Golf course gators munch on more spider, insects

October 30, 2023 by Joshua Rapp Learn

The pace of life on golf courses seems to suit alligators perfectly fine in some ways—especially when there are plenty of water hazards. But the food on the greens has changed the diets of some of the reptiles, from seafood to insects.

“When we, human beings, modify the landscape in a major way by constructing a golf course, we are influencing the diet of these large predators,” said Adam Rosenblatt, an assistant professor of biology at the University of North Florida.

Rosenblatt studies the pressures and changes of urban development on large predators. Alligators (Alligator mississippiensis) are common on golf courses in the southeastern U.S., especially those that have a number of ponds, lakes and other water traps. But, “nobody has ever studied alligators on golf courses,” Rosenblatt said. He wondered how the greens might be affecting their diet.

Rosenblatt led a study on this topic recently in Ecology and Evolution that brought him and his colleagues to Jekyll Island in southeastern Georgia—a resort island with four golf courses and more than 100 resident alligators living on them. In 2019, the team captured 25 juvenile gators, and in 2020, they caught 18.

To conduct their research, they strapped each gator they captured to a wooden board. They then pumped their stomachs by inserting PVC piping into their mouths and slowly pouring water into the pipes. Finally, they used a kind of Heimlich maneuver movement to bring out the stomach contents.

“It’s a very exciting process,” Rosenblatt said. Once they had a bucket full of gator vomit, they took it to the lab to analyze it more closely.

Rosenblatt’s colleague James Nifong at the University of Florida had previously conducted a study using the same technique on alligators he captured on nearby Sapelo Island, an area with few people and no golf courses, at the same time of year in 2009 and in 2010. Though there was a decade between the two studies, Rosenblatt said that no major landscape disturbances or developments had resulted in significant changes at either Jekyll or Sapelo. The team used the data from juveniles captured in this earlier study to compare to the golf course juveniles.

The remains of a hamburger and french fries found in an alligator on a golf course. Credit: Joseph Colbert

Golf course diet

The researchers found that the gators on Jekyll had eaten a few more strange food items than those on Sapelo. Rosenblatt found french fries and bits of hamburger—cheese, bun and pickles included—in one gator. “[Someone] either forgot their leftovers on the ground or decided to throw them in the nearby water body,” Rosenblatt said. “[The gator] had probably just eaten it in the past hour or so before we pumped its stomach.”

Another had eaten a whole bunch of canned corn—Rosenblatt speculated that it came from someone who poured it on the ground trying to attract other wildlife like deer or birds.

“I was disappointed,” Rosenblatt joked. “I thought we were going to find some golf balls.”

The earlier surveys on Sapelo didn’t turn up any of these kinds of strange food items. In fact, the gators there mostly ate crustaceans. This diet usually comes from the way they use their territory—the Sapelo gators often move between freshwater ponds on the island and the saltwater on the coast, where they find abundant crabs.

Meanwhile, the golf course gators’ diets included a much heavier portion of arthropods—mostly beetles and giant water bugs, with some other insects and spiders.

Rosenblatt isn’t completely sure why, but he said the golf courses might attract these kinds of insects, providing a steady source of food for gators. With the “abundant prey and these freshwater ponds just sitting there,” Rosenblatt said, it makes sense why the gators choose these areas. 

The golf courses may change the way water flows on Jekyll Island, which could reduce the number of crabs. At the same time, golf courses are often treated with pesticides, which could be reducing crab numbers on the greens. They could also be getting into beetles and water bugs the gators eat in large numbers. These chemicals may bioaccumulate in the bodies of these alpha predators, but further research would be needed to confirm this.

The researchers aren’t sure whether this change in diet is good or bad. Most of the gators that live on golf courses don’t move around as much as the ones on Sapelo, so in some sense, they might be getting the food they need. And it’s not as if juvenile gators elsewhere don’t eat arthropods, albeit in different quantities. “I don’t think they are necessarily worse off,” Rosenblatt said of the golf course gators.

Efforts successfully control wild pig invasion

October 30, 2023 by The Wildlife Society

The invasion of wild pigs in the southeastern U.S. can seem like an insurmountable problem, but researchers have found that some recent conservation efforts have been effective at controlling their populations.

