Clark’s nutcrackers rarely forget a seed cache location. But many of the whitebark pines they depend on for food in Glacier National Park have disappeared, leaving the birds nearly a distant memory themselves.
“Glacier National Park is the epicenter of whitebark pine decline,” said Vladimir Kovalenko, a biologist with the U.S. Fish and Wildlife Service.
Whitebark pines have been suffering from a number of threats across their range, including climate change, wildfire and destruction by mountain pine beetles (Dendroctonus ponderosae). In Glacier National Park, white pine blister rust, a fungal pathogen that is also affecting the trees across their range, has hit particularly hard in recent years.
Kovalenko, who was a master’s student at the University of Montana at the time of this research, and his colleagues wanted to see how declines in these trees were affecting the population of Clark’s nutcrackers (Nucifraga columbiana) in the area. For a study published recently in Ecology and Evolution, the team compared nutcracker occupancy estimates to pine presence in different parts of the park.
Never forget
The Clark’s nutcrackers look unassuming—mostly gray with black and white wings. Their calls, similar to the screech of other corvids, cut through the forest. These birds have some of the most magnificent memories in the animal kingdom. They can hide pinecones in hundreds of unique caches, remembering where they put nearly all of them.
To estimate the population of the birds, the researchers used a combination of point count surveys and passive recording of nutcracker calls. They gathered data for three summers from 2020 to 2022 during the peak whitebark pinecone harvest season.
Whitebark pines are almost entirely reliant on nutcrackers to disperse their seeds. Credit: Vladimir Kovalenko
The team combined the data gathered from these two methods, and since these nutcrackers are rare in Glacier National Park, they used models to get a more accurate population estimate that takes the possibility of missed detections into account.
The researchers then compared the population estimates from the models to forest characteristics, including what types of trees were where. This analysis reinforced findings from previous research, such as the birds’ preference for dense whitebark pine copses.
“Clark’s nutcrackers were spending more time in areas with larger and more mature trees,” Kovalenko said.
Disappearing food source
Older whitebark pines produce more cones than younger, smaller trees. It usually takes over 50 years for these trees to begin producing cones, and upwards of 100 years to produce a particularly large crop of cones. As these old pines disappear, the nutcrackers may fly elsewhere, or switch to other food sources.
This lack of birds may also create a situation where whitebark pines themselves are unlikely to reproduce. Despite their sharp memories, Clark’s nutcrackers don’t remember every single cache. And they also sometimes die or leave the area before they can collect their hidden cones. As such, the birds act as seed dispersers for the trees. In turn, the whitebarks are almost completely reliant on nutcrackers for dispersal.
A whitebark pine cone. Credit: Vladimir Kovalenko
As mentioned in the cover feature of the March/April issue of The Wildlife Professional, if fewer trees means fewer birds, that also may mean fewer trees in the future. “There are fears that it’s going to produce this positive feedback loop,” Kovalenko said.
Kovalenko said this research reinforces the importance of conserving old growth whitebark pines. This kind of work might help retain Clark’s nutcrackers on the landscape, but other species like grizzly bears (Ursus arctos horribilis) also eat these pinecones. So what’s good for Clark’s nutcrackers is likely to be good for a host of other species.
Resident and transient killer whales often overlap in the Pacific off the West Coast of North America, but they don’t interact. Now, researchers believe the two aren’t just different populations. They’re different species.
In a study published in Royal Society Open Science, researchers determined they should be divided between resident killer whales (Orcinus ater) and Bigg’s killer whales (Orcinus rectipinnus), named for Michael Bigg, the Canadian scientist who first noted differences between the two in the 1970s.
The scientists found that resident killer whales travel in tight-knit family pods and eat smaller prey, like fish, and they have smaller skulls designed for that. Bigg’s killer whales travel in small groups and have larger skulls, allowing them to prey on seals and whales.
