JWM: Humans main factor in Spanish Bonelli’s eagle decline

Electrocution, poisoning, shooting and even drowning have led to an alarming death rate of Bonelli’s eagles in eastern Spain.

Recent findings on the state of these raptors have led researchers to call for further conservation action to protect the birds and their ecosystems.

“The whole population has been declining for several years,” said Andrés López-Peinado, a PhD student studying biodiversity at the University of Valencia.

Bonelli’s eagles (Aquila fasciata) live in coastal areas of the Mediterranean as well as in patchy areas in Asia, from the Arabian Peninsula to Indonesia. In some areas, populations are stable, but in Spain, researchers suspected an unsustainable death rate may be causing declines.

In a study published recently in the Journal of Wildlife Management, López-Peinado and his colleagues analyzed data from 60 Bonelli’s eagles fitted with GPS devices attached by backpack harnesses from 2015 to 2023 in northern Valencia and in neighboring Castilla-La Mancha.

Why are Bonelli’s eagles declining?

Some 33 of these birds died during the research period. The researchers detected deaths through a lack of movement on the GPS devices and brought the carcasses to veterinarians for necropsies. The results of these tests revealed that two-thirds of the dead birds died from anthropogenic causes, while about 27% died from natural causes—all but one, which succumbed to disease, died from predation. The final 6%—two birds—died of unknown causes.

Of the birds that died from human causes, the main reason was electrocution on power lines—a problem that has been found to affect raptors in many parts of the world, from Mongolia to the United States. Among the birds these researchers studied, about 18% died from electrocution, while about 9% died from collisions with power lines.

Poisoning was a close second at 15% of the eagles that died. López-Peinado and his colleagues said that these instances were likely intentional, as was the case for the 9% of eagles that were shot. Pigeon fanciers—people who breed and care for pigeons—will sometimes use bait pigeons with carbofurans—a pesticide banned in the U.S. and many parts of Europe—smeared on their plumage to remove eagles they perceive as a threat from the area. When eagles prey on the pigeons, they become poisoned. All three shootings occurred outside of the hunting season for other birds, during a time when firearms weren’t allowed in the area.

“Intentional persecution of Bonelli’s eagles and raptors, in general, is far from being eradicated in eastern Spain,” the authors wrote in the study.

Bonelli’s eagle have a large distribution, including in India, as this bird pictured. Credit: Birds of Gilgit-Baltistan

Will Bonelli’s eagles go extinct in parts of Spain?

The researchers calculated what this level of deaths means for the population in this area. They found that if mortality continues at this rate, there is a 99.2% chance that the birds will be extirpated from the area in the next 100 years.

“The risk of losing that small population—if we are not depending on immigrants—is almost 100%,” López-Peinado said. As a result of this research, the province of Valencia has listed the eagle as endangered. In the rest of Spain, it’s listed as vulnerable. In fact, he said that the population in the southeast of Spain is the only one that is still doing OK.

Luckily for the Valencia area, immigrants from other populations come in, but the problem remains for Bonelli’s eagles in the larger region.

López-Peinado said that part of the problem is that a lot of the deaths are occurring during the breeding season, which can stop the growth of future generations.

While most people think that this species does better in coastal areas, this wasn’t necessarily the case in terms of deaths. Along the Mediterranean, more eagles died from human causes, while in the interior, more birds died from natural causes.

Another problem is a lack of protected areas, López-Peinado said. Most of the deaths—particularly the human-caused ones—occurred outside of protected areas. The trouble is the protected areas aren’t big enough for these wide-ranging raptors, López-Peinado said, and some of those that exist aren’t well managed ecologically.

How can we save Bonelli’s eagles?

To address this problem, he and his colleagues are currently speaking with the administration of protected areas to implement management. Some improvements that might help the eagles include opening up the forest canopy to give them more areas to hunt, for example.

