Wildlife tracking technology delivers promising results on polar bears

 

 Studying polar bears just became a lot easier with new “burr on fur” trackers which confirmed scientists’ belief that subadult and adult males spend most of their time on land lazing around, conserving energy until the ice returns.

A multi-institutional research team led by York University and including the University of Alberta, Environment and Climate Change Canada, Manitoba Sustainable Development, Ontario Ministry of Natural Resources and Forestry, and Polar Bears International, used three different “burr on fur” prototypes to study their effectiveness.

The paper, “Telemetry without collars: performance of fur- and ear-mounted satellite tags for evaluating the movement and behavior of polar bears,” published in the journal Animal Biotelemetry, details the first peer-reviewed examination of these new tracking devices that adhere to the fur of polar bears.

Studying polar bears is a difficult feat with current radio collars only suitable to be used on female bears leaving out a swath of the population, but new technology is providing researchers with a new tool which has confirmed the behaviour of adult male polar bears while on land waiting for the ice to form again.

Efforts to develop less-invasive tracking options and tools that could work on polar bears of both sexes and nearly all ages have been ongoing for years with varying success. Collars have been and remain the primary means of studying polar bear movements. More recently, ear tag transmitters have been used as a lighter-weight alternative. While both technologies serve an important role in helping study and conserve polar bears, researchers continually strive to develop methods that are both minimally invasive and provide quality data.

This led to a new tracking initiative known as “Burr on Fur,” which began as a challenge from Polar Bears International to 3M scientists, the global science and manufacturing company behind Post-It notes, to create a temporary, simple method for affixing small tracking units to polar bear fur. Three “Burr on Fur” prototypes were recently tested on wild polar bears along the coast of Hudson Bay, Canada, alongside traditional ear tag transmitters.   

The shortcomings with traditional tracking methods: The ear tag and “Burr on Fur” devices fill an important niche for scientists and wildlife managers. The new tags allow researchers to follow the movements of adult male and subadult polar bears, two groups that can’t be studied using traditional satellite collars. Adult males can’t wear collars because they slip off their cone-shaped necks and heads, and subadult bears grow too rapidly for safe collar use. Traditional ear tags are an alternative to collars. However, they currently require recapture to remove and, although rare, can pose a risk of injury to the ear. The new Burr on Fur tags are designed to be temporary, minimally invasive, and can be applied to both sexes and nearly all ages of polar bears.

“Successfully attaching telemetry tags to polar bear fur has never been done before, and we’re excited to share the results of this innovative work,” said Tyler Ross, lead author of the paper and researcher at York University, “The fur tags showed great promise, and give researchers the ability to study the behaviors and movements of polar bears that we have very little data on, like subadult and adult male bears.”

The study: 58 wild bears were tagged using ear tags and three distinct fur tag designs to compare both the duration of time the tags remained active while attached to the bears and the accuracy of the trackers. Applied alongside a traditional ear tag, which relied on an Argos Transmitter, the three fur tags were:

• The Pentagon Tag: this five-sided device included five holes punched into its corners, allowing tufts of fur to be pulled through. It utilized an Argos Eartag Satellite Transmitter.
• The SeaTrkr Tag: an oval-shaped tag that had 10 holes punched to allow 10 fur-tuft attachments. This design used an Iridium-linked Telonics GPS SeaTrkr-4370 transmitter.
• The Tribrush Tag: a triangle tag outfitted with tubes along its borders, through which pipe brushes ensnared the fur, twisting it inside the tubes. This tag used the same Argos transmitter as the Pentagon tags.

The research took place from autumn 2016 to 2021 with bears handled near Churchill, Canada, by the Polar Bear Alert Program and researchers at the University of Alberta, supplemented with operations by researchers at Environment and Climate Change Canada, Ontario Ministry of Natural Resources and Forestry, York University, and Manitoba Sustainable Development in 2021-22 near the Manitoba-Ontario border.

“Our results are an important step in better understanding the movements and behavior of polar bears, especially adult male bears, which are difficult to track because they can’t be fitted with satellite collars. Temporary, fur-mounted tags could also help track the movements of bears relocated after potentially coming into conflict with people, making these tags an important tool for conserving polar bears and keeping northern communities safe,” says York University Associate Professor and Sustainable Environmental Management Coordinator Gregory Thiemann, the report’s co-author.

