Watch: Tiny technology tracks Tucson bats

January 5, 2024 by The Wildlife Society

Each spring, lesser long-nosed bats (Leptonycteris yerbabuenae) make the journey from south and central Mexico to breed around Tucson, Arizona. Researchers are using a wildlife tracking system developed in Israel, and never before used in the United States, to better understand their foraging behavior. The Atlas system uses tiny radio transmitters glued to the bats’ backs, allowing researchers to track them through a network of antennas. 

Watch the video from the Arizona Game and Fish Department below.

Great Lakes wolves resilient to climate, land use change

January 4, 2024 by Joshua Rapp Learn

Wolf range in the Great Lakes region is unlikely to be negatively affected by projected human land use and climate change in the U.S. Great Lakes region.

“[The Great Lakes] wolf population is a good example of a conservation success story in the United States,” said TWS member Merijn van den Bosch, who received his PhD at Michigan State University investigating the spatial ecology of gray wolves.

While gray wolf (Canis lupus) populations have been expanding in the Great Lakes over the last four decades, van den Bosch and his colleagues wondered whether this success would last in the future.

For a study published recently in Ecosphere, they examined winter tracking surveys from the Great Lakes states that currently share a wolf population: Michigan, Wisconsin and Minnesota. The team collected data during the winters from 2017 to 2020 from surveys coordinated by the departments of natural resources of these three states.

Changing climate and development

The team then used future climate change prediction scenarios by the end of the 21st century: two in which the world keeps the rise in average global warming at about 3 degrees Celsius by reducing greenhouse gas emissions, and two other less sustainable futures in which the average global temperature increases by up to 5 degrees Celsius.

The researchers also examined socioeconomic projections parallel to the climate change predictions for the Great Lakes states as a way of understanding predicted land use change through 2100. That included a look at how landscape composition may change, leading to increases or decreases in forested areas, areas used for agriculture, or urban areas. All of these changes can affect suitable wolf habitat.

Future projections on land use change may favor wolves in some ways. Credit: Michigan State University/Michigan DNR

Resilient to change

The researchers found that wolf range in the Great Lakes region is likely to be resilient to both factors.

“Overall, it seems that wolf range in the Great Lakes is unlikely to be negatively affected by land use and climate,” van den Bosch said. In fact, under the most sustainable scenario, available wolf habitat may even expand by up to 35%, their models found, primarily due to increases in forest cover and decreases in areas used for agricultural activities.

Wolves aren’t particularly sensitive to climate, which may be one reason wolf habitat in the Great Lakes is expected to increase or at least remain stable—wolves are found in climates much warmer than the Great Lakes region.

“We expected that climate change throughout this century might not have a big impact when you consider where wolves live or have lived,” van den Bosch said, adding that today, they are found everywhere from India to the high Arctic.

Wolves are often resilient to climate change. Credit: Michigan State University/Michigan DNR

Land use change could restrict wolves in some areas due to increased agricultural activities and urban development, which not only provide less suitable habitat for wolves but also can form barriers to wolf movement. But overall, the land use changes predicted in parts of the Great Lakes won’t likely negatively affect wolves. Partly, this may be due to the projection that the amount of land used for agriculture may decline, resulting in increased forest cover.

Even in a less sustainable future where cities in those states increase up to 3%, no large losses of forest cover are expected in this region, and the amount of habitat available to wolves would remain stable. Van den Bosch said this worst-case scenario still isn’t that bad for wolves, as areas outside of cities that would be urbanized are already unsuitable for wolves, and 3% is a small fraction of the landscape.

These projections are parallel to the recent growth of wolves, which have far exceeded recovery targets set by the U.S. Fish and Wildlife Service when the species was listed under the U.S. Endangered Species Act in 1974, van den Bosch said. The current population of these three states is estimated at 4,200 wolves—far above the original recovery goals of 1,200 for Minnesota and 150 total for Wisconsin and Michigan. Great Lakes wolves now form the largest population in the contiguous U.S., he said.

Wandering Mexican wolf recaptured

January 4, 2024 by The Wildlife Society

Wildlife officials captured a Mexican wolf (Canis lupus baileyi) that wandered beyond the recovery area. It was the female wolf’s second venture outside the repopulation area. The New Mexico Game and Fish Department captured wolf F2754, nicknamed Asha, on Dec. 9, near the town of Coyote, N.M. She has been paired with another wolf in captivity in the hopes of increasing the population.