Other potential measures that might benefit the species include retrofitting power lines to make electrocution less likely. Since three birds in the study died due to drowning in water tanks—they go in for water and have no way to get out—López-Peinado said that building ramps or fencing these water sources off better might also help reduce the deaths from human causes.

“We are losing habitat and increasing the anthropogenic causes of death,” he said. “If we want to reduce this problem, we have to focus on getting a better area for them and reducing the deaths.”

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.  

Judge grants USFWS 3 more years to decide on hippo status

Federal authorities have three more years to decide whether to list the common hippopotamus as endangered or threatened after a recent court decision. While not native to the U.S., several conservation groups petitioned the USFWS to add the common hippopotamus (Hippopotamus amphibius) to the U.S. Endangered Species Act in 2022 due to the trade of its parts in the U.S. for meat, leather and other products. As a result of poaching in Africa and other issues, the hippos are declining in many parts of their historical range. A federal judge has now ordered the USFWS to decide about listing hippos by July 27, 2028.

Read more at USA Today.

A love letter to The Western Section

I will preface this letter by saying it is truly intended for all of our Sections, Chapters, Student Chapters, Working Groups and Communities. Your work to provide year-round member support and community at the local level is essential to the overall well-being of our members and the profession. However, I just returned from the Western Section’s meeting in Visalia, California, so the Section is fresh on my mind and in my heart. Wishing you all a Happy Valentine’s Day.  

Dear Western Section of The Wildlife Society,

I hope this letter finds you amid a glorious day in nature amongst the beautiful landscapes that you call home. My admiration and affection for all that you and your members do know no bounds, but I write today to express my gratitude for the enlightenment you have bestowed upon me over three short days.

Last week, I didn’t know what to expect as I traversed the country for your meeting. I have traveled to many organization unit meetings before, but this was the first time I had visited with a Section since COVID. I worried about how things might have changed between us. I wondered if it would still feel the same as I remembered. After all, much has changed in the past five years.

As I walked through the convention center doors, I knew something felt different. At first, I struggled to identify the feeling. The event looked the same. The exhibit hall was bustling with traffic, and the members greeted each other with smiles. By all accounts, this was a well-organized, well-attended and well-liked meeting.

The theme of the Western Section’s annual meeting was “a return to natural history.” Credit: Cameron Kovach

Then, I realized something—it wasn’t you; it was me. I had changed. I was nervous. Before COVID, I had unbridled confidence to enter an unfamiliar room with an unfamiliar crowd, bolstered by a strong (but ultimately false) sense of self-worth. Despite my best efforts, I couldn’t summon the confidence that once came so easily. What had changed?

Two years of isolation followed by a few more years of remote work certainly zapped me of some social skills, but this felt much deeper. Without regular external engagement, I was left with years of self-reflection. I developed a deeper sense of my values but also a distinct awareness of my flaws and past failures. During this time, I also experienced the profound sense of humility that comes from starting a family, including seeing beyond my ego, accepting imperfection and discovering the full spectrum of daily emotions that accompany watching your children grow. Having my priorities and perspectives shifted meant that my ability to perform was now gone.

With my false bravado stripped, I was left feeling exposed. Though I didn’t expect this, the palpable passion and dedication of your members lifted me to a place of genuine self-worth. I was moved by the kindness and openness of everyone present, and though at times I could sense disagreements, those disagreements never turned to conflict. Your members engaged with authenticity, communicated with respect and rallied around the shared values that united us all.

I left Visalia, moved by what I had experienced. I no longer felt burdened by the weight of external validation but free to embrace my true self and be accepted for it. In the words of your Capstone presenter, Earyn McGee, I felt “brave enough to believe that we have the power to create a better world.” Your work is a testament to the power of collective action and the difference that a group of committed individuals can make.

Please know that your efforts do not go unnoticed. I know I am not alone and that the impact of your work and the community you create is felt far and wide. Thank you for welcoming me. Thank you for inspiring me. Thank you for always moving us forward.