Control efforts around a study site in South Carolina reduced wild pig (Sus scrofa) abundance by 70% in two years, and the environmental damage from their destructive rooting behavior nearly disappeared. The team published their findings in Pest Management Science.

“With sustained management, the population should continue to shrink over the next several years,” said lead author Jim Beasley, a professor and researcher at the University of Georgia’s Savannah River Ecology Laboratory and Warnell School of Forestry and Natural Resources. “However, what is unknown is how quickly the population will recover if management efforts cease.”

Annual damages from wild pigs in the U.S. can top $1 billion.

Read more from the University of Georgia.

Warming Arctic may pose new risks to endangered right whales

October 27, 2023 by The Wildlife Society

As rising temperatures shrink polar icecaps, sea creatures are migrating northward, and commercial fishing boats are following them. That could lead to more ship collisions and gear entanglements for the critically endangered eastern population of North Pacific right whales (Eubalaena japonica) in the narrow Bering Strait.

“Prey are responding to the changing climate, and species at the top of the food chain are too,” said Dana Wright lead author on a recent study in Ecological Applications.

The Pacific hosts two populations of right whales. The eastern group, found in the waters off Alaska and the Canadian Pacific, is thought to number just 30 animals. Sightings are rare, but researchers believe the animals are following zooplankton northward.

Read more from Duke Today.

Q&A: Human studies on PFAS can inform wildlife conservation

October 27, 2023 by Dana Kobilinsky

Scientists often look to animals to learn more about human health, but studying humans may also help us understand wildlife health, too. In a recent paper, researchers discussed using research on humans to better understand the presence of PFAS—sometimes called “forever chemicals”—in wildlife.

The Wildlife Society caught up with Tasha Stoiber, a senior scientist with the nonprofit Environmental Working Group and an author on the discussion paper published in Science of the Total Environment, to learn more about using humans as a sentinel species for wildlife. Responses are edited for style and brevity. 

Headshot of Tasha Stoiber.

How did your study of PFAS in humans shift to studying it in wildlife?

Our organization has been looking at PFAS contamination in drinking water and the related human health effects for over two decades. From there, we really wanted to understand and see, how is this affecting wildlife? 

We found hundreds and hundreds of studies showing all different types of wildlife—from marine mammals to insects—are contaminated across the globe. It’s really staggering. So we started thinking about how this is affecting animal health and how that could affect animal populations.

There’s not much in the literature about the effects of PFAS on wildlife because it is really difficult to study wild animals. But we have this body of research that clearly show associations with PFAS exposure to numerous health effects in humans.

We highlight in the paper a number of parallels of what we know about how PFAS affects human health with wildlife. There are a number of papers that observed in wildlife immune system effects, endocrine system effects, and it’s striking. We can use what we know about human health to fill in some of the data gaps this way for wildlife. 

How can your map help managers or researchers?

We know that nearly every human has PFAS in their blood. Similarly, the maps show how virtually every species is susceptible to PFAS exposure. It’s a global map. You can turn on and off different layers mapped out by different species—small mammals, large mammals, aquatic mammals, birds, reptiles and other filters. It really highlights just how widespread exposure is and how much of a global problem it is.

How can humans be sentinels for environmental health? 

In the paper we discuss the One Health concept, where the health of animals and the health of humans are connected. We need to understand how chemical exposures are affecting all of us together. All the actions that will help humans will also help animals, and that’s what’s really needed for sustainability in the long term. 

The classic view is that animals are sentinels for environmental and human health. That’s the human-centered view of this, and there’s so many different examples of this. Methyl mercury exposure was first noted in cats, and then the issue was discovered in humans. And then there’s the cliché of the canary in the coal mine that is used over and over. 

But in this case, for PFAS exposure, we have more data about human health than we do wildlife. Given the situation currently, where we’re experiencing unprecedented rates of biodiversity decline, loss of habitat and climate change pressures, we’re at a point where we need to look at all of these different factors and include that additional stressor of chemical exposures.

We’ll never be able to study wild animals as much as we need or want—especially endangered species. We’ll never have the data that we need to really understand how they’re being affected. So we’re just starting that conversation of how we can use what we know about humans and extrapolate that to figure out what we can do to protect wildlife. 