“They’re the most different killer whales in the world, and they live right next to each other and see each other all the time,” said Barbara Taylor, a former National Oceanic and Atmospheric Administration Fisheries marine mammal biologist who was part of the science panel that assessed the status of southern resident killer whales. “They just do not mix.”
Southern resident killer whales are listed as endangered.
The Taxonomy Committee of the Society of Marine Mammalogy is expected to decide if it will recognize the new species this summer.
Curly-tailed lizards are eating smaller anoles that play a key role in distributing resources from the ocean to the land.
As organisms that evolved in oceans over eons began to slowly move onto land, they took organic material with them. While researchers may understand this concept on a broad level, they have less information on the specific role species like lizards play in redistributing oceanic material to land. These materials are important sources of fertilizer for plants and connect land and marine ecosystems.
Oriol Lapiedra, a principal investigator with the Ecological and Forestry Applications Research Center (CREAF) in Spain, had been studying Cuban brown anole (Anolis sagrei) behavior for quite some time. While invasive in Florida, these lizards are native nearby in the Bahamas. They often eat small crustaceans found on seaweed that washes up on the beaches, as well as amphipods and isopods that eat the rotting vegetation. Northern curly-tailed lizards (Leiocephalus carinatus) also live in the Bahamas and prey on anoles.
Researchers introduced lizards to small islets in the Bahamas. Credit: Oriol Lapiedra
Anole populations are often in flux due to large tropical storms that blow entire populations of them off of small islets. Lapiedra has been interested in how the behavior of the surviving lizards might change with the presence or absence of predators.
Lapiedra observed that “on the islands with curly-tails, you don’t find [anoles] on the ground.” But he wanted to test this empirically.
On a series of eight islets off the coast of the larger Great Abaco Island in the Bahamas, Lapiedra and his colleagues experimentally reintroduced brown anoles in 2016, as detailed in a study published recently in Ecology Letters. The researchers implanted small identification tags about the size of a grain of rice under the skin of the anoles.
Oriol Lapiedra captures a lizard in the Bahamas. Credit: Oriol Lapiedra
A week later, the team released northern curly-tails on half of the islets—one for every 12 anoles, leaving the others as controls.
The team returned a year later to examine the anoles that were left on the island, as well as their offspring. After capturing the anoles, the researchers measured their body mass as well as the height of their perches. They also clipped a small portion of their tails to analyze the stable isotopes that would help determine the lizards’ diet.
The behavior of the persecuted
The team found that the diet of the anoles was different on islets with curly-tails compared to those without them. Ocean-based vegetation, like seaweed, has different carbon isotope signatures than land-based vegetation. The isotope analysis revealed that the anoles without the lizard predators ate more arthropods that fed on seaweed than the anoles that lived on islets with curly-tails.
Lapiedra said this is likely because the anoles don’t want to risk traveling far on the ground to exploit the seaweed on shore when curly-tails are around. While brown anoles are semi-arboreal, typically staying in plants a few feet above the ground, they often feed on arthropod prey they spot from above. With the curly-tails around, they tend to stay higher up in the plants, eating insects and spiders they find there. Lizards that do take the risk on the ground are quickly preyed upon.
“Curly-tails are extremely fast ground predators, but they can’t do anything on vegetation,” Lapiedra said.
The perch data correlated with this theory—anoles on the islets with predators were typically found higher up in the vegetation than the islets without them.
Northern curly-tailed lizards prey on anoles. Credits: Oriol Lapiedra
The body condition of anoles was generally poorer on islets with curly-tails as well. But some anoles still seemed to risk getting eaten to get to the resource-rich seaweed. Lapiedra’s analysis found that females that took the risk seemed to reap the rewards—they had better body conditions than those on the same islands that fed on prey higher up in the bushes and trees. Females may also be more vulnerable to predation as they lay eggs on the ground.
Lapiedra said that the difference in anole behavior on these two islands likely has a trickle-down effect on the ecosystems there.
