Humans have impacted lion genetics over the years

December 7, 2020 by Dana Kobilinsky

Over the past century, a growing human population has caused movement barriers for lion populations, reducing their genetic diversity.

“The African landscape has changed drastically over the past century with human population increases, management of wildlife and landscapes, etc.,” said Caitlin Curry, a doctoral candidate at Texas A&M University College of Veterinary Medicine & Biomedical Sciences. “We wanted to see the genetic impacts these changes have on an apex predator across their range.”

Curry led a study published in Molecular Biology and Evolution looking at modern and historical data on lions (Panthera leo) from India to southern Africa. The modern data was collected from recent studies, including one that Curry was involved in.

The historical data came from specimens from 143 lions in museums across the world collected prior to 1949, but they came with a high potential for DNA degradation, Curry said. As a result, they had to develop protocols to extract and sequence low quality and sometimes low quantity DNA from these samples. “Aside from just the age of the specimen, everything from the methods for preserving the specimen to how it’s been stored can greatly affect the level of degradation,” she said.

After comparing the historical and modern data, the team found that humanity has made an observable impact on the genetic diversity of lions. The team looked at mitochondrial DNA, inherited by the mother, as well as nuclear DNA, which is inherited by both parents. They found that gene flow from males was interrupted by habitat fragmentation. This caused a decrease in genetic diversity, as subpopulations became more differentiated between one another. “The spatiotemporal genetic patterns observed in lions shows how quickly habitat fragmentation can alter genetic structure and diversity in only a handful of generations,” Curry said.

While human populations in lion country have been greatly increasing since the 1800s, the team was still surprised by the findings. “Surprised and disappointed, because it’s not what I wanted to see,” said James Derr, a professor of veterinary pathobiology and genetics at Texas A&M and an author on the study. “I really wanted to be able to tell everyone that the management we’ve been doing for the last 100 years is perfect and to keep doing what we’ve been doing and everything will be fine. But that’s not the take-home lesson. Unfortunately, that’s not the story we can tell.”

But the researchers say all hope shouldn’t be lost for the lion populations. “This should not be a disheartening story but rather one of hope,” Curry said. “Yes, we see a decrease in genetic diversity across lion populations over the past century. But, currently, compared with other mammalian species, lion genetic diversity is still considered high across all lion populations.”

Curry suggests continuing responsible management focused on giving prides enough space to breed and allowing males to move more freely between isolated subpopulations in order to increase genetic diversity.

“The positive take-home message is now that we’ve documented this and we understand it, policies can be tailored to manage these populations differently,” Derr said. “We know now that you can’t treat all lions the same. Now we have the responsibility to manage these animals, and many other managed wildlife species, in ways that better reflects their current biology.”

The next step is sharing research like this managers, Curry said, “so they can make informed decisions and use scientifically based conservation strategies to protect the lion and its ecosystem.”

TWS2020: Parasites may reduce endangered squirrels’ survival

December 7, 2020 by Joshua Rapp Learn

Invasive Abert’s squirrels may be passing harmful parasites to endangered native Mount Graham’s squirrels in Arizona.

Ongoing research on these squirrels and the creatures that live off of them has implications for the management and conservation of the endangered species.

“We’re trying to identify and see what parasites both of these squirrels have,” said TWS member Deandra Jones, a master’s student in wildlife management and conservation at the University of Arizona and member of the Navajo Nation.

Mount Graham’s red squirrels (Tamiasciurus hudsonicus grahamensis) are an endangered subspecies of the red squirrel (Tamiasciurus hudsonicus), which is endemic to the Pinaleño Mountains southeast of Tucson, Ariz. The squirrels suffered huge losses in 2017, when the Frye Fire burned much of the forest ecosystem they relied on in the mountains. Their numbers dropped from an estimated 242 individuals in 2016 to only 33 squirrels right after the fire, according to the Arizona Game and Fish Department. Those numbers have since rebounded to at least 109 individuals, according to a recent survey by the state agency, the Phoenix Zoo and the University of Arizona.

Researcher Deandra Jones dissects an Abert’s squirrel. Credit: Deandra Jones

But the native squirrels face another problem. In the 1940s, the Arizona Game and Fish Department introduced Abert’s squirrels (Sciurus aberti), native originally to the southern Rocky Mountains, to the Pinaleño Mountains for hunting as they thought the native Mount Graham’s squirrels had been extirpated from the region. These non-native squirrels now outcompete the native Mount Graham’s in the area.

