When Falk Huettmann was conducting a study on urban ravens in Fairbanks, Alaska, he and his colleagues uncovered some findings about a totally different species—short-billed gulls.
When most ravens (Corvus corax) disappeared from the supermarket parking lots and other urban niches they occupied at the end of winter, the gulls simply took their place and stayed through summer. “The gulls are suddenly found where we find ravens for three months,” said Huettmann, a professor at the University of Alaska Fairbanks. The gulls were spending time on gravel pits and strip malls close to rivers until August.
Huettmann led a study published in Ecological Informatics using machine learning to find out more about short-billed gulls’ (Larus canus) urban habitat preferences in Fairbanks.
Gulls in general have become increasingly urbanized over at least the past 30 years as the landscapes they once used have been lost. Short-billed gulls historically lived in boreal forests, but they have been moving to urban areas.
To conduct the study, Huettmann and his colleagues surveyed 80 plots in Fairbanks for short-billed gulls, and citizen scientists shared data where they were finding gulls.
For the following two years, Huettmann and his team revisited 50 of the plots. Then, they modeled where the gulls showed up and added environmental data to the model to help make sense of the patterns. Using public GIS data, they were able to look at different layers of habitat availability and add a layer of human resources, like restaurants, that the gulls might take advantage of. Further, they included U.S. census data to see if socioeconomic metrics influenced gull presence.
“These big data get data mined with machine learning for patterns,” Huettmann said.
The model suggested that gulls tended to occupy areas that were close to rivers, as well as supermarkets and waste dumps.
Huettmann and his colleagues then did ground-truthing to see if the model was accurate. They went to specific hot spots where gulls were predicted to be abundant, like the parking lots of supermarkets and fast food restaurants, and found lots of gulls.
Their abundance at these sites can cause problems for both the birds and people. Consuming waste at restaurants isn’t natural or healthy for the gulls, and their proximity to humans raises the risk of spreading zoonotic diseases.
The government of Canada has pledged $3 million in funding to Birds Canada over five years to support citizen science programs, opening up hundreds of millions of records to help researchers study the population trends of birds in the country.
The funding is intended to aid the nonprofit organization in expanding its efforts gather data and monitor migratory birds, including species at risk. The funding will support Birds Canada’s NatureCounts platform, a citizen science program that collects information on wild birds throughout the country.
Those citizen science efforts “yield meaningful, accessible data to support conservation, thus contributing to halting and reversing biodiversity loss and protecting our beloved birds,” Patrick Nadeau, president and CEO of Birds Canada, said in a press release.
Researcher Joshua Pickering emerges from the dense vegetation that has emerged on Long Point. Credit: Michael Bradstreet
When Joshua Pickering looks out across Long Point, he can’t see very far. This narrow spit of land jutting into Lake Erie from mainland Ontario is crowded with a thorny jumble of native shrubs and trees that host a menagerie of both resident and migratory birds.
“You can’t see more than probably 20 feet in some areas,” said Pickering, a PhD candidate at the University of Waterloo.
That’s a far cry from the way this skinny peninsula looked in 1964 when researcher Michael Bradstreet first visited as a 14-year-old boy and fell in love with Long Point and its diverse bird life. It was like a city park then, Bradstreet recalled, “with big trees, no shrubs and a grass lawn. I thought that’s the way it was supposed to be. There were also a very large number of deer, which I also thought was the way it was supposed to be.”
That wasn’t the way it was supposed to be, though. Long Point’s white-tailed deer (Odocoileus virginianus) population was exploding. Overabundant deer were browsing any vegetation they could reach to nubs, chewing down anything less than six feet tall. Over time, the peninsula’s early successional forest gave way to a plane of grass and invasive plants. It was pretty, but it was also ecologically unhealthy.
This July 22, 1963 photo was taken at a time when Long Point had an open, parklike landscape due to overabundant deer browsing the vegetation. Credit: Wilford Peloquin
To try to restore the native ecosystem, the Canadian government embarked on a culling program to slash the herd’s size. As deer numbers dwindled, Long Point’s historical plant community resurged. By then, the boy who fell in love with Long Point had become a biologist, and Bradstreet and his colleague, Jane Bowles, set out on a mission. They would embark on a 30-year survey to document how the vegetation changed with fewer deer to gnaw it down. When Bowles passed away in 2013, Bradstreet vowed to complete the work.