What can we do to limit PFAS exposure in both humans and wildlife?

If we’re going to place a burden on anyone, it should be the polluters. They should be the ones that should be facing the penalties and be facing the cost to clean up their environmental pollution in the first place. Image Caption: Studies have shown PFAS in American alligators (Alligator mississippiensis) can affect their autoimmune systems. Researchers say further research on the chemicals in humans can help us understand how they affect wildlife.

Rick Warhurst earns Distinguished Service Award

October 26, 2023 by The Wildlife Society

The Central Mountains & Plains Section has selected longtime TWS member Rick Warhust to receive The Wildlife Society’s 2023 Distinguished Service Award.

The award recognizes individuals who have worked throughout their careers to further the mission of The Wildlife Society.

The award will be presented during TWS’ Annual Conference in Louisville, Kentucky, next month.

“Rick is an outstanding wildlife professional that has contributed to waterfowl and wetland conservation throughout North America,” wrote Embere Hall, CMPS Awards committee chair, in a nomination letter. “Additionally, he has volunteered for numerous roles and leadership responsibilities within TWS including with state chapters and the Central Mountains & Plains Section.”

Warhurst has devoted his career to waterfowl and wetland conservation, serving in roles with the Ohio Division of Wildlife, the Kansas Department of Wildlife and Marks, Ducks Unlimited and the North Dakota Natural Resources Trust. He has also served as the Central Flyway

Representative on North American Wetlands and Chair of the Habitat Subcommittee of the

Central Flyway Council and Technical Committee for most of his professional career.

He has also volunteered much of his time advancing the mission of TWS. A TWS member since 1969, he has been a life member of the North Dakota Chapter, a member of the Ohio Chapter and a member of the Kansas State University Student Chapter. He has served as an executive board council member and president for the North Dakota Chapter and as secretary for the Ohio Chapter.

He has also served as the liaison between CMPS and North Dakota Chapter and has volunteered to serve as an executive board member for the section. He also mentors new professionals and has supported student chapters throughout North Dakota.

“It is impossible to overstate Rick’s contribution to waterfowl and wetland conservation,” Hall wrote. “His professionalism and steadfast devotion to conservation and management of North America’s Prairie Potholes is unmatched. Rick’s fingerprint is on the majority of most of our crucial conservation efforts in the Central Flyway over the last half century. Future generations will be able to enjoy watching large flights of migrating ducks largely due to Rick’s tireless efforts to help conserve wetlands during his career as a wildlife professional.”

Development pushes one Blanding’s turtle population to the brink

October 26, 2023 by Dana Kobilinsky

A residential project will result in the complete loss of a Blanding’s turtle population in Ottawa, researchers found.

Within the next decade, biologists believe the population will reach what they call “quasi-extinction,” with fewer than four individuals left.

“For that population, it’s too late,” said Gabriel Blouin-Demers, a biology professor at the University of Ottawa.

Blouin-Demers is an author of a study published in Animal Conservation using telemetry and mark-recapture to study the freshwater turtles before and after the residential development near a major Ontario road called Terry Fox Drive.

The construction project had been approved in the 1980s, although construction had been put on the shelf for years. By 2010, when the project was meant to begin, concerned citizens brought forth concerns about Blanding’s turtles (Emydoidea blandingii) living there. Blanding’s turtles, found in the Great Lakes region in southern Ontario northwest to Sault Ste. Marie and east to southwestern Québec, are listed as endangered under the Canadian Species at Risk Act.

Provincial laws required developers to mitigate impacts to wildlife, but those measures didn’t prevent the destruction of critical habitat, Blouin-Demers said. While developers placed fencing along Terry Fox Drive to divert turtles toward passages like culverts, he said, the fences abruptly ended at entrances, rather than forming a U shape to redirect them away from the road. As a result, the turtles followed the fencing to busy Terry Fox Drive, where researchers found several dead animals each year.

In addition, construction crews bulldozed the landscape without leaving enough habitat for the species. A pond for the turtles was created dangerously close to the main road, researchers found, and a proposed artificial nesting site beside it was unusable.