The presence of curly-tails may benefit plants, for example. By keeping anoles in trees, they are forced to eat more arthropods that may feed on these plants. As a result, plants may grow faster without arthropods to eat them. At the same time, anoles on islands without curly-tails may transfer more marine-based resources by eating arthropods close to the shore and depositing them through their waste deeper inland.
TWS member Stacey Dauwalter always wanted to hunt, but she had a hard time setting aside the time to learn.
“Every year, I’ve been like, this is the year I’m going to put in the work,” said Dauwalter, the Wildlife Health Program Coordinator with the Idaho Department of Fish and Game.
The busy time in her lab coincided with hunting season, though, and those years kept coming and going. But when the Wild Sheep Foundation launched its program Women Hunt®, it was the perfect opportunity to put aside the excuses. In the fall of 2021, Dauwalter harvested her first white-tailed (Odocoileus virginianus) doe.
“I wanted to feel confident and have the skills to know that if I shoot routinely, I can stay on top of it,” Dauwalter said. “That’s what I wanted to get out of the course, and I got so much more than that.”
Women Hunt® is the brainchild of Renée Thornton, who, like Dauwalter, always wanted to hunt but didn’t know where to start. After hunting black bears (Ursus americanus) for the first time in her 40s, Thornton was hooked.
Part of the Women Hunt® instruction includes a culinary class, teaching participants how to prepare the meat they harvested. Credit: Women Hunt®
After meeting—and marrying—Gray Thornton, president and CEO of the Wild Sheep Foundation, Thornton left her corporate executive career, moved from Alberta to Montana, and started the organization’s Women Hunt® program.
Women Hunt® partnered with the FTW Ranch, a 14,000-acre West Texas ranch that already hosted a shooting school and had developed a new hunter course, since rebranded as Field to Fork. Women Hunt® worked to modify the program for 12 new women hunters to develop hunting skills and learn about the important roles that hunting can play in wildlife conservation and management.
“I look at what Renée does, and she absolutely changes lives for the better,” Gray Thornton said.
The Wild Sheep Foundation Women Hunt® 2024 application period is open May 1 to May 31.
A pair of little brown bats have been found infected with the deadly white-nose syndrome in Colorado. It is the second species in the state known to have contracted the fungal disease.
The state Wildlife Health Lab confirmed the disease after receiving a bat on March 5 that was collected by a wildlife rehabber in the town of Longmont. Two weeks later, a second little brown bat (Myotis lucifugus) was confirmed with the disease in nearby Boulder.
The fungus that causes white-nose syndrome was previously spotted in three little brown bat summer roosts in the state, but none of the bats had previously been confirmed as sick with the disease.
White-nose syndrome was first discovered in Colorado in March 2023 in a Yuma bat (M. yumanensis) collected by the National Park Service near La Junta. While the fungus has been found elsewhere in the state, these are the only three bats known to have contracted the disease.
Dan Neubaum, species conservation program manager for Colorado Parks and Wildlife, said the recent discovery was “unfortunate” but not surprising given the spread of the disease among bat species in other states.
Of the 19 bat species native to Colorado, at least 13 are believed to be susceptible to the disease.
White-nose syndrome was first documented in New York state in 2006. Since then, it has been confirmed in 12 North American bat species in 40 states and eight Canadian provinces.
When Edwin Jacobo was studying migratory birds for his graduate project in Southern California riparian forests, he spent most of his time trudging through cold water in the mountains. In April and March, he would pull on his old waders and set out at 5:30 in the morning to conduct point counts and mist netting for species like western tanagers (Piranga ludoviciana).
The waders were so old, they ended up with holes that patches couldn’t cover up. “I tried to fix them, but it just didn’t work,” said Jacobo, a PhD candidate at Washington State University who had just immigrated to the U.S. from Mexico at the time. Money was tight, and equipment was too expensive. “So I just decided to not use waders at all,” he said.
But the cold interfered with Jacobo’s ability to focus and conduct his research. “It was pretty miserable, to be honest,” he said. “I was shivering all the time.”
