head of the DogStudies group at the institute. "This is somewhat surprising, as it contradicts recent findings by other researchers related to more complex cooperation tasks performed by dogs and wolves." The researchers hypothesize that this could be due to the simple nature of the task in the present study, which might require only basic cooperation skills.
Food sharing depends on the dynamics of the pair, not on species After solving the test, the pairs generally shared the food reward, but sharing was more likely when the dominant member of the pair was the second to arrive at the reward. "The probability of co-feeding during successful trials was higher when dominants 'took the risk,' so to speak, in moving first and drawing the closed door, because their higher rank gave them a higher chance to nonetheless get their share even if they accessed the food reward a few seconds after the subordinate," explains Bräuer. So while the researchers set out to test cooperation, it turned out that competition within the pair was also a factor.
Interestingly, however, dogs and wolves seemed to differ in which animal in the pair was willing to move first, drawing the closed door and thus being second to the food. Dominant wolves seemed to be more willing to take on this task in general than dominant dogs, and did so more frequently the more times the pair shared food. Dominant dogs, on the other hand, apparently seem to prefer to wait for their partner to draw the closed door. As would be expected, the more times dogs shared food, the more likely the subordinate member of the pair was to move first and draw the closed door.
More complex cooperation remains to be investigated The researchers point out that, although the kind of coordination shown in the present study may rely on more simple mechanisms than full, conscious cooperation, it can still inform us about how cooperative behavior might have changed - or not - during the domestication process. "Our results suggest that the abilities needed to coordinate actions were already present in the dog-wolf ancestor," notes Bräuer. "In future studies, it would be interesting to focus on the question of how exactly factors like social dynamics, living conditions, the type of task and maybe also breed differences influence the cooperative behavior of dogs and wolves."

The largest bears in the world use small streams to fatten up on salmon

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It's a familiar scene to anyone who's watched footage of brown bears catching sockeye salmon in Alaska: They're standing knee-deep in a rushing river, usually near a waterfall, and grabbing passing fish with their paws or jaws.

But a new study published in the journal Conservation Letters reveals a different picture of how and when bears eat salmon. Most of these bears, also known as grizzlies, are dipping into small streams to capture their iconic prey.
Using a foraging model based on the Wood River basin in southwest Alaska, a study team led by Oregon State University determined that while small-stream habitats have only about 20% of the available salmon in the watershed, they provide 50% of bear consumption of salmon.
"This tells us that populations of sockeye salmon that spawn in little streams are disproportionately important to bears," said study lead author Jonny Armstrong, an ecologist at Oregon State University. "Bears profit from these small streams because they offer salmon at unique times of the season. To capitalize on plentiful salmon runs, bears need them to be spread across time."
Small streams typically have cold water, which leads to populations of salmon that spawn much earlier in the season when no other populations are available to predators such as bears.
These results have potential consequences for how environmental impact assessments are conducted and evaluated for large projects such as the proposed Pebble Mine in Alaska's Bristol Bay.
These reports typically focus on how the project will affect the abundance of salmon in lakes and rivers, but they usually overlook smaller habitats, Armstrong said.
"When people want to build a large mine, they think these streams don't matter because they represent a small fraction a watershed, in terms of area or salmon abundance. In conservation and management, we generally place value on the largest runs of salmon at the expense of the smallest ones," Armstrong said. "If we pose a different question and ask which habitats are important for the ecosystem, then small streams become particularly relevant."
The researchers developed a mathematical model that explores how watershed development and commercial fisheries affect how many sockeye salmon are available to grizzlies. The model simulated different patterns of development and explored how they affected the number of salmon bears consumed.
Protecting large salmon runs at the expense of smaller ones turned out to be bad for bears.
"This causes the bears' total salmon consumption to drop off faster compared to strategies that protected small salmon runs and the early feeding opportunities they offer to bears," Armstrong said. "If you impair these areas, you may only reduce the total number of salmon by a little, but the number of salmon that end up in bear's stomachs -- you could reduce that a lot."
According to the study authors, there are two significant reasons why the largest bears in the world are drawn to small streams to eat salmon.
First, the fish in these streams are easy to catch for adult and juvenile grizzlies. And second, because the water is colder than in lakes and rivers, salmon spawn in them earlier -- probably to give their eggs more time to incubate, the authors said. So, the fish are plentiful by the first week of July -- making them the first places bears fish after they emerge from hibernation.
"When they come out of hibernation, the bears are just scraping by and barely making it," Armstrong said. "Having these streams means they can start eating salmon in early July, which is about six weeks before the river- and lake-salmon populations start spawning and become available to bears. It's an incredible foraging opportunity for bears."
Armstrong added, "I'm sure that native Alaskans who subsisted on salmon were keenly aware of this, too."