 “There was no maintenance done, so now it’s totally overgrown,” Blouin-Demers said. “It’s not open anymore, and when you dig, the water table is so shallow that within 10 centimeters, you’re in water. Turtles don’t nest in water.”

After comparing telemetry data on the turtles from 2010 to 2013—before the project — and from 2017 to 2020—after construction—Blouin-Demers and his colleagues found connectivity was reduced by more than 50% for the species. In just a decade, mark-recapture data indicated the population fell from 80 individuals to just 25.  Because females are more at risk of road mortality, the sex ratio of the population skewed toward males, resulting in fewer young being recruited.

“It was not a muddy story,” Blouin-Demers said. “It was pretty clear.”

Extending their population model into the future, the team found that within the next decade, the population will have fewer than four individuals and eventually will dwindle to zero.

While Blanding’s turtles remain in other areas of Ottawa, Blouin-Demers said, the tale of this population illustrates what can happen when not enough is done to prevent extirpation.

“The hope is that by showing what happened with insufficient mitigation measures and insufficient monitoring of the success of those measures, that we don’t make the same mistakes down the road,” he said.

Are Florida’s invasive caimans on the way out?

October 25, 2023 by The Wildlife Society

Florida has grappled with a host of invasive species that thrive in the warm, moist climate. But one species may soon be on the way out. A team of biologists known as the “Croc Docs” have been working to eliminate the nonnative spectacled caiman (Caiman crocodilus) from the state, and a recent study published in Management of Biological Invasions suggest its populations are declining.

The reptiles look like alligators (Alligator mississippiensis), but they are native to Central and South America. In the 1970s, the leather industry brought hundreds of thousands of them to Florida, the New York Times reports, but they often were sold as pets, and weary pet owners inevitably released them into the wild.

The Croc Docs say their captures have been declining—either because the caimans are getting savvier, or very possibly, because their numbers falling. 

“I do think this is a species we can successfully eradicate,” Joshua Friers, cultural and natural resources manager for Homestead Air Reserve Base, where the caimans have been particularly problematic, told the Times.

Read more from the New York Times.

USFWS rule would expand area for ferret reintroduction

October 25, 2023 by Tom Klein, AWB®

The USFWS has mapped out a major habitat expansion for black-footed ferret reintroduction in a final rule. 

This rule, which expands designated black-footed ferret habitat by 184%, will take effect Nov. Nov. 6, 2023.

The rule provides “ a framework for establishing and managing reintroduced populations of ferrets in this area that will allow for greater management flexibility and increased landowner cooperation,” wrote the USFWS wrote in its final rule notice.

Deemed the “Southwest Experimental Population Area,” or SWEPA, spanning parts of Arizona, New Mexico, and Utah,”  the area encompasses approximately 41 million acres.

That area includes the previously established Aubrey Valley Experimental Population Area, where  black-footed ferret (Mustela nigripes) reintroduction has been managed since 1996 as part of a nonessential experimental population under section 10(j) of the Endangered Species Act.

Section 10(j) of the ESA allows the USFWS to designate a population of a listed species like the black-footed ferret as experimental to release into suitable natural habitat outside of its current range.

The Southwest Nonessential Experimental Population Area as mapped out by the USFWS. Credit: USFWS


Experimental populations may be categorized as essential or nonessential. Nonessential experimental populations have loosened restrictions on take–to harass, harm, pursue, hunt, shoot, wound, kill, trap, capture or collect an animal–compared to other federally threatened and endangered species. When designated as a nonessential experimental population, incidental harm to black-footed ferrets is legal when resulting from traditional land uses and management, encouraging cooperation from private landowners.

The Wildlife Society encourages greater partnerships among state fish and wildlife agencies, Native American Tribes, local governments, private landowners  and NGOs in carrying out complementary conservation efforts on private and other nonfederal lands to recover listed species and prevent the need to list additional species.

Black-footed ferrets were listed as endangered in 1967 under legislation passed before the ESA. They were grandfathered into the ESA in the 1970s, and approximately 350 exist in the wild today. The current population is the result of captive breeding efforts, originating from just seven breeding ferrets that were captured in 1985. The black-footed ferrets in the wild now are all descended from these seven ferrets, leaving the overall population with a severe lack of genetic diversity.