In 2021, his three decades of fieldwork came to an end. He was joined in that final season by Pickering, who was working on his master’s degree at the University of Guelph at the time. The dataset was then passed on to Pickering, who synthesized the research in his master’s thesis and the latest Wildlife Monographs, completing the work Bradstreet began before Pickering was born.
“Michael was there since the start,” Pickering said.
The meeting point
Stretching 40 kilometers into Lake Erie, Long Point is the largest freshwater sand spit in the world. Credit: Ken Lund
A 40-kilometer-long stretch of land on Lake Erie’s north shore, Long Point is the largest freshwater sand spit in the world. Only a few kilometers across at its widest, it was once an island before the passing waves and shifting sands that formed it connected it to the mainland.
The narrow peninsula is home to a village of year-round residents and summer visitors, an iconic lighthouse and the nonprofit conservation organization Birds Canada, where Bradstreet got his start as a biologist when it was known as the Long Point Bird Observatory. The peninsula continues with the Long Point National Wildlife Area, a 3,284-hectare protected landscape of beaches, dunes, marshes and forests. The area hosts more than 80 species of birds that nest there and more than 300 different migratory species that stop at this first glimpse of land as they travel across Lake Erie.
A common yellowthroat (Geothlypis trichas) perches on a branch on Long Point, one of more than 300 migratory species found there. Credit: Brendan Ryan
“It’s the meeting point of two different biomes,” Pickering said, a place where trees more common south of the border, like tulip poplars, join northern species like white birch.
White-tailed deer historically roamed this landscape, as did elk (Cervus canadensis) and black bear (Ursus americanus). Unregulated hunting eliminated those species, but in 1874, the Long Point Co., which owned most of the peninsula as a private waterfowl hunting club, reintroduced 15 deer. Without predators or sustained hunting, the deer population soared.
“By 1920, they were really overabundant,” Pickering said of the deer. At their height, their numbers reached more than 500—a lot of deer for a tiny spit of land. A healthy population is considered fewer than five deer per square kilometer. Densities on Long Point topped 65 per square kilometer. As the deer surged, the vegetation suffered.
“Without predator and hunting pressure, and with seemingly unlimited forage, they started browsing it to nothing,” Pickering said.
‘A devastating effect’
Researchers Michael Bradstreet, left, and Jane Bowles, right survey the vegetation on Long Point. Credit: André Lachance
When the Canadian government established the Long Point National Wildlife Area in 1978, deer emerged as the key disturbance to the area’s vegetation. When the Canadian Wildlife Service (CWS) set up a series of fenced areas in the mid-1980s to keep deer out of certain patches, the ungulates’ effect was obvious.
“It was pretty clear that deer were having a devastating effect on regeneration,” Bradstreet said.
To help the vegetation recover, the CWS teamed up with local hunters to conduct a massive culling effort. Between 1988 and 1991, the program eliminated over 500 deer, reducing the population by over 85%. Bradstreet and Bowles wanted to see how the plant life responded.
In the early 1970s, Bradstreet had worked at the observatory, where he helped set up a breeding bird census on Long Point. After leaving for 14 years working in the Arctic for an environmental consulting firm, he returned to the bird center in 1989. There, he resumed the census and launched a new project—to document the changes in the landscape over the next three decades. It was a daunting proposition for a 40-year-old researcher.
“If you’re going to design a strenuous 30-year study, do it when you’re 20, not when you’re 40,” Bradstreet said with a laugh.
The forest returns
With fewer deer on Long Point, its early successional forest has returned. Credit: Michael Bradstreet
Over the ensuing decades, Bradstreet and Bowles—an adjunct biology professor at The University of Western Ontario—spent springs and summers trekking across dunes, wading through wetlands, ducking thunderstorms and fending off ticks, mosquitoes and biting flies.
