Scientists are calling for a new global system that would monitor biodiversity. Ideally, this system, dubbed the Global Biodiversity Observing System, would help researchers and conservationists track the problems caused by climate change and other threats to species around the world. “The lethal combination of habitat loss, the exploitation of natural populations, pollution and climate change is causing species extinction rates not seen since the last mass extinction 65 million years ago,” said Andrew Gonzalez, a conservation biologist at McGill University, and co-chair of the Group on Earth Observations Biodiversity Observation Network, in a press release. “We lack the means to monitor these impacts fast enough across most areas of the planet.” In a paper published recently in NatureEcology & Evolution, Gonzalez and his colleagues laid out the specifics of what such a monitoring system would look like.
The Arizona night lizard (Xantusia arizonae) is a hard creature to find. It appears only in that state—and in just a single county—and they hide inside narrow rock cracks in rugged territory. Despite the name, they’re not nocturnal, but their cryptic behavior makes it hard for researchers to know much about them. Ryan O’Donnell, a research biologist with the Arizona Department of Fish and Wildlife, has been leading a team searching for this unusual lizard, which unlike most reptiles, gives live birth.
For more on this cryptic lizard, watch the video below.
Researchers know that climate change is causing turtles to produce more females, but for some turtles, it may also cause them to produce more eggs.
In a recent study published in the Journal of Current Biology, researchers analyzed red-eared slider (Trachemys scripta) eggs under different incubation temperatures to see how the increase in temperature affects the reproductive potential of females.
The team found that there was an increase in the number of germ cells—a type of cell that provides embryos with the future ability to produce sperm or egg—under warmer temperatures. With higher temperatures leading to more female hatchlings, and rising germ cell counts increasing the females’ egg capacity, turtle population dynamics may move into uncharted waters.
Producing more eggs “improves female reproductive potential and provides an adaptive advantage,” researchers suggest.
This is especially important as the warming climate skews many turtle species’ sex ratios, raising questions about their future reproduction. Turtle hatchling sex is determined by temperature, and warming trends are resulting in more females in many species. A study in 2018, for example, found that 99% of new green sea turtles (Chelonia mydas) hatched in Australia were females. The National Oceanic and Atmospheric Administration has classified rising sand temperatures as a threat to leatherback sea turtles (Dermochelys coriacea) due to these conditions producing more female hatchlings.
Researchers used immunofluorescence to study the development of germ cells in red-eared slider embryos. Credit: Boris Tezak
Red-eared sliders are also producing more female hatchlings than males, but an ability to produce more eggs overall could offer benefits to the population, researchers found.
Past research focused on temperature effects on gonadal sex determination, but not on germ cells specifically, said Boris Tezak, a postdoctoral researcher at Duke University and lead researcher of the study. While having a skewed sex ratio is a conservation challenge, he said, having more female turtles than males is less of an obstacle than the opposite. Increasing the reproductive fitness of females may even be a positive thing for the endangered species, which faces other challenges linked with the climate crisis, such as habitat loss and shifting nesting seasons.
Tezak stressed the importance of long-term studies on this topic given the long lives of turtles and the slow pace of sexual maturation in some species. It will take generations of turtles to truly see how increasingly high temperatures affect the reproductive fitness and longevity of turtle species globally.
“If we have a better understanding of the molecular mechanism behind sex determination, then we can better predict how changes in climate and temperature will affect sex ratios going forward,” he said.
When people think of the effect of predators on the ecosystem, they usually think of their role in controlling prey, like wolves (Canis lupus) reducing elk numbers (Cervus canadensis) in Yellowstone National Park. But what if predators play another role that biologists have been overlooking?
By taking down prey, researchers found, predators can create ecological hot spots. The carcasses and other material they leave behind act as fertilizer for native plant species that can attract other wildlife.
Sean Johnson-Bice and Thomas Gable became interested in this phenomenon while studying wolves preying on beavers (Castor canadensis). Although the wolves didn’t reduce beaver numbers, they stopped beaver from creating dams in some places that would have reshaped the landscape.