With heartfelt gratitude and admiration,

Cameron Kovach

How to improve invasive python removal

Wildlife professionals and Florida residents have been working hard to remove invasive Burmese pythons that compete with native wildlife for food and habitat. But researchers recently uncovered some ways to make surveys and removals of the snakes more efficient. In a study published in Scientific Reports, scientists compiled data that Burmese python (Python bivittatus) contractors to reveal some patterns. They found that python removals could likely be increased in two regions: the western edge of Big Cypress National Preserve and a stormwater treatment area in Palm Beach County. They also found that surveys were more successful from May to October and that a drop in barometric pressure the previous day increases the success of surveys. In addition, survey periods between 8 p.m. and 2 a.m. worked best, and boats helped with survey effectiveness. “Pythons disrupt food webs, altering predator-prey dynamics and reducing populations of key native species. By refining removal strategies, we’re working to give native wildlife a chance to adapt and persist,” said Alex Romer, a quantitative ecologist at the University of Florida, Institute of Food and Agricultural Science’s Fort Lauderdale Research and Education Center and corresponding author on the paper.

Read the study in Scientific Reports.

TWS2024: Environmental DNA reveals bat roosts under bridges

Environmental DNA analysis can reveal evidence of threatened and endangered bats roosting under bridges—an important tool to ensure contractors take proper conservation measures before construction or renovation.

Bridges require maintenance, including renovations and construction, to keep them safe for vehicles. But this type of work could disturb—or even kill—bats whose presence is difficult to detect.

“In human-modified landscapes, bats often lack suitable roosting habitat, so they will occasionally roost in bridges,” said TWS member Daniel Fisher, a PhD candidate in ecology and evolution at Rutgers University in New Jersey. Some bridges host maternity colonies where mothers raise their young, he added. “Any fatality to a maternity colony is going to have a real impact on population growth.”

If contractors know bats are using the bridge, they could delay their work until the roosting season or create an exclusion device that keeps the bat away after they leave to forage for the night. Workers can only do the latter if there are no flightless pups present.

But to take these measures, wildlife managers need to know where the roosts are. In ongoing work Fisher presented at the 2024 TWS Annual Conference in Baltimore, Maryland, he and his colleagues tested if environmental DNA might reveal the presence of bats that may otherwise be undetectable around bridges. Bats shed DNA, such as urine, guano or other traces, in areas where they roost, offering prime samples for eDNA detection.

Bats use various features of bridges to roost. Credit: MacKenzie Hall/NJDEP

Under the bridge

To conduct the study, Fisher and his colleagues tested 14 bridges known to host bat colonies around New Jersey. They swabbed surfaces of different bridge features using clean paint rollers. Some of these features included abutments, which are the structures at either side of the bridge; embankments, or the slopes leading up to the abutments; expansion joints, or gaps built into the structure of the bridge to help bridges from buckling due to normal contractions and expansions from temperature changes; support beams that run under the bridge parallel to the way cars drive; and bents, which are the columns that support some bridges. For each of the 14 bridges, the team chose three of these features, swabbing them twice each in the summer of 2022, in the winter of 2022-2023 and in the spring of 2023.

They found that the easiest season to detect bats was the summer when roosting colonies are active. But they could also find evidence of bats in the other seasons sometimes—just not as reliably.

The bents, the expansion joints and the embankments were most likely to retain traces of bat DNA, though the latter was a lot less reliable than the other two.

“If you want to conduct an eDNA survey on bridges for bats, you should sample bents and expansion joints in the summer for the highest likelihood of detection,” Fisher said.

Researchers used paint rollers to gather environmental DNA samples from various features underneath bridges. Credit: Morgan Mark/Rutgers University

In most cases, the eDNA analysis revealed the presence of the species that researchers already knew lived under the tested bridges, but there were a few surprises.

For example, the survey revealed the presence of a northern long-eared bat (Myotis septentrionalis), a species the U.S. Fish and Wildlife Service lists as federally endangered.

