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.
Chronic wasting disease has been detectWhited in a wild deer in Indiana—the last Midwestern state believed to be free of the disease. The infected deer was discovered in early April as part of a state program that works with taxidermists to help in sampling efforts, Outdoor Life reports.
Indiana Department of Natural Resources officials say the deer was harvested in the 2023 season by a hunter in LaGrange County, near the border with Michigan, where the fatal prion disease had been detected previously.
“We had done prior intensive surveillance in that area,” IDNR deer program lead and biologist Joe Caudell told Outdoor Life. “This is one of those areas that we were always keeping an eye on. We wanted to make sure we had taxidermists participating there, and when we got sick deer calls from that area we were always on a little bit higher alert, because of that proximity to Michigan.”
The prion disease is always fatal to cervids, including deer, elk and moose. It has been detected in 34 states and four provinces.
As the climate changes, white-tailed deer are shifting northward into western Canada’s boreal forest. But what’s good for deer isn’t necessarily good for caribou.
“The expansion of white-tailed deer into the boreal forest has been linked to caribou declines,” said Melanie Dickie, a doctoral student with the University of British Columbia’s Okanagan’s Wildlife Restoration Ecology Lab.
In a study published in Global Change Biology, researchers looked at the northward movement of white-tailed deer (Odocoileus virginianus) as climate change creates milder winters and forestry and energy exploration create new food sources for deer. They found that the expansion is uprooting existing predator-prey dynamics, creating concerns for species like the threatened woodland caribou (Rangifer tarandus caribou).
The incursion of deer is accompanied by rising numbers of gray wolves (Canis lupus). The wolves also prey on caribou, which conservationists are trying to recover.
“Deer can handle high predation rates, but caribou cannot,” Dickie said.
The Wildlife Society recently recommended the Bureau of Land Management employ the best available science to minimize negative effects on wildlife from utility-scale solar energy developments.
Comments were developed in coordination with—and later co-signed by—a number of TWS sections and chapters, as well as TWS’ Renewable Energy Working Group. The comments highlight the importance of TWS’ Conservation Affairs Network in leveraging the expertise of TWS’ members in the organization’s federal policy engagement. Through this network, members from affected units and relevant working groups coordinated to establish the scope and framework of TWS’ comments to the BLM.
The BLM’s PEIS aims to update the 2012 Western Solar Plan, as mandated by Executive Order 14008 and the Energy Act of 2020. This legislative framework sets ambitious targets, including a goal of 25 gigawatts of electricity from wind, solar and geothermal projects on public lands by 2025. Originally covering six southwestern states—Arizona, California, Colorado, Nevada, New Mexico and Utah—the plan’s scope is now under consideration for expansion to also include Idaho, Montana, Oregon, Washington and Wyoming. This expansion reflects the evolving landscape of renewable energy development and emphasizes the need for comprehensive and local engagement to guide such endeavors.
In its comments, TWS emphasized the importance of using the best available data to inform siting decisions for utility-scale solar energy development. The PEIS as written, relies on existing resource management plans that are, in some cases, significantly out of date. By leveraging the most up-to-date scientific information and research findings, the BLM can make informed choices that minimize negative impacts on wildlife and its habitats while maximizing the efficacy of renewable energy projects.
Additionally, TWS recommended prioritizing the siting of utility-scale solar installations on previously disturbed lands and areas close to existing transmission infrastructure. This strategic approach not only minimizes further habitat destruction but also maximizes the efficiency of energy transmission, thereby reducing the overall ecological footprint of renewable energy projects.
TWS urged a holistic approach that considers the potential impacts on all wildlife, regardless of federal listing status. This included recommendations to consider the needs of species of greatest conservation need, at-risk wildlife, and birds of conservation concern. This approach would ensure that planning efforts are comprehensive and effective in safeguarding biodiversity and ecological resilience in the face of renewable energy development pressures.
Moreover, TWS emphasized the importance of recognizing and mitigating the indirect impacts of solar installations on wildlife behavior and migration patterns. Comments specifically recommended introducing a science-based buffer around exclusion areas in the PEIS to account for avoidance of and attraction to solar facilities on the landscape. By integrating design features that minimize disturbances and implementing adaptive management strategies, the BLM can mitigate long-term impacts on wildlife populations and their habitats.
Collaboration is central to The Wildlife Society’s advocacy efforts. Through the Conservation Affairs Network, participants emphasized the locally relevant impacts of the PEIS and provided crucial data and peer-reviewed literature to strengthen the final comments. The comments were co-signed by TWS’ Western and Southwest Sections, Montana, Nevada, New Mexico, Oregon, and Sacremento-Shasta Chapters, and Renewable Energy Working Group.
More and more biologists are turning to drones to survey wildlife on the landscape. By using thermal cameras, they can even find animals they might miss with the naked eye.
But a bird’s-eye view doesn’t mean the cameras will catch everything, and even thermal imagery has its downsides.
“There are trade-offs associated with each survey method,” said TWS member Aaron Foley, assistant professor for research with the East Foundation and the Caesar Kleberg Wildlife Research Institute.
In a study published in the Wildlife Society Bulletin, Foley and his colleagues evaluated the accuracy of daytime thermal-based drone surveys compared to helicopter, spotlight and trail camera surveys.