“Wolves basically stopped beavers from converting forest into wetland,” said Gable, the project lead of the Voyageurs Wolf Project.
Researchers found that by preying on beavers in Voyageurs National Park, wolves were shaping the ecosystem. Credit: Thomas Gable
That got Johnson-Bice, Gable and their colleagues thinking about other effects predators could have on the ecosystem—effects on just isolated patches of the landscape. For the study published recently in Oikos, led by Sean Johnson-Bice, a PhD candidate at the University of Manitoba who has focused his research on Arctic foxes (Vulpes lagopus). Team members scoured the scientific literature for all the data they could find that pointed to what they termed PIEs—patchy indirect effects of predation.
“We were synthesizing virtually any study we could find from anywhere any place on the topic,” Johnson-Bice said.
The team uncovered many examples where they could trace ecosystem hot spots to predators, usually by either leaving behind carcasses, concentrating nutrients from prey or killing ecosystem engineers like beavers.
Cougar (Puma concolor) kills, for instance, impact beetle communities, which in turn impacts nutrient cycling. Arctic foxes bring back kills back to their young. What the kits don’t consume becomes plant food. So do the salmon carcasses left scattered by grizzlies (Ursus arctos horribilis).
“It’s like adding fertilizer to a garden,” Johnson-Bice said. The areas become “islands of vegetation that are totally different from the surrounding area.”
Predators may not always play a big role in reducing prey or changing their behaviors, he said, but they can help benefit the ecosystem in ways that are often overlooked.
“If we want to have functioning ecosystems—and ones that function well—predation is an integral part of that,” Gable said.
It isn’t easy counting sea turtle nests. Surveyors can spend hours searching for the eggs, which are sometimes buried three feet deep in the sand. But researchers discovered that for at least one species—the loggerhead sea turtle (Caretta caretta)—a detection dog in Florida was much more accurate and more efficient than its human counterpart.
But the results were based on just one dog, researchers cautioned. “Additional research is needed with multiple detection dogs and handlers,” they wrote.
But, as we explored in the March/April issue of The Wildlife Professional, detection dogs have been successfully deployed for all kinds of conservation purposes—from finding invasive species to sniffing out disease. Finding sea turtle eggs may be just one more.
The Biden administration has canceled the last of seven oil and gas leases in the Arctic National Wildlife Refuge sold by the Trump Administration in 2021.
“Canceling all remaining oil and gas leases issued under the previous administration in the Arctic [National Wildlife] Refuge and protecting more than 13 million acres in the Western Arctic will help preserve our Arctic lands and wildlife…,” the president said in a statement on the Sept. 6. The administration also announced that it would limit all new leasing in the National Petroleum Reserve in Alaska (NPR-A), the largest block of public land in the U.S.
In 2018, The Wildlife Society expressed concern over energy development in NPR-A in a letter to the Secretary of the Interior. The Society advocated for the “maximum protection” as provided by law for five special areas within the NPR-A due to its rich biodiversity. The NPR-A provides critical habitat for millions of migratory birds and large concentrations of marine mammals including beluga whales (Delphinapterus leucas), spotted seals (Phoca largha), and walrus (Odobenus rosmarus). Critical breeding grounds for two of Alaska’s largest caribou herds occur on the NPR-A. Special Areas within the NPR-A also provide critical feeding and denning habitat for polar bears (Ursus maritimus), grizzly bears (Ursus arctos horribilis), wolves (Canis lupus), and wolverines (Gulo gulo luscus).
The Arctic National Wildlife Refuge (ANWR), east of the NPR-A, includes 19 million acres of land with no roads, trails, or designated entry points. Like the NPR-A, ANWR is home to hundreds of thousands of caribou that migrate to the refuge to rear their young. It also serves as habitat for millions of migratory birds such as snowy owls (Bubo scandiacus) and steller’s eiders (Polysticta stelleri). The Arctic Wildlife Refuge is one of the few locations that is inhabited by polar bears, grizzly bears, and black bears (Ursus americanus). Muskox (Ovibos moschatus) herds are iconic to ANWR; their reintroduction to the refuge serves as a conservation success story. The species was restored to ANWR in 1970 after having completely vanished from Alaska by the 1890s.