Black-footed ferrets primarily feed on prairie dogs and live within their colonies, making them heavily dependent on the health of prairie dog populations. Sylvatic plague, transmitted by fleas, is currently the greatest threat to prairie dogs and ferrets as it has an approximate 90% mortality rate and can completely collapse colonies leading to local extinctions. Pesticides to eliminate fleas and vaccination efforts of prairie dogs and ferrets have helped.

The Wildlife Society recently expressed support for increased appropriations for critical renovations to the USGS National Wildlife Health Center, which has been instrumental in the research and development of these vaccines.

In the cities, male sparrows do it all

October 24, 2023 by Dana Kobilinsky

Male song sparrows take their father position very seriously when they’re living in the city—they defend their nests and take care of their chicks at the same time.

That was surprising to researchers, who thought they might have to spend more time aggressively maintaining their territories and would have to trade off parental care with females.

“Urban sparrows are more bold and aggressive than their rural counterparts,” said Samuel Lane, a National Science Foundation postdoctoral research fellow in biology at North Dakota State University. “But we didn’t really understand the consequences of this increased aggression.”

Lane led a study in Kendra Sewall’s lab at Virginia Tech that was published in Frontiers in Ecology and Evolution testing out how aggressive and paternal male urban and rural song sparrows (Melospiza melodia) were and comparing how successful they were at raising young.

Male song sparrows took care of chicks and defended their nests in urban areas. Credit: Taylor E. Fossett

To conduct the research, Lane and his team first had to catch some birds. They caught them in mist nets and fitted them with PIT tags—coils of magnetic wire encoded with a unique ID. Whenever the tag got close to an antenna at the nest, it would record the unique ID.

At the beginning of the breeding season, Lane and his colleagues played sounds of another male in the center of song sparrow territories in both urban and rural areas in southwestern Virginia. They also placed 3D-printed song sparrow mounts to represent another bird. They recorded how close each bird got to the mount and how many wing waves and vocal displays the males performed over 6 minutes, as a way to determine how aggressively they were defending their territories. The researchers also recorded parental care and nest success.

They found that for urban birds, there wasn’t a tradeoff between parenting and aggression. “Essentially, if you’re going to look for the most aggressive and the most paternal dads, they were all in urban habitats, which was super surprising,” Lane said.

Lane said this is likely because the urban males are freed from some of the constraints that exist in rural habitats, especially predation.

Nesting success was also higher in urban locations. In some years, 80% of the nests were predated in rural areas, but predators were probably fewer in urban areas, and urban predators like raccoons (Procyon lotor) and opossums (Didelphis marsupialis) are more likely to eat trash than birds.

The findings suggest that song sparrows do better in urban areas. “Song sparrows are very hardy, and they seem to readily acclimate to these urban environments,” he said. They may also benefit from consistent food and water in urban habitats from things like agriculture and from other resources like shrubs.

Lane hopes this research adds to the body of knowledge of how different species perform in urban environments. “In general, you see decreases in biodiversity as you move into urban habitats,” he said. “But there’s some species that do really well in urban habitats. What we hope is that by continuing to do research like this in urban ecology, you can better understand what these animals are benefiting from in urban environments and hopefully design these urban environments to better support wildlife.”

After strong recovery, Antarctic fur seals face new threat

October 24, 2023 by The Wildlife Society

Antarctic fur seals have recovered from the brink of extinction, but they now face dangerous declines due to lack of food.

In a study published in Global Change Biology, researchers found that the fur seal peaked in 2009 at about 3.5 million. A detailed study of seals occupying one South Georgia island found numbers are plummeting as the seals struggle to find krill.

“We found both good and bad news about the fur seals,” said Jaume Forcada, a British Antarctic Survey scientist who led the new study. “The population has recovered very impressively throughout the twentieth century when seal hunting was banned. But twenty-first century changes to the abundance of krill in the Southern Ocean are now threatening these iconic animals all over again.”

Researchers found that rapidly rising sea temperatures in the region correlate with the seal population decline—pointing to a loss of krill as the most likely cause.

Read more from the British Antarctic Survey.