“By pairing her with a carefully selected mate in captivity, we are hoping she will breed and have pups this spring,” Brady McGee, a Mexican Wolf Recovery Coordinator for the U.S. Fish and Wildlife Service, told the Arizona Republic. “The best outcome for her is to be released back into the wild, where she and her offspring can contribute to Mexican wolf recovery.”

Read more from the Arizona Republic.

JWM: Despite predation, deer numbers in western Virginia are stable

January 3, 2024 by David Frey

In the Appalachian Mountains of western Virginia, hunters had noticed that as coyote and bear populations climbed in the region, white-tailed deer numbers were falling. That raised concerns that these carnivores were preying on young fawns, threatening the stability of a struggling population.

Yet when researchers looked into the effects of predators on the deer, they found that coyotes weren’t the biggest threat, and the deer population wasn’t at risk.

“The story that emerged was a little bit different than what was expected,” said Michael Cherry, Stuart W. Stedman Chair for White-tailed Deer Research at the Caesar Kleberg Wildlife Research Institute in Kingsville, Texas.

While white-tailed deer (Odocoileus virginianus) are thriving to the point of becoming a nuisance throughout much of the eastern U.S., in the southern and central Appalachians, deer populations are struggling. In a study published in PLOS ONE in August, researchers found that poor habitats and predation were driving down deer numbers in northern Georgia.

The deer population in Bath County, Virginia is also more vulnerable than some, and it’s one that state wildlife officials have been working to maintain to meet hunter demands.

“This has historically been a really popular place for hunters to go and pursue deer,” said Cherry, lead author of the recent study published in the Journal of Wildlife Management. “It’s a beautiful landscape with an abundance of public land on the George Washington National Forest.”

To find out how much predation was responsible for population declines, researchers used GPS collars and vaginal implant transmitters on 38 pregnant female deer. Once the animals gave birth, the team was able to find and collar 57 newborn fawns. If the collars stopped moving, researchers rushed to investigate how the animal it belonged to died. If they found a kill site, they searched for clues—scat, tracks, feeding behavior, sometimes even analyzing saliva left on the carcass—to determine what predator species was responsible.

The central Appalachians have a growing list of possibilities. Populations of coyotes (Canis latrans), bobcats (Lynx rufus) and black bears (Ursus americanus), are all on the rise. Yet the detective work proved pretty easy, Cherry said.

“Bears consume basically the whole fawn all in one sitting,” he said, and that was mostly what they found. Of the 57 fawns they collared, 37 died. Nine died from causes such as abandonment, malnutrition and disease. The other 28 were killed by predators, with bears responsible for nearly two-thirds of the predations. Bears killed 18 fawns. Bobcats killed five. Coyotes—whose growing numbers first raised concerns—killed just three.

Using that data, researchers were able to model the effects these predators had on the deer population. They found that, despite the predation, deer numbers were stable enough to allow for a modest increase in doe harvest.

The findings were not exactly a surprise, Cherry said. Adult female survival is much more important than fawn survival in driving population levels. And despite hunter concerns, the region is not very conducive to coyote populations.

While hunters were probably right in noticing that the deer were declining as coyotes were increasing, he said, the two probably weren’t related. Reduced forest harvesting that creates early successional habitat and irregular hard mast crops of acorns probably play the biggest roles.

“Overall, we think there has just been a decline in habitat quality for deer in the region,” Cherry said.

This article features research that was published in a TWS peer-reviewed journal. Individual online access to all TWS journal articles is a benefit of membership.  Join TWS now to read the latest in wildlife research. 

Concerns arise over American chestnut project

January 3, 2024 by The Wildlife Society

Efforts to return the American chestnut tree to the landscape have hit a stumbling block. Once a staple of forests throughout the eastern United States, the American chestnut (Castanea dentata) provided nuts for wildlife and humans, as well as wood for building, but at the beginning of the 20th century, a pathogen wiped out nearly all of the trees. For the past decade, researchers have been experimenting with genetic engineering to help the trees to survive the fungus. The method was promising, but this month the American Chestnut Foundation pulled its support from one of the efforts due to mounting concerns. Researchers plan to seek federal funding to continue with the program.

Read more from the Washington Post.

The December issue of the Wildlife Society Bulletin is now available

January 2, 2024 by The Wildlife Society

The Wildlife Society Bulletin is a benefit of membership in The Wildlife Society. Published four times annually, it is one of the world’s leading scientific journals covering wildlife science, management and conservation, focusing on aspects of wildlife that can assist management and conservation.