With a steady stream of collaborators—paid and unpaid—they gathered more than 800,000 vegetation measurements from 15 plots on Long Point, focusing on the woody shrubs, trees and vines that deer prefer. Over that period, radios and film cameras gave way to smartphones. Compass readings were replaced with GPS tracking. Laser measurements took the place of ropes and tape.
The changes they observed came slowly at first. For the first three years, Bradstreet and Bowles didn’t see much difference at all. But ongoing managed and public hunts kept deer numbers down to about 60 over the following decades, and the vegetation responded.
“Plots which originally contained few plant species or stems had over time shifted to support dozens of species and sometimes hundreds of stems,” Bradstreet wrote in a recent email to colleagues.
Between 1995 and 2021, woody stems above the 6-foot browse layer increased a massive 1,500%. Grasses, which deer tend to not eat, gave way to species like trillium and white pine, which they prefer. Native plants dominated the landscape again, crowding out exotic species. Species richness and diversity climbed. Over time, Long Point transformed into an early successional forest again.
Changes over time
Deer remain on Long Point, but in much fewer numbers than they once did. Credit: jeremybarker via iNaturalist
Bradstreet and Bowles could see it on the ground. When Pickering inherited the project and analyzed the numbers, he could see it in the data, too.
At the end of the project, Bradstreet was 71, and he felt it was time to turn it over to someone sprier in the field and more adept at statistical modeling programs. A lot can change over a 30-year research project. Bradstreet left Birds Canada for the Nature Conservancy of Canada, where he started as regional lead before retiring as senior vice president for conservation. “It was great to spend the last part of my career protecting nature—actually physically buying land,” he said.
Bowles, who grew up in Kenya and studied in England before completing her PhD at the University of Western Ontario, became the curator of the university’s herbarium and director of its arboretum, in addition to teaching classes in plant science and zoology. She saw the changes taking place at Long Point, but she wouldn’t live to see the full transformation. In 2013, she died of cancer. Bradstreet promised to see the project through.
“For me, it’s nice to see this all wrapped up in a bow and I feel that my commitment to Jane is now fulfilled,” Bradstreet wrote.
For Pickering, it was a rare chance as a master’s student to work with a lifetime’s worth of data. Now a PhD candidate at the University of Waterloo, he’s continuing the breeding bird work Bradstreet began in the ’70s when Long Point was still a park-like area overrun by deer. After documenting how the landscape has transformed, Pickering’s next challenge is to see how birdlife has changed.
“Overabundant deer really do hinder biodiversity in the vegetation community,” Pickering said. “Hopefully, we’ll find that in the next few years in the breeding bird community as well.”
Researchers are exploring if gut bacteria could help identify wildlife with chronic wasting disease.
In a study published in Microbiology Spectrum, researchers analyzed fecal samples from white-tailed deer (Odocoileus virginianus) from different regions of the U.S. They found CWD-positive deer showed changes in their microbiome before outward symptoms appeared. The researchers hope that could lead to a way to test for the disease in live animals.
“This work is the start of a very promising trend to use fecal samples to both identify the disease and also learn more about the biology of the disease,” said Anna Kashina, professor of biochemistry at the University of Pennsylvania School of Veterinary Medicine.
CWD is a fatal prion disease that affects cervids including deer, elk and moose and can spread quickly between animals.
You can have deer that are infected live for two or more years, and it can take a very long time before they show clinical signs of it,” says Michelle Gibison, diagnostic laboratory testing manager at Penn Vet’s Wildlife Futures Program. Because there’s no noninvasive way to test live animals for the disease, that time lag allows for more chance for CWD to spread.
Getting funding can be one of the hardest parts of conserving wildlife, and often, those funds come with stipulations about where conservation work can take place. But sometimes the needs are even greater just over the state line or in the next watershed.
In a paper published in Frontiers in Ecology and the Environment, researchers looked at how a little more flexibility could make public and private conservation dollars go farther. We caught up with lead author Paul Armsworth, a professor at the University of Tennessee Knoxville, to talk about the findings. His responses are edited for brevity and style.
What motivated you to look at how to use funds for wildlife conservation in a better way?
One of the big challenges we face in conservation is that the places with the most resources to support conservation are not the same places where conservation action would have the greatest impact.