At another four bridges, the researchers detected traces of eastern red bats (Lasiurus borealis), which surprised the researchers because this species usually roosts in foliage and only occasionally in human-made structures. Fisher said the researchers aren’t sure whether these red bats were actually roosting at the bridges or that there were just high levels of red bat activity in the area.

Overall, Fisher said that knowing more about how bats use bridges and how scientists can detect them is important for wildlife managers trying to minimize harm to the creatures.

INTERPOL seizes 20,000 trafficked animals 

INTERPOL has led an operation seizing 20,000 protected or endangered animals in a global wildlife trafficking sting. Criminal networks were smuggling the live animals across borders to sell for uses such as specialty food and traditional medicine. Led by INTERPOL and the World Customs Organization (WCO), the multinational campaign known as Operation Thunder 2024 involved enforcement agencies from 138 countries and regions and led to the arrest of 365 suspects. Officials also identified six transnational criminal networks suspected of trafficking animals and plants protected by the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). In addition to live animals, authorities confiscated hundreds of thousands of animal parts and derivatives from protected species. Officials transported rescued animals to conservation centers where they await repatriation, rehabilitation or necessary treatment.

Read more at INTERPOL.

How well does JWM perform on gender equity?

The equity gap between men and women persists in many realms of the wildlife profession. But recent data has revealed that more women are publishing peer-reviewed studies in the Journal of Wildlife Management.

“We generally found that the number of women authors has increased over time, which is great,” said TWS member Rebeca Becdach, a master’s student at the California Polytechnic State University, Humboldt. “But we’re still not where we want to be.”

Becdach and her supervisor at the university, TWS member and biologist Ho Yi Wan, have been interested in exploring ways to increase access and participation in the wildlife profession for underrepresented individuals.

Wan was curious about how the gender gap might be represented in the publication history of the Journal of Wildlife Management (JWM), one of The Wildlife Society’s journals. He worked with an undergraduate student, Kellie Crouch, to compile data on all the authors of studies published in the journal from 1999 to 2020. The team then ran these names through genderize.io, an online program that determines the likely gender of a first name as well as the percentage of accuracy.

Becdach and her colleagues published a review recently in the Journal of Wildlife Management, where they analyzed the data that Crouch began working on to determine what the journal’s gender skew was and how it has changed over time.

To avoid misattributing genders to names, they only counted author names that the program classified with a certainty of 80% or more.

Becdach presents a poster at The Wildlife Society’s Western Section annual meeting in Riverside, California on her research on gender in the Journal of Wildlife Management. Credit: Lila Bowen

How has gender representation changed?

The analysis revealed that 25 years ago, the gender of published authors was skewed a lot more toward men. There were only about 14 women for every 100 men as first authors and about 12 women for every 100 men as co-authors.

However, this vastly changed over the years. From 2015 to 2020, there were about 60 women for every 100 men listed as first authors and about 30 women for every 100 men listed as co-authors.

“Since the early 2000s, we’ve definitely made improvements,” Becdach said. But she added that the number has pretty much plateaued, not improving much over the last half decade of the study.

The researchers also analyzed the affiliations of the authors. They found that the number of women authors from all kinds of institutions increased, whether governmental, academic, nonprofit or private consultancies.

Becdach and her colleagues also saw an increase in women authors publishing on all taxa of wildlife studied in JWM by the end of the study compared to 1999. In fact, when it came to studies on amphibians or invertebrates, more women were first authors than men in the latter half of the study period. But Becdach noted that this might just be due to a small sample size, at least with invertebrates—there were only 13 authors studying invertebrates compared to the thousands of authors they analyzed overall.

Becdach credits groups like TWS’ Women of Wildlife Community and efforts to include more women in TWS conferences and get women involved more generally in the profession as reasons why the gender skew has improved over the years. Having plenty of women mentors can also help younger women get into the profession, Becdach said.