Just when things were getting unbearable, Jacobo’s advisor told him about the Trail Blazer Grant, a TWS program to help students and early-career professionals purchase professional gear to conduct fieldwork. He secured the funds and was able to purchase brand new waders.
Edwin Jacobo used the Trail Blazer Grant to help him purchase waders for a migrator bird project. Photo Courtesy: Edwin Jacobo
“There’s a big monetary barrier to becoming an established professional in this field, simply because you need gear to do specific training, and if you don’t get that training, then you aren’t qualified for a position,” said Amanda Veals Dutt.
The chair of The Wildlife Society’s Early Career Professionals Working Group, Veals Dutt helped develop the grant with the Student Development Working Group. “This is an easy way for our working groups and TWS as a whole to really help start to break down some of those barriers,” she said.
A personal endeavor
The idea and framework for the Trail Blazer Grant was conceived through the combined efforts of past Student Development Working Group officers but was finally brought online in 2023 by then past chair Darwin Mayhew. Although the pandemic’s impact on the working group prevented Mayhew from being able to do as much as he wanted with the working group when he took over as chair in 2022, the framework of the Trail Blazer grant that had been handed down to him reminded him of his own challenges.
Starting a career in wildlife biology, Mayhew faced learning differences, but soon discovered that growing up “without much money” created a new set of obstacle for getting into the wildlife field.
“I grew up, myself, without having very much money and I didn’t want people prevented from fieldwork because of any limitation, visible or inviable,” he said.
Typically, students and early-career professionals get the research tools they need from their lab or employer, like camera traps or radio collars. But what about the basics, like boots, binoculars and backpacks? For biologists just starting out, basic gear can be out of their price range.
“Early-career professionals represent about a third of The Wildlife Society’s members, but I think we’re actually probably one of the most underserved groups, simply because we kind of get forgotten since we’re no longer students,” Veals Dutt said. “We no longer have a lot of student-specific travel grants or scholarships. And we are not established professionals. We don’t necessarily have multiple years in a position and solid financial status built up.”
Since it went live in 2023, the Early Career Professionals Working Group has supplied $500 for two $250 grants for early career professionals and students. The Student Development Working Group contributes $1,000 for two $250 grants for students and five $100 grants also for students. The outdoor company Vortex also donated five binoculars for the first year of the grant.
Interested in becoming a sponsor? TWS is seeking tax-deductible monetary and in-kind donations of gear. You may email TWS’ development manager Lauren Ruotolo at LRuotolo@wildlife.org for more info.
While the idea was solid, the working groups had to think about who qualified for the grant and how to choose recipients. They wanted everyone who was underrepresented to have access, but that proved challenging. The first year, the grant ended up being open only to TWS members who were part of either the SDWG or ECPWG, but this left some members—like those on six-month trial memberships, which are often utilized by the neediest students and early career professionals—falling through the cracks. As the grant evolved, it became available to all members, with priority given to those we are also members of one of the working groups.
Isa Mattioli purchased the funds to purchase spotting scopes, a field bag and a headlamp with the help of the Trail Blazer Grant to help complete their surveys for Pismo clams. Photo Courtesy: Isa Mattiolio
Choosing who received the funds was another challenge. How do you compare one person’s hardship to another’s? As a result, they decided to make it a lottery system. If recipients had some level of need, they all had the same chance of getting the funds, although they set aside specific slots to go to early career professionals, who have had less than 36 consecutive months of full-time, non-entry level employment.
The Wildlife Society and others have shared information about applying to the grant on social media to make people aware.
The ease of application helps, some recipients said. “I think that one of my motivating factors in applying was I looked at the page and was like, ‘oh, I could literally do this right now,’” said TWS member Isa Mattioli, an undergraduate student at Cal Poly, San Luis Obispo, who received the grant. “The reimbursement process was really easy. It really helped me buy field gear that was really important to starting my senior research project.”