The Arctic is warming twice as fast as the rest of the planet in the midst of the global climate crisis. Oil drilling will exacerbate the degradation of Arctic habitat caused by warmer temperatures, releasing mass amounts of carbon dioxide stored in untouched Arctic soils and further progressing the melting of glaciers and sea ice. Oil spills in the Arctic would also be devastating, resulting in the loss of critical food sources for thousands of marine mammals and seabirds. An oil catastrophe in ANWR would also deeply affect the Gwich’in and Iñupiat tribes, which depend on the wildlife of ANWR as a stable food source. There are still no proven methods to effectively clean an oil spill in this region.
The battle surrounding ANWR’s conservation versus energy development has been long, dating back to 1986 when the Reagan administration first recommended that it be opened to oil and gas development. In 2020, the Trump administration announced that the U.S. would auction off 22 tracts of land on the coasts of ANWR for oil and gas leasing; in 2021 only 11 of them were purchased at auction. Following President Biden’s inauguration, the new Secretary of Interior Deb Haaland suspended the purchased leases. Last week’s announcement from the White House made these suspensions permanent. Going forward, former ANWR leaseholder, Alaska Industrial Development and Export Authority announced plans to seek litigation against the president’s decision.
Just 40 or 50 years ago, the osprey was a rare species in New Jersey. Today, ospreys (Pandion haliaetus) a common sight at places like the Tuckahoe Wildlife Management Area. Recently, representatives from the U.S. Fish and Wildlife Service, the New Jersey Division of Fish and Wildlife and Henry Repeating Arms visited the marshland to survey and band osprey at the site. The effort was part of the Partner with a Payer program, an initiative of the U.S. Fish and Wildlife’s Wildlife & Sport Fish Restoration program, which seeks to strengthen ties with the manufacturers that fund wildlife conservation through excise taxes on firearms.
Researchers say they have been able to model population trends of more than 500 bird species in the U.S., determining whether populations are rising or falling even at the local level. The information, including detailed trend maps for each species down to an eight-mile radius, could help conservationists gauge how local populations are faring.
“One of the things that’s new about this analysis is the spatial resolution,” said Daniel Fink, senior research associate at the Cornell Lab of Ornithology and the lead author of the study published in Methods in Ecology and Evolution. “That sort of regional landscape information is very novel.”
Another unique aspect of the study is its focus. The study looks less at birds than it does at birders—the citizen scientists who contribute sightings to the Cornell Lab’s popular eBird app.
Citizen science can give researchers remarkable data, but the findings are subject to the accuracy of the participants. Since human behavior can be even more confounding than wildlife behavior, researchers at the Cornell Lab have had to wrestle with changes in how birders record their findings.
By using a type of artificial intelligence known as double machine learning, Fink and his team sought to account for year-to-year changes in the behaviors of eBird contributors.
“We’re trying to get as much information out of that citizen science project as we can and make it as solid as we can,” Fink said.
The eBird trends map shows wood thrush populations increasing in some areas but decreasing in others, allowing for targeted conservation planning. Credit: eBird/Cornell Lab of Ornithology
As people get better at identifying birds, go birding in new spots or get better tools to bird with, their reporting often changes over time. Those changes can affect abundance estimates for bird species. By looking for variations in bird counts and coupling that with variation in birders’ behaviors, researchers used double machine learning to screen out the behavior changes and better account for bird numbers.
The result, researchers say, is a set of highly detailed population estimates for a broad number of birds. The maps they created show variations within the same species across their ranges. Wood thrushes (Hylocichla mustelina), for instance, appear to be increasing in western populations but declining in the eastern U.S. Northern cardinals (Cardinalis cardinalis) showed declines in the south, gains in the north and falling populations around cities.
These detailed maps can give conservationists a better sense of where to focus their attention and look for what might be causing declines in specific areas, Fink said.
The technique could be applied to other citizen science programs, he said, to allow for more accurate estimates—particularly in spots on the map where more formal research is lacking.