In Jones’ ongoing research, presented on a poster at The Wildlife Society’s virtual 2020 Annual Conference, she is seeking to discover whether the newcomers are also passing on parasites to the vulnerable population of Mount Graham’s squirrels and whether these may negatively impact the health and survival of the population.

Jones and her colleagues have been conducting necropsies on both species of squirrels to determine what types of critters live in their gastrointestinal tracts. So far, they’ve analyzed about 100 Abert’s squirrels, brought to them by the state wildlife agency as part of an ongoing eradication program in the area, and 23 native Mount Graham’s squirrels that died either as a result of roadkill, predators or other reasons.

So far, Jones said that the Abert’s squirrels have much higher proportions of parasites than the native squirrels. More than 60% of the introduced species they studied carried endoparasites, while only 38% of the Mount Graham’s red squirrels had the gut parasites.

A female nematode found in squirrels, with eggs visible inside. Credit: Deandra Jones

The researchers haven’t yet determined which species of worms are infecting the squirrels, and they are planning on conducting future studies to look at ectoparasites, or those that feed on the outside of the animals’ bodies like ticks or fleas.

Other factors like insect outbreaks also affect Mount Graham’s squirrels, but learning more about the parasites that Abert’s squirrels may pass along to their endangered cousins is important for building effective conservation plans.

Meanwhile, another poster presented by Hejie Xu from the University of Arizona at the TWS conference this year shows how she and colleagues intend on researching the ways that traffic and vehicles might affect Mount Graham’s red squirrels.

This research was presented at TWS’ 2020 Virtual Conference. Conference attendees can continue to visit the virtual conference and review Jones’ paper for six months following the live event. Click here to learn about how to take part in upcoming conferences.

Invasive wasps can take down airplanes

December 7, 2020 by The Wildlife Society

Dime-sized wasps may be able to knock airplanes out of the air due to their proclivity for building nests in plane parts critical for navigation. Keyhole wasps (Pachodynerus nasidens) are native to Central America and the Caribbean, so-called for their tendency to lay their nests in large, old-school keyholes. But in 2013, an Airbus was forced to abruptly land after takeoff in Brisbane, Australia when the airspeed readings of the plane came back dysfunctional. Investigations revealed that invasive keyhole wasps had laid their nests in the tube used to measure airspeeds on the plane. Since then, 26 wasp-related issues were reported at the Brisbane Airport. In laboratory tests conducted as a follow up, these wasps were responsible for 39 instances of fully blocked airspeed measurement tools for airplanes. The researchers cautioned that the wasps could present a growing threat to tropical and subtropical regions as they continue to spread across the world. “The consequences of not managing this clever but dangerous pest could be substantial,” they said in a press release.

Read more at Gizmodo.

Watch: Vancouver Island marmots are rebounding

December 4, 2020 by The Wildlife Society

Vancouver Island marmots are Canada’s most endangered mammal, but they’re populations have been rebounding. From a low of 30 wild marmots (Marmota vancouverensis) occupying just a few locations in 2003, they have increased to about 200 spread out across 20 Vancouver Island mountains, thanks to a successful captive breeding and release program. More than 100 marmot pups were born in the wild over the last two years.

“I think there’s reason for real optimism, that we have some science and some modeling that is demonstrating that we have an approach that can bring this species back,” Adam Taylor, executive director of the Vancouver Island Marmot Recovery Foundation.

Biologists have found success releasing marmots first to the Mount Washington ski area, where they can acclimate to a natural environment. They hope the success with the marmots can build support for recovering other endangered species.

“We need success stories in the conservation world. This is not an easy time to work with wildlife,” Taylor told Canada’s National Observer. “We need to be able to demonstrate that it’s possible to bring these species back because that’s the task that we’re going to be engaged in more and more often. And if we don’t have success stories, then it’s going to be really hard for us to justify why we want to save any one of these species.”

Read more from the National Observer here, and watch below for a glimpse at a pair of Vancouver Island marmot yearlings caught on camera.

https://twitter.com/MarmotRecovery/status/1265122416717512705

Kentucky aquatic snakes have high fungal disease prevalence

December 4, 2020 by Joshua Rapp Learn

Aquatic snake species in Kentucky have high incidences fungal disease, which may affect their behavior without impacting their short-term survival.