Habitat restoration alone not enough to support threatened caribou

Other conservation methods may also be needed until restored sites are more established

University of British Columbia

IMAGE: New UBC research suggests restoring habitat may not be enough to save threatened woodland caribou--an iconic animal that's a major part of boreal forests in North America and a key... view more 

Credit: UBC Faculty of Forestry

New UBC research suggests restoring habitat may not be enough to save threatened woodland caribou--an iconic animal that's a major part of boreal forests in North America and a key part of the culture and economy of many Indigenous peoples in Canada.
Caribou populations have declined rapidly in recent decades across much of western Canada, including the oil sands region of northeastern Alberta. The researchers placed hidden cameras, known as "camera traps", in the area to see if replanting seismic lines has helped protect caribou by separating them from predators and fellow prey moving through the area.
Seismic lines, which are narrow strips of land cleared to make way for oil and gas exploration, are thought to disturb caribou habitat and promote faster travel for predators and food competitors. These lines do not recover quickly naturally, but are now being restored through replanting with native trees and natural features like mounds and tree debris.
"In theory, restoration should have made it much more difficult for predators to travel across the caribou range, but our cameras showed us a different picture," said lead author Erin Tattersall, who did the work as a master's student in forest sciences at UBC.
Predators like black bears and wolves, and prey like moose, used the restored seismic lines about as much as they used unrestored lines. Only white-tailed deer--a key caribou competitor --showed less use of the restored lines. Caribou preferred to use lines located in low-lying wetland areas, as well as more isolated lines--whether they'd been restored or not.
"In other words, restoration did not do much to keep caribou apart from their predators and competitors, at least not in the short term," Tattersall said.
The work, published last week in Biological Conservation, is one of the first to challenge the assumed impacts of a caribou recovery strategy, and researchers say it makes the case for more rigorous analysis of conservation methods.
"It's possible caribou will eventually recover in the area we studied, and other restoration approaches in other regions could also prove more immediately effective for caribou recovery," said senior author Cole Burton, a professor of forestry who leads the Wildlife Coexistence Lab at UBC. "But our results clearly show that we can't simply assume the best--it's necessary to closely monitor the actual results of restoration."
And while the study focuses on Alberta caribou, it can also be important for discussions on saving B.C. caribou, Burton added.
"We are seeing steep declines in many of B.C.'s caribou populations, and even total losses of some," he said. "Effective restoration of already degraded habitats will ultimately be critical to recovering our caribou."

What wolves' teeth reveal about their lives

IMAGE: Biologist Blaire Van Valkenburgh has spent more than three decades studying the skulls of large carnivores. Here she displays a replica of a saber-toothed cat skull. At left are the... view more 