When spotted lanternflies appeared in the U.S. from China, their arrival raised concerns about how these sap-feeding insects would damage both native and commercial trees. But researchers have found that some hardwoods, including maples, willows and birches, may be less vulnerable than initially thought.
“Since the lanternfly was first introduced to the northeastern U.S., the question has been, ‘How at-risk are our forests?’ said Kelli Hoover, professor of entomology at Penn State. “So far, we haven’t had a good answer. Our study is the first to look at the long-term impacts of feeding pressure on northeastern hardwoods, and our results suggest that we are unlikely to see big impacts on the growth of trees.”
Gulls can cause huge problems for wildlife managers in some cities. When they nest in large colonies near airports, these urban-adapted, roof-nesting birds pose a risk of collision with planes. In other areas, they may just make a mess or become a nuisance.
Wildlife managers often try to chase the birds off for the long term, but that’s not always easy.
“Some of this work is actually pretty dangerous for biologists to do,” said TWS member Morgan Pfeiffer, a research wildlife biologist with the U.S. Department of Agriculture’s National Wildlife Research Center. “I’ve heard stories of people falling through roofs.”
Species like ring-billed (Larus delawarensis) and herring gulls (L. argentatus) naturally nest on the ground in small, offshore islands free of predators. But they have adapted well to urban areas, especially along the ocean or in the Great Lakes region. There, they use rooftops to nest in large colonies—some with as many as 1,000 breeding pairs.
Pfeiffer and her colleagues decided to explore using drones to chase the gulls off from areas where they might create conflict or endanger humans.
For a study published recently in the Wildlife Society Bulletin, she and her colleagues tested whether drones could scare gulls from rooftops in Sandusky, Ohio, and near Chicago O’Hare International Airport in Illinois, getting them to leave the area before spring nesting season when they gather in large numbers.
A drone flies over a roof where gulls sometimes gather. Credit: USDA Wildlife Services
Night frights for night flights
They went first to Sandusky, flying a drone over a picnic shelter with a metal roof where gulls nested. They decided to test the method at night when gulls rest but easily get spooked, since predators like raccoons (Procyon lotor) and red foxes (Vulpes vulpes) usually attack them at this time.
“Gulls are actually ill-adapted to dealing with predators at night,” Pfeiffer said. “We wanted to see if we could scare them at night to enhance how scary the [drone] is to the gulls.”
The idea was that if they could make the place unsavory enough for them, the gulls may decide to build their nests elsewhere.
The trouble in Sandusky, they realized, was that the weather was often too windy or rainy to fly the drone. On clearer, calmer nights, the gulls weren’t always on the rooftop.
When the gulls were around, though, the drones did seem to scare them away. And they didn’t attack the flying machines, either, as they’ve been known to do.
Challenges in Chicago
In Chicago, the team had a different set of challenges. For one, their test site there was close enough to O’Hare that they needed extra authorization to fly.
Here, they tested the method against a colony of about 130 gulls, both herring and ring-billed. These city birds were reticent at first. “It took a few dive-bombing approaches before they felt the need to fly,” Pfeiffer said.
But finally, the whole colony took off into a cloud of birds. “It took almost 15 minutes of me flying up there back and forth, trying to defend the roof, for them to decide ‘Let’s move elsewhere.’”
The trouble was, they all just landed on a neighboring building. “From this perspective, we just moved the problem over,” Pfeiffer said.
The team had even more challenges—including a crashed drone at one point that fell out of the sky. But Pfeiffer still thinks the technique can be useful in cases where wildlife managers, or even building owners, want to move birds away from their building for a day or two.
And while the area around O’Hare would be difficult to work with due to the number of buildings around the airport, the technique may work in places with fewer ideal gull nesting locations. If scared off, they might go farther away to nest.
In the future, Pfeiffer hopes to see if flying the drones over gull colonies with eggs might make more of a difference. For this research, the team couldn’t fly drones once eggs were laid, since it would have required permits under the Migratory Bird Treaty Act.
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.