Helicopters and airplanes are the typical go-to vehicles for aerial surveys, but they can be dangerous for the crews and expensive for wildlife agencies. They can also be inaccurate and highly variable. In one study, Foley said, helicopter surveys detected anywhere from 20% to 70% of marked white-tailed deer (Odocoileus virginianus) on rangelands.
“We wanted to evaluate whether drones could generate more consistent population estimates,” he said.
Yet as drones emerge as an alternative, while studies around the world have looked at their feasibility, few have looked at their reliability.
That was a gap Foley’s team sought to address. Despite the advantages drones offer, their counts aren’t always accurate.
“There was a study from Australia that compared helicopter versus drone estimates of kangaroos,” Foley said. “The drone severely underestimated the kangaroo population size. If there was no independent population estimate via helicopter surveys, then one might erroneously conclude that the kangaroo population size was relatively low.”
To conduct their study, the researchers wanted specifically wanted to test the drone technology over a diversity of landscapes to see how well it performed in different terrains, areas with dense vegetation and open grasslands.
They tested the drones on five private, high-fenced ranches in South Texas, and surveyed a unique mix of native wildlife, domesticated animals and exotic species maintained for private hunts, from white-tailed deer to white-bearded wildebeest (Connochaetes taurinus mearnsi).
The researchers found a variety of factors that can influence the drones’ accuracy. Dense brush often blocked the view of animals on the ground. On one site, the drone was unable to follow the contours of the hills, resulting in a severe undercount in the brushy terrain. Even on flat grasslands, with little in the way to block the view, the reflectance of the sun on the landscape resulted in a hot background that made it hard for the thermal cameras to detect animals’ heat signatures.
But after accounting for visibility bias, the researchers found that the drones yielded population estimates for white-tailed deer similar to those from trail camera and helicopter surveys, and estimates from repeated drone surveys proved to be more consistent than those from helicopter surveys.
The findings suggest that drones can be reliable, the researchers found, but “some environments are more amenable to drone surveys compared to others.”
This article features research that was published in the Wildlife Society Bulletin, a TWS peer-reviewed, open-access journal. Join TWS now to access all TWS journals and read the latest in wildlife research.
Researchers are using 21st century technology to unveil traditional practices of fire stewardship.
Partnering with the Karuk Tribe, researchers from Oregon State University used a computer simulation model to understand how the Tribe historically used fire for ecosystem health.
Published in Ecological Applications, the findings show that before the arrival of European colonizers, cultural burning was extensive across the landscape, with an estimated 6,972 cultural ignitions occurring annually, averaging about 6.5 ignitions per year for each Indigenous fire steward.
The research focused on 1,000 square miles of Karuk Aboriginal Territory in the western Klamath Mountains of northern California. The mountains are part of a fire-prone ecosystem that historically had frequent fires of low or moderate severity but have recently experienced severe wildlfires.
Working with the Karuk Tribe Department of Natural Resources, OSU scientists developed historical estimates for cultural ignition locations, frequency and timing. Statistical parameters were collaboratively developed and honed with Tribal members and knowledge holders using interviews, historical and contemporary maps, ethnographies, recent ecological studies and generational knowledge.
“The information that went into this model is not new at all—it’s been held by Karuk Tribal members for millennia—but we developed new methods to bring the knowledge together and display it in a way that showcases the extent of Indigenous cultural stewardship across this landscape,” said Skye Greenler, who led the partnership when she was a graduate research fellow in the OSU College of Forestry. Read more from OSU
The ballot for The Wildlife Society’s 2024 elections includes nominees for the position of Canadian 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 Southwest Voting District includes all TWS members who reside in these geographic areas: Arizona, Costa Rica, Mexico, New Mexico, Texas
NOMINEES FOR SOUTHWEST REPRESENTATIVE TO TWS COUNCIL
Kathy Granillo
I have been active in The Wildlife Society for over 30 years, with most of that time spent in the Southwest. The wildlands, wildlife and wildlife professionals of this area are near and dear to my heart. I am the current Southwest Representative to Council (2021-2024) and I am seeking a second term. I believe I have accomplished much in my first term and that it has prepared me to do even more in a second term. I am actively involved in crafting the new Strategic Plan for TWS and want to help implement that plan over the next few years. I have helped shape the future of TWS through my work on the Diversity Committee, the Position Statements Committee, and as Council Liaison to the IDEA Working Group and the Climate Change and Wildlife Working Group. I strive to represent the Southwest geographic area by attending and presenting at the Texas Chapter annual conferences, and the Joint annual meetings of the Arizona and New Mexico Chapters. I sit in on chapter and section board meetings and stay in touch with members via the various newsletters and through email and phone calls. My priorities include focusing on better communication between scientists and managers; involving youth and minorities in conservation and science, and encouraging wildlife professionals to stay engaged and educated about our rapidly changing world and the impacts on wildlife and the places they live.
This is my first time running as a candidate for TWS SW Section Representative. I understand the workings of the Section fairly well by virtue of being your treasurer for the past few years and through my interactions with other board members. Truthfully, though, Kathy Granillo has much more experience with this position, and her long-standing support of the Section inspires me. I hope to learn from her until such time as she decides to leave the position. At that time, in addition to whatever the Section asks of me, I’d like to help the Section increase its support (logistical and financial) of international chapter members, for example by encouraging virtual and in-person attendance at regional and national meetings.