That’s true regardless of what objectives you choose. Is it about protecting all species? Vulnerable species? Ecosystem services? It doesn’t actually matter. As you look across different objectives, the highest impact opportunities are not the places where we have the most resources. That can be public resources or private resources.
That challenge, I think, epitomizes lots of aspects of conservation within individual states here in the U.S., but also globally.
Where is the disconnect in places chosen for conservation funding and where conservation should take place?
We have a situation whereby donors—or, on the public funding side, politicians—are looking after their constituencies. They’re looking for conservation in their backyard. They want nearby projects that they can connect to their local public.
But if the resources are concentrated in some parts of the map, that would lead to natural resource conservation or management actions being concentrated in places that aren’t necessarily the best opportunities we could have. So we could be stuck there.
Or we can listen to some of the voices that conservation science has had for decades. That sort of clamor of “you should trust me and my algorithm, and I will tell you the best place to conserve.” That’s a useful contribution, but it hasn’t moved people.
We’ve been stuck at those two poles. It’s either conservation being concentrated in the place with the resources or scientists saying, “but over here is a really good opportunity.” We want to find a way to move this discussion forward. The way to do it is not just to say, “What could we do if we had perfect flexibility?” Instead, the way to do it is to think about where people are today—to respect their autonomy as decision makers, to respect the private donors and what they’re excited by, to respect the politicians and their catering to multiple needs. Find them where they are and try and come up with a way to put data into their hands that would show what could be done with funding if you allow a little bit more flexibility.
What are some examples where funding is too rigid?
You can see it in federal-to-state granting policies that have formulas for how funding should be allocated across states. For example, the Land and Water Conservation Fund provided funding on an equal basis across states and other funding based on a state’s population relative to the U.S. population, with a restriction that no one gets more than 10% of the funding. That leads to a very distributed pattern of funding allocations.
If we’re looking at biodiversity, it’s not as distributed as that. There are some places in the country where we can have a higher impact than others due to the distribution of species—particularly vulnerable species. It also has to do with how much it costs to secure land protection in different places.
Can you explain your grocery store analogy?
You’re going to the grocery store and you’ve got $150 to spend. You’re told to do the best you can for your family. You would go and pick some items that you and your family love or would work for you. Now imagine if I said, “You need to spend $10 in every single aisle.” You might not have pets, or you might not have young kids, but you’re going to have to spend some money in the pet section and the baby section. It doesn’t make sense. And that’s how some of these restrictions limit conservation actions. Actions will be much more effective at delivering on a conservation program’s goals if they can be targeted towards places where they will do most good for biodiversity or benefits to people from nature.
What might better flexibility look like?
It’s not total flexibility. It’s a little bit of flexibility, looking at projects not right in your backyard but in your neighborhood, or in the watershed you share with a neighbor. Here in East Tennessee, if I reached across the border to North Carolina or Virginia, how would that change the impact that I could have? It’s not just immediate geography either. Migratory species provide another shared ecological focus that people can be asked to come together to support.Our approach and our tools were designed to enable those comparisons to be made by the people who are providing resources and making these decisions.
What are some ways you influence a private donor’s decision to make a bigger impact?
Donors have very different motivations. Some really would only be motivated by projects that directly impact their community, and that’s absolutely fine. Our tools probably wouldn’t help them. But other donors want to see some analysis of what they could achieve right in their backyard versus what they could achieve 50 or 100 or 200 miles away. We’ve tried to think about what those individuals might want, and we developed some tools and approaches that might help build out those comparisons.
We provide an example of what a philanthropy officer at an NGO might want to take to talk to a donor. In our example, a donor in eastern Colorado is interested in conserving vulnerable biodiversity but also benefiting people. So we talked about some benefits to people. We then went through and quantified what they would get if they kept the money in eastern Colorado versus if they let it move across to shortgrass or tall grass prairie habitats shared with neighboring states.
How can we move the needle in making public funding less restrictive?
Some of these programs have two pieces. They have a fixed formula, but they then have another piece that’s often a competitive formula with a bit more flexibility built in. It’s not that public policies are not movable. It’s that you need to think about which aspects of policy you can have traction over. It’s that spirit of meeting people where they are and then moving the margin a little bit.