Results: The top-performing fur tag was the SeaTrkr Tag, which remained attached to the bears for an average of 58 days and had superior accuracy due to its use of GPS/Iridium technology. In second place, the Trishbrush Tags remained attached for an average of 47 days. However, for the Tribrush Tag, the times varied widely, with one falling off after only two days while another lasted 114 days – the longest of all the tags.

Because they are permanently attached to the bears’ ears, the traditional ear tags remained in place for 137 days on average, while the shorter-term fur-based trackers proved to be reliable for shorter periods. The fur tags proved useful for monitoring bear behavior, and show great promise for future use in tracking polar bears, especially those that must be relocated after approaching too close to communities. Further testing and refinement are also being conducted on bears in zoos and aquariums through Polar Bears International’s Arctic Ambassador Center zoo and aquarium partners, allowing researchers to further refine the designs and see how they perform throughout different seasons. In the most recent round of zoo testing, a refined tag stayed on a bear for 75 days.

Important Data about Male and Subadult Polar Bears: The new data adds to our growing understanding of subadult and adult male polar bear movements and behaviors, which have been historically understudied because they cannot be safely collared for long periods. Findings confirm that adult and subadult male bears reduce their activity while on land, consistent with prior studies that showed bears spent approximately 70 to 90 per cent of their time resting during the ice-free period in Hudson Bay.     

Implications: While the ear tags remained attached to the bears longer, the temporary and easily affixed fur tags give scientists a new tool for enhanced tracking of bears for purposes of both applied research and managing human-bear interactions. The tracking tech could be applied to other types of bears, supporting efforts to reduce human-bear conflict, and future applications could include testing on other species with fur. While traditional tracking methods, such as collars, will remain critical for longer-term studies, the fur tags will prove a valuable tool, particularly for understanding and managing increasing wildlife-human interactions as the climate warms. 

“The collaboration between Polar Bears International, 3M, academic institutions, and governmental partners is a testament to our commitment to improving Arctic wildlife research and conservation technology,” says Geoff York, Senior Director of Research and Policy at Polar Bears International, adding, “These advancements will have tangible implications for wildlife management, aiding in tracking polar bears and promoting improved human-bear coexistence. We’re eager to further refine and deploy this pivotal technology.” 

About Arctic Sea Ice Day: These findings publish on July 15, which is Arctic Sea Ice Day, an annual event created by Polar Bears International to spark actions and conversations about the rapidly melting Arctic ecosystem, including its global significance and how people can help slow this warming trend. The Arctic is now warming nearly four times faster than the rest of the planet, causing the sea ice to melt, which causes polar bears to spend longer periods fasting on land.

Polar Bears International invites people to access the full report and urges the scientific community to consider the implications of these findings for further research and application in conservation and coexistence efforts.

Wolves’ return has had only small impact on deer populations in NE Washington

 

Peer-Reviewed Publication

 

IMAGE: 

THE NEW STUDY FOCUSED ON THE WASHINGTON PREDATOR-PREY PROJECT’S STUDY AREA IN NORTHEAST WASHINGTON, SHOWN IN GREEN.

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CREDIT: TAYLOR GANZ

FROM: James Urton

(Note: researcher contact information at the end)

Humans drove wolves to extinction in Washington state around the 1930s. Thanks to conservation efforts, by about 80 years later, wolves had returned — crossing first from the Canadian border into Washington around 2008 and later entering the state from Idaho. Since then, wolf numbers in Washington have been steadily growing, raising questions about what the return of this large predator species means for ecosystems and people alike.

In northeast Washington, where wolves have recovered most successfully, researchers from the University of Washington and the Washington Department of Fish and Wildlife tracked one of their primary prey — white-tailed deer — in part to see what impact wolf packs are having on deer populations. The answer? So far, wolves aren’t having as much of an impact on deer as other factors.

In a paper published June 18 in Ecological Applications, the team reports that the biggest factors shaping white-tailed deer populations in northeast Washington are the quality of habitat available and a different, long-established large predator in the state: the cougar, also known as the mountain lion or puma. Wolves were a distant third in their impact.

“A big take-away from this study is that wolves are not returning to empty landscapes. These are places with humans and other carnivore species, like cougars, which will affect the impact that wolves can have,” said lead author Taylor Ganz, who conducted this research for her UW doctoral degree as part of the Washington Predator-Prey Project. “This area has a relatively high human footprint compared to other areas where wolves have been studied. These are not national parks or dense, old-growth forests. They are areas with active logging, farming, ranching and towns. Our findings show that these factors are likely limiting the impact of wolves on one of their primary food sources.”

