Land-use change has historically been the biggest driver of biodiversity decline, but researchers found that it may be overtaken by climate change by the middle of the century.
In a study published in Science, scientists estimated that global biodiversity declined by 2 to 11%, largely due to land-use changes. Land-use policies could reduce those declines in the future, they found, but “negative impacts on biodiversity due to climate change appear poised to increase.”
“We found that climate change poses an imminent threat to biodiversity and ecosystem services. While land-use change has historically been a significant factor, our findings indicate that climate change could overtake it as the primary driver of biodiversity loss by mid-century,” explains study coauthor David Leclère, a researcher in the International Institute for Applied Systems Analysis Integrated Biosphere Futures Research Group.
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Beavers have made a substantive comeback in North America after almost being wiped out due to the fur trade. But as they’ve returned, the landscape around them has changed. In the May/June issue of The Wildlife Professional, we explore the complexities of managing beavers where they are impacting city infrastructure, but also conserving them where they can benefit ecosystems.
In conjunction with this cover story, we are releasing a special issue of TWS’ journals, which compiles scientific articles published in the Journal of Wildlife Management and the Wildlife Society Bulletin over the past 20 years discussing beaver conservation and management.
Our cover story is paired with a special focus on our profession’s discipline of wildlife damage management.
Other articles focus on a program to get women into hunting, how one wildlife professional adapted her wildlife career after a traumatic brain injury, and a novel way of using laser scarecrows to deter birds.
Watch for the issue in your mailbox, or log in and check it out online.
Sea lions have been a popular tourist attraction in San Francisco since 1989, when they started gathering at Pier 39 in Fisherman’s Wharf. But recently they’ve been showing up in numbers not seen in 15 years. Biologists say a spike in anchovies, which the California sea lions (Zalophus californianus) eat, has brought more than 1,000 pinnipeds to the harbor.
It’s all about the food,” said Pier 39 harbormaster Sheila Chandor. “A very good way to put it is they are fueling up for the mating season. It’s spring. They are ready to rock and roll down in the Channel Islands, and we’re a nice pit stop with some great seafood.”
Conservation work can seem like an uphill battle, but a recent study concluded that actions around the world—particularly those targeted at species and ecosystems—really are making a positive impact on biodiversity.
In a global meta-analysis of 186 studies, researchers found that in two-thirds of the cases, conservation efforts had a net positive effect, either improving the state of biodiversity or at least slowing declines. Efforts targeted at species and ecosystems, such as invasive species control, habitat loss reduction and restoration, protected areas and sustainable management, are the most effective and have the largest effect sizes.
But to truly address the global biodiversity crisis, the study published in Science concluded, those efforts must be scaled up, with “additional investment across many sectors of society, particularly beyond the traditional conservation sector.”
Researchers uncovered hot spots in the Tennessee Valley where ospreys that nest on transmission poles and towers are more likely to cause power outages, fires, bird deaths and even human injury.
Power line managers can use this information to better mitigate conflict and improve safety for birds and people alike.
“I think it’s a very exciting thing to be [using] this proactive approach,” said Natasha Murphy, a scientific and technical officer at the Ireland Marine Institute, a government science agency in the country.
For some ospreys, tall transmission towers or power line poles seem to be an ideal place to build their nests, which are typically large and full of sticks and other debris. But the contents of those unruly nests can fall onto power lines, creating electrical currents that can cause a fire or outage. Osprey (Pandion haliaetus) droppings or wet nests can even cause a “flash over,” when they hit transmission lines and “launch an arc of fire,” she said.
Not only can these incidents endanger human lives and cost lots of money and effort to mitigate, but birds also face consequences. They can become electrocuted, and their nests can burn. “If there was a power outage, there could be a dead osprey under that tower,” Murphy said.
Bird transmission
The Tennessee Valley Authority (TVA), a federally owned electric utility company, wanted to learn more about how osprey habitat might overlap with transmission lines and other infrastructure in its service area, which includes seven states: Virginia, Tennessee, Mississippi, Alabama, North Carolina, Kentucky and Georgia. In a study published recently in the Journal of Wildlife Management, Murphy, who was a PhD student at Mississippi State University at the time, partnered with TVA to identify potential hot spots where osprey habitat and power transmission overlap.