Join today for access to the Wildlife Society Bulletin and all the other great benefits of TWS membership.

Silver-haired bats produce identifiable songs consisting of repeated ultrasonic signals. These patterned sounds appear to be unique to this species and can be used to differentiate it from other bats. In a study in the December issue of the Wildlife Society Bulletin, researchers found that the songs may be part of mating behavior.

The December issue of the Wildlife Society Bulletin is now available. Credit: The Wildlife Society

Other articles look at waterfowl hunting participation, prairie-chicken translocations, shading marine turtle nests and more.

Log in to read the December issue today.

New Year’s Eve fireworks aren’t for the birds

January 2, 2024 by The Wildlife Society

The use of fireworks on New Year’s Eve can cause a massive flight response in birds, researchers found. Using data from weather radar and bird counts, an international team of researchers working in the Netherlands found an average of 1,000 times as many birds are in the area near fireworks displays as on other night. In some cases, the numbers peak up to 100,000 times the normal number. The effects are strongest within 5 kilometers of fireworks, but even 10 kilometers away, birds in flight are ten times normal. That’s particularly concerning, researchers say, because of the widespread use of fireworks across the country to celebrate the New Year. The displays cause “a flight response in birds of unprecedented scale, with immediate and lasting energetic consequences,” researchers concluded.

Read the study in Frontiers in Ecology and the Environment.

JWM: Reducing harvest regulations can boost male turkey numbers

December 29, 2023 by David Frey

As wild turkey populations decline in the southeastern United States, reducing harvest could help keep more male turkeys on the landscape.

Biologists have debated the impact of hunting on wild turkeys. Are more turkeys killed because of hunting? Or would the birds that hunters take home have been killed by predators, anyway?

In a study in the Journal of Wildlife Management, researchers studying eastern wild turkeys (Meleagris gallopavo silvestris) in the Southeast found male turkey survival is 30% higher in nonhunted populations.

That’s good news for managers looking for ways to bolster males in the population, said lead author Patrick Wightman, a research scientist at the University of Georgia, although how much more males would impact overall turkey populations isn’t clear.

“From a management perspective, one of the big takeaways is, if you’re wanting to increase male survival, you can decrease harvest,” said Wightman, who led the study as a postdoctoral researcher at the university. He hopes future research can shed light on how tight those restrictions would need to be to have a meaningful impact.

Wightman and his colleagues studied 860 male turkeys—some banded and some fitted with transmitters—in Georgia, Louisiana, North Carolina and South Carolina from 2014 to 2022 and created models based on their survival. In hunted populations, adult males had about a 50-50 chance of surviving in a year, Wightman’s team found. Annual survival among nonhunted turkeys was about 30% higher. Predation played little role.

To increase male turkeys on the landscape—and increase hunter satisfaction in the long run—managers may want to test different restrictions, including season length and bag limits, the researchers concluded.

“The vast majority of hunters are conservationists,” Wightman said. “If state agencies are taking away opportunities—whether it’s bag limits or season dates—I think the general public in the hunting community would be more supportive if they knew it would have some impact on survival.”

How much impact that would have on overall wild turkey survival is unclear, though. While turkey populations in much of the U.S. are thriving, in the Southeast, their numbers are tumbling. That’s probably due to a number of factors, Wightman said, but shrinking habitats and poorer habitat quality are probably most responsible, and hunting regulations haven’t taken into account those declines.

Wightman hopes the paper encourages managers to reconsider turkey harvest rates. In previous years when populations were thriving, 30% harvest rates were sustainable, but that’s probably not true anymore, he said, when fewer poults are reaching adulthood. “We’re making half the number of birds,” he said.

This article features research that was published in a TWS peer-reviewed journal. Individual online access to all TWS journal articles is a benefit of membership.  Join TWS now to read the latest in wildlife research. 

Technique simplifies disease sampling in wildlife

December 29, 2023 by The Wildlife Society

A new technique could help track disease in wildlife. In a study published in the Journal of Agricultural, Biological and Environmental Statistics, researchers proposed a way to reduce the sampling necessary to accurately measure how widely a disease has spread. The method is based on the notion that, since animals tend to cluster in groups, sampling a single individual can suggest whether or not the others are also infected. Using chronic wasting disease in deer as a case study, researchers found their approach reached similar conclusions to conventional methods. They hope an online application in development could help biologists figure out how many animals to sample. Researchers believe the technique can save biologists time and money.