It's not that wolves aren’t preying on white-tailed deer. According to the study, they are, just not enough to take a large bite out of the population as a whole.

White-tailed deer are widespread east of the Cascades. The state’s highest-density population of this species lies within the study area, which includes farmland and timber forests in parts of Stevens and Pend Oreille counties in northeast Washington. For the study, researchers radio-collared 280 white-tailed deer, 14 wolves, 50 cougars, 28 coyotes and 33 bobcats from 2016 to 2021. At the time of collaring, the researchers also noted vital statistics, including body condition, age and whether females were pregnant. When collared animals died, the team conducted a mortality investigation, if possible, and attempted to determine the cause of death.

The team, which also includes researchers with Washington State University and the Spokane Tribe of Indians, used the resulting dataset to estimate the growth rate of the white-tailed deer population over the four-year study, and to identify the major factors shaping it. The analysis determined that the white-tail population in the study area was likely stable, or slightly declining, but that wolves were not largely responsible.

The biggest factor impacting the deer population was habitat quality, including the amount of forage available for deer. For white-tailed deer, which are highly adaptable to human activity, foraging sites can range from forests and shrublands to agricultural fields. The study area includes both agricultural land and forests recently harvested for timber, both of which could provide deer with high-caloric density foraging sites, according to Ganz.

After habitat quality, the study found that predation by cougars had a smaller effect on the white-tailed population. Wolf predation had a still smaller impact. Bobcats and coyotes — both medium-sized predators — had a negligible impact on deer numbers.

“Studies like this provide valuable insights about the complexity of these systems and how managing predator and prey populations is challenging and dynamic,” said co-author Melia DeVivo, a research scientist with the WDFW. “It’s important to continue evaluating these systems to understand the impacts of management decisions. Prior to this study, one might have expected that relying solely on wolf management strategies would result in a booming deer population, when it is clearly more complex than that.” 

Since their return, the number of wolves in Washington has risen steadily, reaching a minimum of 260 in 2023, according to state researchers. Four wolf packs reside in the northeast Washington Predator-Prey Project study area. The total number of wolves in the study area — about 23 — remained steady overall during the research period.

The team’s findings contrast with studies of long-established wolf populations in protected areas, like Yellowstone National Park, which show a higher impact of wolves on the population dynamics of their prey species. To the authors of this new study, those differences highlight the importance of studying wolves in a variety of habitats.

“This study reminds us that the population dynamics of predator and prey species can vary quite a bit,” said senior author Laura Prugh, a UW associate professor of environmental and forest sciences. “Habitat quality, the species that are present and the degree of human activity all affect the impact that large predators like wolves will have. It’s critical to compare different types of sites.”

The paper is part of the Washington Predator-Prey Project, a partnership between the UW and the WDFW to investigate the impact of the wolves’ return on state ecosystems. Additional co-authors are Sarah Bassing , a UW doctoral alum in environmental and forest sciences; Lauren Satterfield, a UW doctoral student in environmental and forest sciences; biologists Brian Kertson and Benjamin Turnock with the WDFW; Lisa Shipley, a professor at WSU; Savannah Walker and Derek Abrahamson, both biologists with the Spokane Tribe of Indians; Beth Gardner, a UW associate professor of environmental and forest sciences; and Aaron Wirsing, a UW professor of environmental and forest sciences. The research was funded by WDFW, the National Science Foundation, the Rocky Mountain Elk Foundation, and the UW College of the Environment.

HYENAS VS. LEOPARDS

 

Peer-Reviewed Publication

 

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IMAGES FROM CAMERA TRAPS IN UDZUNGWA. FROM THE LEFT: FEMALE LEOPARD, HYENA, MALE LEOPARD

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CREDIT: RASMUS W. HAVMØLLER

Who’s stronger? A solitary leopard or cackle of hyenas? And which is best at getting along with humans?

University of Copenhagen researchers closely studied this in a large East African natural area surrounded by rural settlements. The study demonstrates that the presence of humans has a direct impact on the competitive relationship between the two large predator species: leopards (Panthera pardus) – the iconic spotted feline and the spotted hyena (Crocuta crocuta) – a kleptoparasite and pack hunter known for its comical appearance and characteristic 'laugh'.