Credit: Christelle Snow/UCLA

UCLA evolutionary biologist Blaire Van Valkenburgh has spent more than three decades studying the skulls of many species of large carnivores -- including wolves, lions and tigers -- that lived from 50,000 years ago to the present. She reports today in the journal eLife the answer to a puzzling question.
Essential to the survival of these carnivores is their teeth, which are used for securing their prey and chewing it, yet large numbers of these animals have broken teeth. Why is that, and what can we learn from it?
In the research, Van Valkenburgh reports a strong link between an increase in broken teeth and a decline in the amount of available food, as large carnivores work harder to catch dwindling numbers of prey, and eat more of it, down to the bones.
"Broken teeth cannot heal, so most of the time, carnivores are not going to chew on bones and risk breaking their teeth unless they have to," said Van Valkenburgh, a UCLA distinguished professor of ecology and evolutionary biology, who holds the Donald R. Dickey Chair in Vertebrate Biology.
For the new research, Van Valkenburgh studied the skulls of gray wolves -- 160 skulls of adult wolves housed in the Yellowstone Heritage and Research Center in Montana; 64 adult wolf skulls from Isle Royale National Park in Lake Superior that are housed at Michigan Technological University; and 94 skulls from Scandinavia, collected between 1998 and 2010, housed in the Swedish Royal Museum of Natural History in Stockholm. She compared these with the skulls of 223 wolves that died between 1874 and 1952, from Alaska, Texas, New Mexico, Idaho and Canada.
Yellowstone had no wolves, Van Valkenburgh said, between the 1920s and 1995, when 31 gray wolves were brought to the national park from British Columbia. About 100 wolves have lived in Yellowstone for more than a decade, she said.
In Yellowstone, more than 90% of the wolves' prey are elk. The ratio of elk to wolves has declined sharply, from more than 600-to-1 when wolves were brought back to the national park to about 100-to-1 more recently.
In the first 10 years after the reintroduction, the wolves did not break their teeth much and did not eat the elk completely, Van Valkenburgh reports. In the following 10 years, as the number of elk declined, the wolves ate more of the elk's body, and the number of broken teeth doubled, including the larger teeth wolves use when hunting and chewing.
The pattern was similar in the island park of Isle Royale. There, the wolves' prey are primarily adult moose, but moose numbers are low and their large size makes them difficult to capture and kill. Isle Royale wolves had high frequencies of broken and heavily worn teeth, reflecting the fact that they consumed about 90% of the bodies of the moose they killed.
Scandinavian wolves presented a different story. The ratio of moose to wolves is nearly 500-to-1 in Scandinavia and only 55-to-1 in Isle Royale, and, consistent with Van Valkenburgh's hypothesis, Scandinavian wolves consumed less of the moose they killed (about 70%) than Isle Royale wolves. Van Valkenburgh did not find many broken teeth among the Scandinavian wolves. "The wolves could find moose easily, not eat the bones, and move on," she said.
Van Valkenburgh believes her findings apply beyond gray wolves, which are well-studied, to other large carnivores, such as lions, tigers and bears.
Extremely high rates of broken teeth have been recorded for large carnivores -- such as lions, dire wolves and saber-toothed cats -- from the Pleistocene epoch, dating back tens of thousands of years, compared with their modern counterparts, Van Valkenburgh said. Rates of broken teeth from animals at the La Brea Tar Pits were two to four times higher than in modern animals, she and colleagues reported in the journal Science in the 1990s.
"Our new study suggests that the cause of this tooth fracture may have been more intense competition for food in the past than in present large carnivore communities," Van Valkenburgh said.
She and colleagues reported in 2015 that violent attacks by packs of some of the world's largest carnivores -- including lions much larger than those of today and saber-toothed cats -- went a long way toward shaping ecosystems during the Pleistocene.
In a 2016 article in the journal BioScience, Van Valkenburgh and more than 40 other wildlife experts wrote that preventing the extinction of lions, tigers, wolves, bears, elephants and the world's other largest mammals will require bold political action and financial commitments from nations worldwide.
Discussing the new study, she said, "We want to understand the factors that increase mortality in large carnivores that, in many cases, are near extinction. Getting good information on that is difficult. Studying tooth fracture is one way to do so, and can reveal changing levels of food stress in big carnivores."