Climate change will usher in more invasive plants to the much of the eastern United States, according to a recent weed management study. That’s not just bad news for gardeners. The study finds it will harm ecological communities and have socioeconomic impacts.
“In some regions, hundreds of new, potentially invasive species could establish in coming decades,” wrote researchers in Invasive Plant Science and Management.
The study looked particularly at mid-Atlantic and northeastern states. It assessed the risk posed by 104 invasive plants expected to establish themselves in the region, including 46 that could impact agriculture, the economy and human health.
Assessing these risks could help “mitigate the greatest amount of potential damage,” researchers found.
Joking around is an important part of human interaction. Babies tease each other as young as eight months old. But what about animals? Since teasing doesn’t require language, do animals do it, too?
In a study of great apes, researchers found playful teasing in four different species— orangutans (Pongo spp.), chimpanzees (Pan troglodytes), bonobos (P. paniscus) and gorillas (Gorilla spp).
“Great apes are excellent candidates for playful teasing, as they are closely related to us, engage in social play, show laughter and display relatively sophisticated understandings of others’ expectations,” said Isabelle Laumer, postdoctoral researcher at the University of California Los Angeles and the first author of the study published in Proceedings of the Royal Society B.
The team analyzed actions that appeared to be playful or provocative and assessed the attitudes of the both the teaser and the target.
“We hope that our study will inspire other researchers to study playful teasing in more species in order to better understand the evolution of this multi-faceted behavior,” Laumer said. “We also hope that this study raises awareness of the similarities we share with our closest relatives and the importance of protecting these endangered animals.”
Watch the video below, and read the study in PNAS.
Ornate box turtles stay underground when the temperature is too cold—but they still pay attention to the time of year when deciding when to hibernate.
This new information on hibernation habits at the north of these reptiles’ range is useful for wildlife managers to avoid unnecessarily sacrificing turtles when prescribing fires.
“The best predictor was not just date, and not just temperature, but an interaction between temperature and date,” said Devin Edmonds, a PhD candidate at the University of Illinois Urbana-Champaign.
A radiotracking receiver sits next to a site where a turtle was detected, marked by a flag, underground. Credit: Devin Edmonds
The Illinois Department of Natural Resources (IDNR) prescribes fires in parts of Illinois to maintain ecosystem health and maintain a somewhat natural burn cycle. These fires may occasionally kill ornate box turtles (Terrapene ornata), whose populations are splintered in the northern end of their range in these areas.
“There’s just not a lot of habitat left for them,” Edmonds said.
But if the IDNR burns at the right time, the turtles will still be underground hibernating, where they are usually safe from the flames.
For a study published recently in the Journal of Wildlife Management, Edmonds and his colleagues wanted to learn more about the temperatures and dates ornate box turtles went underground in the fall, and when they emerged from their burrows in the spring. They hope this information can inform the IDNR about the safest times to burn to avoid turtle deaths.
A photo showing the recovery of the ecosystem (right) after a prescribed burn (left). Credit: Devin Edmonds
Turtle tracking
The team attached radio-transmitters and temperature loggers to the shells of 30 turtles they captured in three study areas in northeastern Illinois. They then went out turtle watching in the spring and summers from 2019 to 2022, verifying whether the turtles were underground or moving about. They also stuck temperature loggers into the soil at different depths in these areas. Finally, they pulled temperature and rain data from weather stations in the areas.
The researchers then compared the weather data with the time that the turtles had gone underground in the fall, and when they had emerged from hibernation in the spring.
They found that the amount of precipitation and soil temperature didn’t really predict hibernation timing for turtles.
Ornate box turtles are at the northern end of their range in Illinois. Credit: Devin Edmonds
Air temperature did seem to have an impact on hibernation times. But it wasn’t the only factor—the date seemed to matter as well. In other words, even if it stayed warm way into the winter, the turtles would still hibernate, though there was some leeway.
Just the same, they wouldn’t come out of hibernation too early, even if the temperature warmed up a lot sooner than normal. In some cases, they would come out a little early. Similarly, when the spring was chillier, the turtles sometimes stayed in hibernation a little later.