She and her colleagues gathered osprey nest sighting data from eBird, a citizen science database that collects bird sightings. They then compared osprey sightings in the TVA area to data on the location of above-ground transmission lines overseen by the U.S. Department of Homeland Security. They also characterized the ecosystem surrounding osprey nests to understand more about their habitat suitability. The team used these three components—sightings, power infrastructure and habitat suitability—to model a map that highlighted areas of potential elevated conflict. The team fine-tuned their models by checking the databases of known osprey conflicts that TVA and the U.S. Department of Agriculture recorded.
They uncovered areas where the density of above-ground transmission lines overlapped with high habitat suitability. These high conflict areas included places like Knoxville, Tennessee and its surrounding area, for example. The city’s riverside location and high density of transmission lines make it a potential conflict hot spot, according to the models.
Murphy cautioned that other high-risk areas might have been left out of their study. Research has shown that the raptors may nest up to 20 kilometers away from the water sources where they typically feed. As a result, a proactive search for potential risky transmission lines would have to take this behavior into account.
An osprey sits on a nest on an electricity tower. Credit: NAME
Anticipating conflict
Overall, TVA and other utility companies can use this model to predict areas where they might see osprey electrocution, osprey-caused fires or other damages. These predictions could help managers better allocate efforts to retrofit transmission poles and towers and make them safer for osprey nests. The findings can also inform where to remove nests or implement hazing efforts to scare off nesting pairs, for example.
The models, “help people to proactively find the conflicts” so they can make informed decisions, Murphy said.
She said this model could also be used for other species that nest on power line infrastructure. In addition, it could help scientists determine points of potential wildlife conflict on other linear structures, like roads.
Osprey populations don’t appear to be struggling in these areas. But, Murphy said, it’s also difficult to determine their state, since nobody has studied how many of them are killed on power lines. She hopes that future studies might fill in these knowledge gaps.
“We don’t fully know the impact of those electrocution-related deaths, and those fire-related deaths on the osprey themselves,” Murphy said.
This article features research that was published in a TWS peer-reviewed journal. Individual online access to all TWS journal articles is a benefit of membership. Join TWS now to read the latest in wildlife research.
The ballot for The Wildlife Society’s 2024 elections includes nominees for the position of Southeastern Representative to TWS Council.
Electronic ballots will be sent May 29 to all members with an email address. Members without an email address will receive a paper ballot in the mail. Voting will close June 30. Mailed paper ballots must be postmarked on or before June 30. In accordance with TWS’ Bylaws, newly elected council members are scheduled to be installed at the next regular meeting of Council during the 31st Annual Conference, Oct. 19-23, in Baltimore, MD.
The candidates’ statements expressing their vision for The Wildlife Society and their interest in running for this council position are below.
The Southeastern Voting District includes all TWS members who reside in these geographic areas: Alabama, Arkansas, D.C., Florida, Georgia, Kentucky, Louisiana, Maryland, Mississippi, North Carolina, Puerto Rico, Oklahoma, South Carolina, Tennessee, Virginia
NOMINEES FOR SOUTHEASTERN REPRESENTATIVE TO TWS COUNCIL
Eric Pelren
As a member of The Wildlife Society for over 36 years, I have benefitted profoundly in many ways, both personally and professionally, from its many services. I am fortunate to be in a position that allows me to be active at all levels that the Society offers. As advisor to a student chapter, I am honored to mentor upcoming professionals, and I am impressed every year at the Southeastern Wildlife Student Conclave, and at the Southeastern Association of Fish and Wildlife Agencies Annual Conference, with the caliber of students across our Section. In 2015-1016, I served as Southeastern Section Historian; in this capacity, I delved deeply into Section records and was humbled by the depth, integrity, and impacts of our actions. From our participation in the formation of the Endangered Species Act, to our influence on proposed federal funding of wildlife conservation, to our commentary regarding professional standards and formation of a certification process, the Southeastern Section has been a force that is exemplary and motivational to me. I would be proud to represent the Section as our representative to Council.