“The framework is so flexible, we can use it for any animals,” said co-author Krysten Schuler, assistant research professor in the Department of Public and Ecosystem Health at Cornell University.

Read more from Cornell Chronicle.

Here are the top 10 wildlife stories of 2023

December 28, 2023 by The Wildlife Society

African oryx running wild in New Mexico. Snake reintroduction. Human shields and predators.

These are just some of the most popular news stories The Wildlife Society has published in 2023, covering the gamut of cutting-edge research on conservation, wildlife management, and the policies that affect our ecosystems.

The past year has seen the beginning of the implementation of wolf reintroduction to Colorado as well as a partisan divide that has affected the passage of some wildlife legislation. But wildlifers have nonetheless made great discoveries in furthering our understanding of ecology and wildlife populations management.

Here is the list of our top 10 most popular stories of 2023.

10. USFWS issues new Colorado gray wolf designation

The Colorado public opted to return gray wolves (Canis lupus) to the state in a 2020 ballot box vote. To help ease some of the regulatory restrictions on wildlife managers who will be working on the issue, the U.S. Fish and Wildlife Service issued a “nonessential experimental population” designation for the canids in Colorado. This will help ease potential human-wildlife conflicts as the project gets underway, the agency hopes.

9. What’s the best way to translocate snakes?

Massassauga rattlesnakes (Sistrurus catenatus) are listed as endangered in Canada due to habitat fragmentation and low numbers there. It’s been years since scientists have attempted to translocate the species. To learn more about the most successful practices in snake reintroductions, in general, one research team examined more than 100 translocation cases in an effort to better inform any future snake management actions to conserve the massassauagas.

8. JWM: Why has elk recruitment declined in New Mexico?

Elk recruitment has been declining for years in New Mexico. One recent study pointed the finger at predators as being a possible reason for these population drops. But new research shows that climate change may also be playing a major role.

7. 10 years later, translocated turtles find their way home

In 2010, an oil pipe operated by Enbridge Inc. burst into a tributary near the Kalamazoo River in Michigan. The resulting disaster affected a huge amount of wildlife in the area, including turtles. Researchers who had rehabilitated and translocated turtles away from the affected area returned a decade later to see if these turtles had moved back to the places where they were removed from.

6. TWS2022: Do cougars use artificial water sources to ambush prey?

Pumas have been observed killing deer around artificial drinking sources. Researchers wanted to know whether the big cats were cuing into these stations as good places to ambush their prey. They found that while they weren’t directly using the drinking sources, they might be following ungulates to the general areas around them.

5. Window decals create sticky situation for deterring bird strikes

Window decals can sometimes be effective ways to keep birds from smashing into them. But researchers found their success is all about placement. Many people put them on the inside of windows, as they are often easier to place—especially for windows at the top of tall buildings. But researchers found that decals placed on the outside of windows were much more effective at reducing bird strikes than those placed on the inside of windows.

4. Human shields can be lethal for midsized predators

When large predators like wolves (Canis lupus) or pumas (Puma concolor) are around, some bobcats (Lynx rufus) and coyotes (Canis latrans) choose to move closer to humans, thinking that the ‘human shield’ is the safer of two bad options. But research reveals that humans may actually cause more danger to these mid-sized predators. Many bobcats and coyotes that moved closer to humans while larger animal predators were around were killed by hunters and trappers.

3. Tough regulations work best to stem wild pig invasion 

Since their introduction into the United States with European settlers, wild pigs have expanded quickly across the continent. Every state enforces different regulations to manage these pigs. Researchers examined the state of the invasive pig problem in many of these states and compared them with the effectiveness of each one’s regulations.

2. As the climate changes, wild turkeys aren’t keeping up

We’re more than a month past Thanksgiving, but the weather hasn’t cooled for wild turkeys (Meleagris gallopavo). Researchers have found that warmer, wetter weather early in spring may be throwing out of whack what used to be the birds’ nesting season. The invertebrate food they rely on may hatch earlier, meaning there won’t be enough for young poults if they hatch later on.

1. Rising oryx numbers may distress New Mexico ecosystem

You’d be mistaken if thinking that the best place to see South African oryx (Oryx gazella) this side of the Atlantic Ocean would be a zoo. The New Mexico Game and Fish Department first introduced these ungulates, also known as gemsbok, to the state as game animals, and they have taken off in some parts of the ecosystem there. The trouble is, these newcomers may outcompete native species like pronghorn {Antilocapra americana) and mule deer (Odocoileus hemionus) in New Mexico.