“We did see that snakes — especially the queen snakes — were less likely to move. [The diseased snakes] tended to stay in the same spot,” said Steven Price, an associate professor of stream ecology at the University of Kentucky and one of the co-authors of a study published recently in Ecological Applications.

He and his colleagues had been capturing aquatic snakes around Lexington, Ky. for some time, implanting them with tracking devices so they could conduct mark-recapture studies. In 2014, they’d begun to notice lesions on many of the snakes. That and other signs pointed to snake fungal disease — an infection caused by a pathogen that has been found in more than two dozen snake species in the United States including Puerto Rico as well as Ontario, Canada. Researchers don’t fully understand how it affects serpents, but it can be deadly, and some studies show that it can drain the reptiles’ energy and dry them out.

First author Jennifer McKenzie processes a snake. Credit: Jake Hutton

In 2016-2017, Jennifer McKenzie, who led the study as part of her master’s work at the university, and her co-authors implanted PIT tags, or electronic microchips used for tracking, in 526 snakes from two species: queen snakes (Regina septemvittata), a species that feeds on freshly molted crayfish, and common watersnakes (Nerodia sipedon), a reptile found widely across eastern North America.

They determined the prevalence of the disease using photographs of lesions and genetic tests that identified Ophidiomyces ophidiicola, the fungus that causes the snake fungal disease called Ophidiomycosis. The large-scale study revealed that 40% of queen snakes and 20% of watersnakes had the disease.

“We have a high number of snakes that have the disease in our populations,” Price said.

A queen snake with clinical signs of the fungal disease on its head. Credit: Andrea Drayer

To Price and his colleagues, the numbers weren’t surprising. They had already witnessed these high proportions of infected snakes in previous work. But he said that other researchers have been shocked about the high number.

But Price and his colleagues’ study didn’t seem to show that the disease was particularly deadly during their study year — diseased snakes didn’t die any more than non-diseased snakes. But he cautions that this could be due to the short length of the study, or to favorable environmental conditions during the study year. Some researchers believe that environmental conditions, like a wetter year or cooler air temperatures, can make the disease deadlier.

While some researchers have previously noticed higher numbers of deaths from the disease as the snakes emerge from their winter hibernacula, Price noted they didn’t observe a higher death rate in the spring in their study.

Student researchers search for snakes in streams in central Kentucky. Credit: Jake Hutton

But they did notice some changes in snake behavior. Snakes that were infected with the disease seemed to spend more time basking and moved less. This could be a way for the snakes to conserve energy or even induce fever. Reptiles and amphibians can’t induce the fever conditions that help them fight disease automatically like warm-blooded mammals can, so they try to develop these conditions by using outside heat from sunlight or other environmental conditions.

“They’re essentially trying to fight this effect by heating up more, by inducing a fever,” Price said.

But Price noted another bias may occur when normally cryptic snakes bask out in the open more and are easier for researchers to spot than uninfected serpents. Researchers should be aware of these behavioral changes as they could lead to over estimations in disease prevalence in snake populations.

The mark-recapture work is ongoing, though, and Price hopes to be able to better answer questions of long-term survival as more data comes in from their study sites.

Wolves alter Minnesota wetlands

December 4, 2020 by Dana Kobilinsky

Wolves in Minnesota’s Voyageurs National Park are changing the wetlands ecosystem there, researchers found, due to their appetite for beavers.

“Wolves eat a lot of beavers, especially in Voyageurs, where there are a ton of beavers and lot of wolves,” said Thomas Gable, lead researcher on the Voyageurs Wolf Project, a collaboration between the University of Minnesota and Voyageurs National Park, and the lead author of the study recently published in Science Advances. “Beavers have often been ignored by wolf biologists, in part because beavers are not as important on a socioeconomic level as species like deer.”

But beavers are an ecosystem engineer, creating maintaining and altering wetlands, which are important for many wildlife species.

Tom Gable collects a beaver jaw at a site of wolf predation. Credit: Tom Gable

Just three weeks into his fieldwork as a master’s student in 2015, Gable saw how dispersing wolves (Canis lupus) were killing juvenile beavers (Castor canadensis) in the park. The region’s wolves had come off the endangered species list just three years earlier, and Gable wondered how they were impacting the park’s beaver populations. Previously, biologists struggled to find evidence of wolf predation on small prey during the summer—they often don’t leave many traces behind for researchers to find.

Gable and his colleagues decided they were up for the challenge. After collaring wolves in the park, they watched for the animals to spend at least 20 minutes in a spot, then moved in searching for signs of a kill.