I have been involved with teaching and research in wildlife for many years. I strongly believe it is important to give back to the profession and encourage current and future wildlife biologists to continue the great work of TWS. I am passionate about including diverse voices as I know wildlife conservation issues faced tomorrow will require many different ways of thinking. I know it is important to participate and for everyone to make their voices heard. I want to promote communication and collaboration in the profession. I also encourage wildlife professionals to engage the public and explain the science and thought that goes into management decisions.
Solutions to conservation issues and progress in natural resource management will come from an informed and passionate membership. I believe TWS provides many opportunities for professional growth and I will continue to advocate for education, training, and mentorship. I have been very fortunate to have had great guides, colleagues, and friends at all levels of TWS. I would like to be a part of the tradition and promote involvement. I welcome interactions, ideas, and suggestions from all members. If reelected, I will do my best to continue to serve the Southeast Section.
Traffic noise can affect birds even before they’re hatched, researchers found. In a study published in Science, researchers found that even moderate levels of traffic noise impacted the birds long-term development and fitness.
In an experiment, the authors exposed wild zebra finches to recordings of moderate traffic noise, as well as zebra finch songs and silence. The birds exposed to traffic noise experienced impaired nesting growth, shorter telomere length and reduced fitness as adults.
“The findings suggest that the acoustic environment of breeding birds in cities and along highways should be better managed,” wrote Hans Slabbekoorn, a professor at Leiden University, in the Netherlands, in a related Perspective. It could even have implications for humans, he wrote. “The acoustic comfort in hospital environments for pregnant mothers and babies warrants special attention.”
Great gray owls, once thought to spend most of their time in the Alaskan wilderness far from people, actually spend much of their time in human-populated areas.
There’s a “magical, mystical belief” about owls spending their time in the wild, said Falk Huettmann, a professor of wildlife ecology at the Institute of Arctic Biology, but 100 years of public data show gray owls (Strix nebulosi) regularly appear alongside humans.
Huettmann led a study published in Scientific Reports using publicly available data to determine where great gray owls occur and spend their time in Alaska. “Alaska doesn’t have so much public bird information shared,” he said, so his team spent years compiled sighting data from a variety of sources, including the biodiversity data site GBIF.org, citizen science platforms like eBird and iNaturalist, birdwatching email lists and Federal Aviation Administration bird strike records. The researchers wanted to look at as many factors as they could to predict where the birds are found. Most wildlife computer models take into consideration about 10 predictors, Huettmann said. But his team wanted to be more holistic using 100 predictors, including factors like climate, land cover, socio-economics and elevation.
Thanks to industrial grant funding, his team was able to tap into supercomputing time to create a first and massive data model to determine great gray owl hot spots in Alaska. The findings were contrary to conventional local wisdom. Great gray owls appeared wherever humans were, including industrial areas, cities, roads and farms. Wilderness areas, it turned out, weren’t even very good places to find the owls. “If you want to find them consistently,” Huettmann said, “you would probably be better advised to search in a fragmented farming environment,” where roadkill is common and open landscapes make it easier for them to perch and to find food.
“This somewhat flips the classic understanding of great gray owls,” he said. “It’s not this remote wilderness species as such. It lives in the Anthropocene.” That matches what is known about the birds elsewhere in their range in the Lower 48, Europe and Asia. The team conducted some ground truthing to see if these hot spots truly were in the areas they found. Looking at data and evidence from other studies, they found about a 90% match between those findings and their model in confirmation.
Huettmann hopes the paper can help with conservation priorities for the owl and serve as a guide for researchers studying other wildlife. “It’s a generic workflow that you can apply to any species,” he said.
Fireflies are an iconic part of summer nights in much of North America, but their glow is fading. In a study in Science of the Total Environment, researchers looked at what is impacting their populations and found a number of shifting environmental and human factors.
Members of the beetle family, the insects thrive in temperate weather with wet, warm summers and cold winters. But rising temperatures and changes in precipitation are affecting their life cycles.
“Subtle changes in climate patterns, especially related to temperature, are significantly impacting firefly breeding cycles and habitat quality,” said principal investigator Darin McNeil, associate professor at the University of Kentucky Department of Forestry & Natural Resources.
Other factors, including artificial lights, urban growth and the use of pesticides and herbicides may also play a role.