This may make things a little complicated for the IDNR when considering the best burn times. Edmonds said that it will likely need to consider both factors—air temperature and calendar date.
The consideration is important due to the fact that ornate box turtle habitat has become so fragmented at the northern end of their range. When fires burned hundreds of years ago, Edmonds said that a few turtles likely died without influencing the overall population. But soy and corn crops have largely taken over much of this part of Illinois, leaving turtle populations isolated and more vulnerable to fire.
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Ecotourism activities involving handling and photographing black caimans may cause the animals stress in the Amazon.
Caiman viewing is a popular activity for tourists in the Amazon, including in Anavilhanas National Park in the central Amazon region of Brazil. The activity often involves capturing live caimans, handling them and taking flash photography.
Washington Mendonça, an adjunct professor at the Federal University of the Amazon in Brazil, and his colleagues wanted to see whether this activity had any physiological effect on black caimans (Melanosuchus niger) and spectacled caimans (Caiman crocodilus). They published their findings in the Journal of Wildlife Management.
Night shift
In September and December of 2019, the team detected caimans at night in seasonally flooded forest by shining spotlights from a boat. They captured smaller caimans as these were the kinds usually captured by guides. They caught both black and spectacled caimans using special tongs from 7 p.m. to midnight, so they were at a similar part in the circadian rhythm. That would also mean similar corticosterone levels—a common indicator of stress. After extracting blood from the captured caimans, the researchers held them in different positions similar to the way a tour guide poses them for photos. They took flash photos of some of these caimans, before extracting another blood sample. With other caimans, the researchers just handled them without taking photos.
Washington Mendonça holds a handful of young caimans. Credit: Marcos Soney
In the lab, the researchers analyzed these blood samples to see how the corticosterone had changed after handling, taking photographs or both. The results showed that these tourist activities mostly affected black caimans but had little effect on spectacled caimans.
In black caimans, which are more of conservation concern than spectacled caimans, Mendonça said, corticosterone levels increased 1.7-fold, on average, when the animals were handled but not photographed. The levels increased 2.7 times when they were photographed using flash but not handled, compared to a control group. Lactate, another marker of stress, also increased in black but not spectacled caimans when researchers used flash but didn’t handle them.
Other research has shown that black caimans may have vision more similar to American alligators (Alligator mississippiensis) than other caimans. In effect, their eyes may be more sensitive to light, which may explain why the flash, but not handling, increased the stress of black caimans—but Mendonça said his team didn’t directly test this idea.
A tour guide holds a caiman for photos in the Amazon. Credit: Eli Duke
Contrary to what researchers would have thought, corticosterone levels did not increase more when any caimans were both handled and photographed at the same time, rather than just one or the other. “Short‐term interaction with this Amazonian crocodilian is stressful,” the researchers wrote about black caimans in the study. “Knowledge of the effects of this activity on the crocodilians is important for planning tourism and possibly for the conservation of the target species.”
In the long term, repeated handling may cause chronic stress in some individuals, the writers continued. This is concerning as some guide outfits conduct these kinds of operations quite often in some areas. Ecotourism operations in the area might improve the health of caiman populations by focusing less on black caimans than spectacled caimans, since the latter seem to cope better with handling and flash photography, they said.
The researchers only handled and photographed the caimans for about two minutes in this study. As a result, Mendonça cautioned that it’s possible that black, and even spectacled caimans, might experience more stress if handled for longer periods.
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.
A United Nations report found more than a fifth of the world’s migratory species are at risk of extinction. The first-ever report from the U.N. Convention on the Conservation of Migratory Species of Wild Animals found that 44% of migratory species have seen their numbers decline and 22% could disappear altogether due largely to climate change and human encroachment. Seventy-five percent were experiencing loss of habitat.
The report “clearly shows us that unsustainable human activities are jeopardizing the future of migratory species—creatures who not only act as indicators of environmental change but play an integral role in maintaining the function and resilience of our planet’s complex ecosystems,” said Inger Andersen, executive director of the United Nations Environment Program. Read more from Reuters.