"We humans continue eating our way into the little bit of wilderness left in the world. As we do, we impact wildlife. This study demonstrates that human disturbance upsets the balance between competing species and that this advantages hyenas," says Rasmus W. Havmøller, the study’s first author and a postdoc at the University of Copenhagen’s Natural History Museum of Denmark.

For months, Havmøller have been using camera traps to observe the dynamics between hyenas and leopards living in Tanzania’s Udzungwa Mountains – an approximately 2,000 km2 national park that is completely surrounded by agricultural and populated areas. The study is the first to combine camera observations of large predators over both time and space in a single analysis.

While the hyena as a species seems to be increasing in numbers, the population of leopards has been in significant decline for decades, both in Africa and worldwide. Since hyenas are the leopards' only competitor in this particular natural area, the ability of the two species to coexist is important for their survival. And here, the local population is an important factor:

"As the local people definitely don’t' like leopards, the leopards retreat as far away from humans as possible. Hyenas, on the other hand, benefit from the fact that humans don’t feel threatened by or pursue them. Consequently, hyenas live in close to human populations and may even exploit humans as shields against the leopards," says Havmøller.

"But the areas nearest to humans are also the areas with the most prey. And as hyenas assert dominance over these areas, it increases their ability to outcompete leopards and potentially threaten the leopard's adaptability," adds Havmøller.

Size matters

The researchers' observations confirm that size matters. While male leopards, which are larger, retain their dominance over hyenas, the situation is different for female leopards, which are smaller.

"Even though the male leopards are the ones in charge, the hyenas aren’t exactly scared off by them. They simply hang out in the background – probably to follow the leopards and steal their prey. But the physical inferiority of the hyenas seems to be compensated for in the areas closest to humans, because male leopards pull out," says Rasmus W. Havmøller, who continues:

"Female leopards, on the other hand, completely change their behavior when hyenas are in the area. They become diurnal, whereas hyenas are primarily nocturnal. This is probably because female leopards are smaller than hyenas, and that they will likely lose in any fight over prey."

Overall, the study shows that the hyenas benefit from living near humans.

"This suggests that the hyena's ability to adapt to areas of human activity may strengthen their overall success as a species and their competitive advantage over other large predators as we humans disturb more and more nature," says Havmøller.

When leopards are pressured, cascade effects may follow

According to the researcher, the shift in female leopard hunting patterns may have negative consequences:

"If you open up for more tourism and build more roads in the national park, the female leopards will be pressured immediately. They aren’t able to differentiate between safari tourists – who are most active during the day – and poachers. In time, they will probably learn that safari guests aren’t dangerous. But if there is a large and rapid influx into the area, you will probably see a decline in their population," says Rasmus W. Havmøller.

If leopards are seriously pressured out of the food chain, one should expect the emergence of what are known as cascade effects in the ecosystem:

"Plucking a large predator like leopards out of a food chain, which can be the ultimate consequence of human disturbances, may have very violent effects. Populations of other species, such as certain monkeys, whose populations are kept in check by leopards, will suddenly become too large and change the balance of the entire ecosystem," says the researcher.

As such, Havmøller hopes that the study will serve to encourage restraint when it comes to managing wilderness areas.

"Our results clearly indicate that human disturbances can change the competitive relationship between important predators. So, I hope that considerations will be made when expanding activities in wilderness areas, so as to roll them out slowly and give animals a chance to adapt. Furthermore, it would be good if the effects of human disturbances were monitored in more places using camera traps," concludes Rasmus W. Havmøller.

 

 

HYENAS VS. LEOPARDS 

• Leopards are unpopular among local people in many places because they may hunt livestock and attack humans. Hyenas, on the other hand, "clean up" by eating sick or dead livestock and don’t pose a problem for humans.
• Female leopards (approx. 20-43 kg.) are about half the size of male leopards (approx. 51-72 kg). Hyenas are in the middle in terms of weight (approx. 48-56 kg).
• Leopards are solitary hunters, whereas hyenas hunt in large cackles (clans), which can be an advantage for hyenas in confrontations with leopards.
• Hyenas are kleptoparasites that regularly steal the prey of other carnivores – including leopards.
• Leopards on the other hand, are masterful tree-climbers, which allows them to protect their prey from hyenas.