But women also continue to face barriers. “There are unconscious biases when hiring women,” Becdach said. Other problems may relate to the ways that women are raised in society—their families may not introduce them to wildlife, the outdoors and natural resources as much as men. There are also societal expectations based on gender and caretaking responsibilities often fall to women.

In addition, men hold many of the higher positions in the profession. This may take longer to change because people in these positions tend to stick around for longer periods of time. The positive side of this, Becdach said, is that many women hold positions that could eventually lead to higher ones.  

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.  

Planned underpasses will help boost red wolf recovery

Federal grants and private donations will help fund a series of wildlife underpasses in one of the two places where red wolves exist in the wild. The money will be used to revamp about 2.5 miles of the busy, two-lane U.S. 64 in North Carolina’s Alligator River National Wildlife Refuge with underpasses and fencing to shepherd red wolves (Canis rufus) and other wildlife safely underneath traffic. While the exact number and size of the underpasses have yet to be determined, the estimated cost for the project is around $31.5 million, including $4 million in private donations. The Federal Highway Administration’s Wildlife Crossings Pilot Program also contributed grant money to the project. “This is one of the most important wildlife connectivity projects in the country,” said Beth Pratt, founder of the nonprofit The Wildlife Crossing Fund, which raised funds for the project. There are less than 20 red wolves estimated to live in the wild. “Critically endangered red wolves will disappear if we do nothing.”

Read more at the Associated Press.

WSB: Breeding wolves vulnerable to wolf harvest

The legal wolf harvest in Idaho disproportionately affects breeding individuals—males and females that lead packs—during the breeding season.

Previous research reveals that removing these individuals from packs can hinder population growth.

“Those breeders are more vulnerable during the breeding season—they have breeding on the mind,” said Peter Rebholz, a research biologist at the University of Idaho.

In a study published recently in Wildlife Society Bulletin, Rebholz and his colleagues identified breeders from tissue samples from wolves harvested in Idaho. Then, they determined what proportion of the harvested wolves were breeders and what season they were harvested in.

Researcher Peter Rebholz at an active wolf den. Credit: The Gray Wolf Research Group

Using genetic analysis, the researchers could identify breeders when they could compare the genes from tissue samples from parents—gray wolf (Canis lupus) packs typically only have one breeding couple—and direct descendants.

They found that breeding wolves were disproportionately harvested in January and February—their breeding season.

This may be due to breeders often being the first to investigate scent lures or predator calls. “Breeders [are] the first in a fight—the first to defend the territory—and in the breeding season, they are even more ramped up,” Rebholz said.

He said that wildlife managers can use this information to adjust or remove seasonal hunting regulations, depending on whether the goal is to have more or fewer wolves on the landscape.

It’s also possible that removing these breeders has other effects on pack behavior. Pack leaders usually guide hunts and know their territory better than other individuals.

Rebholz works in the lab. Credit: The Gray Wolf Research Group

Removing the breeders could cause packs to break up, and the movements of individuals may become more erratic for a period of time, as individuals set out to form new packs or join other preexisting ones.

“The longer a breeding pair is together, the more successful that pack tends to be in terms of hunting, raising young, and, a lot of times, staying out of the way of humans,” Rebholz 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.  

Headstarting program gives endangered amphibians, reptiles a boost

A national nonprofit is leading the charge in one of the largest amphibian and reptile headstarting efforts in the U.S. The Amphibian and Reptile Conservancy (ARC) began the effort earlier this year to help conserve a number of species, many of which are close to extinction. “Headstarting isn’t a new technique, but ARC is taking it to an entirely new level,” said the organization’s executive director, JJ Apodaca. “In the most comprehensive effort of its kind, we’re targeting multiple critically imperiled species simultaneously while also tackling the root causes of their declines.” The organization will be raising in captivity species, including the federally threatened bog turtle (Glyptemys muhlenbergii), federally threatened Chiricahua leopard frog (Lithobates chiricahuensis), federally endangered Houston toad (Bufo houstonensis) and others. Then, they will release them back into the wild to bolster populations.

Read more from ARC.