To study these population changes, the research used a mix of field surveys from citizen scientists and advanced machine learning techniques to analyze over 24,000 surveys from the Firefly Watch citizen science initiative.
To better understand the issue, researchers said, more species-specific research is needed.
“This approach will be crucial in ensuring that future generations can also enjoy the natural wonder of fireflies lighting up the night sky,” McNeil said.
Darwin Harbor has had a crocodile problem since the city was founded.
Northern Australia’s biggest city sits smack dab in the middle of an assortment of reserves, national parks and other wild areas filled with waterways and wetlands perfect for saltwater crocodiles.
As a result, the Northern Territory government traps and removes an average of 250-300 crocodiles per year from the beaches and waters of Darwin Harbor in an effort to limit the risk of attacks on humans in the area. But the effort is labor-intensive and costly.
Yusuke Fukuda, a researcher with the Northern Territory’s Department of Environment, Parks and Water Security, wanted to find out a way to stymie the numbers of crocs that reached the waters around the city by finding the source of their population.
Credit: Yusuke Fukuda
Fast recovery
Saltwater crocodiles (Crocodylus porosus) were hunted to near extinction in some parts of Australia in the early 1900s. After the Australian government put protections on the species in 1970, the crocodile numbers in the Northern Territory grew from about 3,000 to more than 100,000 now. “For a big animal, they’ve bounced back fairly spectacularly in terms of numbers,” said Sam Banks, director of the Research Institute for the Environment and Livelihoods at Charles Darwin University in Darwin, Australia.
They’ve done so well that the fashion industry now takes some of the eggs from the wild to raise and harvest the animals and produce crocodile skin boots, handbags and other goods. Banks, Fukuda and their colleagues wondered whether they could direct these harvesting efforts to certain areas that produced many of the crocodiles that cause human-wildlife conflict in the city.
Credit: Yusuke Fukuda
In a study published recently in the Journal of Wildlife Management, between 2015 and 2017, they began taking tissue samples from crocodiles removed from Darwin Harbor. The researchers analyzed the DNA and compared it with samples from eggs and live crocodiles from all around northern Australia, Papua New Guinea, East Timor, Cambodia, Indonesia, Malaysia, New Caledonia, Singapore and Vietnam.
“Basically, every time we get a crocodile in Darwin Harbor, we can pinpoint the genetic origin of that animal,” Banks said.
Credit: Yusuke Fukuda
The source of the problem
The analysis revealed there were no international travelers, but the crocodiles didn’t just come from one or two small source populations. “They definitely all came from the Northern Territory of Australia,” Banks said.
Credit: Yusuke Fukuda
Most of them come from places within 100-200 kilometers of Darwin, like Kakadu National Park. Some even came from much farther away, like Arnhem Land—one may have swum 700 kilometers to reach Darwin.
“They do move pretty widely,” Banks said.
Credit: Yusuke Fukuda
Some crocodiles that reach Darwin Harbor are large—the biggest male among those the team tested was more than 4 meters long. But most are much smaller, in the 1- to 2.5-meter range. Banks said that most of these are likely subadults that get pushed out of their natal lands.
“Crocodiles have recovered so well that it’s probably fairly difficult for young crocodiles to find new territory,” Banks said, adding that some may just bounce along the coast until they find Darwin Harbor.
In some ways, the removal of crocodiles is probably what’s making Darwin Harbor so appealing, as it seems like the perfect place to settle down for these itinerant young crocs. It always seems like a great place since it’s free of big, older crocs. “But it’s kind of a trap,” Banks said, since wildlife managers remove them whenever they find them.
Credit: Yusuke Fukuda
The findings suggest that targeting source populations for extra egg harvesting won’t be an easy way to stop the source of young crocodiles leaving home and moving to Darwin, simply because there are so many sources over such a wide area. “The current strategy of managing problem crocodiles when they arrive in Darwin, combined with an intensive public awareness campaign, will remain the most effective strategy for now,” Banks said.
The research did reveal some areas where the government could increase trapping efforts. Since half of the crocodiles came from rivers to the east of the city, “intercepting them closer to the eastern mouth of the harbor may be a strategy worth testing,” the authors concluded in the study.
Credit: Yusuke Fukuda
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.