The search “oftentimes involved getting down on your hands and knees, literally, looking through vegetation for tufts of fur or intestinal content,” Gable said. Since wolves in the park typically only eat beavers and deer fawns during summer, he said, identifying the fur was an easy way to tell which animal was preyed on. The next step was looking more closely at where and how these wolf-beaver interactions occurred.

Culminating five years of intensive wolf-beaver interactions, the recent study confirmed initial anecdotal evidence that wolves stopped beavers from creating their ponds, which raised questions about what that may mean for wetland creation in the larger ecosystem.

A beaver chews on a stick in Voyageurs National Park. Credit: Tom Gable

“By 2019, we were able to look at this in a quantitative sense, as opposed to several one-off observations, which allowed us to put this all together,” Gable said.

The team found that wolves often killed juvenile beavers that were setting out to create a dam in a new stream or repair a dam in an old, abandoned pond that had drained. Beavers are particularly vulnerable to predation in these low waters, he said, and wolves have an easy meal.

Once the beavers are gone, the ponds vanish with them. “The dam deteriorates and the pond drains,” Gable said. “Not only that, but our data shows that no other beaver ends up settling in those spots.” As a result, researchers found, wolves were altering the landscape. “It shows wolves, indeed, are connected to wetland creation,” Gable said.

The researchers determined that wolves prevented about 88 ponds per year from forming in the Greater Voyageurs Ecosystem. “That’s a drop in the bucket” in the larger ecosystem,” Gable said. “But on a localized level, it totally changes the environment.”

This mechanism is likely also occurring in other areas where wolves prey on beavers, Gable said. While not affecting beaver population size, wolves are impacting their distribution, he said, reshaping the wetlands they occupy and creating more diverse landscapes.

Beaver dams and ponds seen from above. Credit: Tom Gable

The team also found other surprises. Previous work found wolves tend to outrun and outlast their prey, but their research showed wolves ambushed beavers, often sitting and waiting for hours at a time before springing.

“Wolves do, in fact, ambush their prey, but can switch back and forth between ambush strategies to catch beavers and then cursorial strategies to catch prey like deer,” Gable said. “It’s quite fascinating.”

“I think the value in a lot of our work is understanding the functional role of predators in ecosystems, whether or not that information is used as a justification for predator reintroduction or conservation,” he said. “That’s up to managers. But it’s really important for managers to have a sound understanding of how the presence of large predators impacts the ecosystem.”

U.S. Forest Service releases final NEPA rule

December 3, 2020 by Laura Bies

A final rule published by the U.S. Forest Service has now changed its National Environmental Policy Act regulations to include new exemptions of projects from environmental review.

In addition, the changes include a new process for determining whether a previously completed Forest Service NEPA analysis can satisfy NEPA requirements for subsequent action.

The crux of the changes is new or expanded “categorical exclusions,” which are categories of actions that do not require environmental analysis, since they have historically been found not to result in significant environmental impacts. The new categorical exclusions will apply to restoration projects such as removing disease-killed trees or restoring streams, infrastructure activities such as removing old roads or trails, and special uses and permitting activities such as authorizing development or outfitters and guides.

“The new categorical exclusions will ultimately improve our ability to maintain and repair the infrastructure people depend on to use and enjoy their national forests — such as roads, trails, campgrounds and other facilities,” said U.S. Secretary of Agriculture Sonny Perdue in a press release from the agency.

Some of the categorical exclusions were adjusted from those proposed last year, based partly on public input received during a comment period. For example, the maximum categorical exclusion for restoration projects was reduced from 7,300 acres to 2,800 acres. The agency also changed the types of action that could qualify for the restoration and resilience exclusion, removing the salvage harvesting of dead or dying trees.

The final rule was originally scheduled to be released over the summer, but that was delayed in order to allow the USFS to align their changes with guidance issued by the Council on Environmental Quality regarding NEPA implementation across all federal agencies, which was released in July. The agency now plans to reconsider several proposals regarding public engagement requirements, types of projects requiring an environmental impact statement and the use of other agencies’ categorical exclusions, and release additional changes by September 2021.

The final rule was published in the Federal Register on Nov. 19 and took effect immediately. More information about the process of developing the rule can be found here.

Canadian government unveils new bill to tackle climate change

December 3, 2020 by Laura Bies

A new bill introduced by the Canadian government commits the country to reaching net-zero greenhouse gas emissions by 2050.

The bill sets mandatory national five-year targets to cut emissions, starting in 2030, although it does not specify how those emissions reductions should be achieved. The bill also does not include specific mechanisms for reducing emission or include enforcement mechanisms or include penalties for failing to meet targets.

According to Prime Minister Justin Trudeau, the bill is an accountability framework that will “ensure we reach this net-zero goal in a way that gives Canadians confidence.” The bill requires that the prime minister bring forward a plan to Parliament outlining how the government will meet the legislation’s emissions goals.

The legislation will also establish a 15-member advisory board, composed of climate experts, scientists and others. That board would provide advice to the environment minister on setting emission reduction targets. The bill also requires the finance minister to prepare an annual report each year detailing “key measures that the federal public administration has taken to manage its financial risks and opportunities related to climate change.”

Some climate activists criticized the bill for not being ambitious enough, while some conservative lawmakers voiced concerned about the cost of the emissions reductions. Canada’s current target, established by the former administration in May 2015, is to reduce emissions by 30% compared to 2005 levels by 2030. Canada’s current climate policies, such as a carbon tax, a phase-out of coal power plants and regulating methane emissions from the oil and gas industry will only get the country two-thirds of the way toward this goal.

During last year’s election, the current administration made several climate action promises geared toward ensuring that Canada met its Paris accord commitments, a 2016 agreement within the United Nations Framework Convention on Climate Change dealing with greenhouse-gas-emissions mitigation, adaptation and finance. Those promises included exceeding the country’s 2030 emissions target and achieving net-zero emissions by 2050. But little action has been taken in the last year. The International Panel on Climate Change (IPCC) determined that if global emissions reach net-zero by 2050, global temperature increases would be limited to 1.5 degrees Celsius. The Paris climate accord makes limiting temperature rise to 1.5 Celsius a central goal.

Additional measures are expected from the Canadian government in coming months, such as a national hydrogen strategy to identify potential uses for hydrogen as fuel and new standards for cleaner-burning fuels and sector-by-sector consultations reduction targets, according to recent news reports.

Read TWS’ Position Statement on Global Climate Change and Wildlife

TWS member works to make buildings safer for birds

December 3, 2020 by The Wildlife Society

TWS member Karen Powers is trying to make her community a little more bird friendly.

A wildlife biologist at Radford University, where she serves as the faculty adviser for the college’s student chapter of The Wildlife Society, Powers and her story have documented a rise in the number of birds colliding with the large windows on campus.

The college sits along the New River in southwestern Virginia, which serves as an important migratory flyway.

“They see the vegetation reflected; they see the sky reflected. They can’t perceive the difference like we can,” Powers told Radford public radio station WVTF.

In a recent story, the radio station reported on Powers’s efforts to reduce the number of bird collisions with windows. She’s been working with Sabrina Garvin, executive director of Southwest Virginia Wildlife Center in Roanoke, to make buildings safer for birds, whether it’s high-tech window films or children’s painting projects.

And they urge people to keep their house cats indoors. Worse than glassy buildings, cats are the “number one” killer of birds, Garvin says.

Read more from WVTF, or listen to the story, here.

Is ‘America’s Amazon’ in jeopardy?

December 2, 2020 by The Wildlife Society

The Mobile River Basin is the largest inland delta system in the United States and is among the world’s richest biodiversity hotspots, but it’s facing an array of threats it hasn’t seen before.

“This is America’s Amazon, far and away the most biodiverse river network in North America,” writes author Ben Raines, “far and away the most biodiverse river network in North America.”

Thanks to this region, Alabama is home to more species of freshwater fish, mussels, snails, turtles and crawfish than any other state, Raines writes, and more turtle species than any other river delta system in the world. But while its ecosystems have remained largely intact, that may be changing.

“Habitat destruction, development and lax enforcement of environmental regulations conspire to take an increasing toll, making the area a global hot spot for extinctions, particularly of aquatic creatures,” Raines writes in the Los Angeles Times.

These threats come as the scientific community is just beginning to realize the region’s richness. “Subdivisions and cities are spreading quickly across acreage long devoted to timber, agriculture or kudzu,” Raines writes. “With that growth comes the likelihood of accelerated destruction for what scientists have only begun to realize is one of the most diverse ecological areas outside of the Amazonian rain forests.”

Read more in the Los Angeles Times.