Funding the future
Mattioli, who uses they/them pronouns, used the funds to purchase spotting scopes, a field bag and a headlamp to help complete their surveys for Pismo clams (Tivela stultorum) on California’s Central Coast, where sea otters (Enhydra lutris) prey on the clams. “I think that this grant really helps to attempt to level the playing field and gives people in underrepresented groups less of a worry about finances,” they said.
Kelsey Shepherd, a graduate research assistant at Iowa State University, also benefited from the grant. Not only did the grant help her purchase waterproof boots to help her get through rugged terrain in tallgrass prairie to study the federally endangered rusty patched bumblebee (Bombus affinis). She was also able to buy special sunglasses that she needs. “I have a genetic condition, and I’m blind in one eye,” she said. “I was able to protect my eyes from the sun.”
The chair-elect of the Student Development Working Group, Laura Young, has now taken on keeping the grant going. She hopes to improve the grant so that more people can take advantage of it at the right time during field season. “We are looking at potentially doing multiple deadline rounds because of different field seasons,” she said. “Some people don’t necessarily know what field gear they need until they’re hired for something. The deadline selection process may have already passed before they get hired.”
The working groups also hope to get even more applicants. “We had a pool of 77 applicants across our two working groups for the 2023 grant,” Veals Dutt said. “My hope is that we can get more folks to apply and just have this be a really solid continuing grant that we can offer.”
Is affording the right field gear a struggle? You may qualify for the Trail Blazer Grant provided by the Student Development and Early Career Professional working groups! Applications are open now through April 30.
Biologists are concerned about the impacts of avian influenza on seals and sea lions. The virus, which has devastated wild bird populations and poultry operations around the world, but has also affected a variety of mammal species. That includes pinnipeds, which have died from the virus in various places across the globe.
Over 300 seals died from the disease in New England, several more died in Puget Sound in Washington, over 20,000 sea lions have died and Chile and Peru and thousands of elephant seals have died in Argentina, according to the Associated Press.
Scientists believe the mammals are likely contracting the virus from affected seabirds.
“The loss of wildlife at the current scale presents an unprecedented risk of wildlife population collapse, creating an ecological crisis,” the World Organisation for Animal Health said in a statement.
It was June 2021, and researchers were trying to capture a pueo to fit it with a GPS tracking device as part of a larger effort to learn more about the owls’ movements around Hawaii.
They set up a net trap with a decoy owl during mating season and used a speaker to play the squeaks of a male pueo. The charade worked, and another adult female pueo was soon lured into the net, likely in an effort to lunge at the potential invader.
“The pueo heard the call, came, saw the fake owl, and ‘Vroom!’ attacked the fake owl,” said Marie-Sophie Garcia-Heras, who was working as a postdoctoral researcher studying the owls at the time with The Pueo Project, a program led by Melissa Price at the University of Hawaii at Manoa.
The remains of a dead stilt chick were dropped in a net trap by a pueo. Credit: Garcia-Heras et al.
Only the trap didn’t work—a gust of wind made the net collapse just as the female was flying in. The bird escaped, much to the consternation of Garcia-Heras and her colleagues. They went to fix the trap, and to their surprise, they found the still-warm body of a dead ae’o chick, also known as a Hawaiian stilt, laying on the ground at the bottom of the net. The owl must have just captured the prey, then dropped it during the bungled capture.
Pueo project researchers weren’t entirely shocked by this finding. As described in a research note published recently in Ecology and Evolution, the researchers had witnessed a few similar cases since 2019 of pueo preying on Hawaiian stilts. It just wasn’t until now that they had cold evidence—a warm body—in their hands.
Researcher Marie-Sophie Garcia-Heras holds a pueo. Credit: Melissa Price
A tale of two endangered birds
The U.S. Fish and Wildlife Service lists Hawaiian stilts as endangered. The shorebirds have drastically declined due to decades of habitat loss and fragmentation. Invasive species like feral cats (Felis catus), dogs (Canis familiaris) and mongoose (Herpestes edwardsii) also prey on Hawaiian stilts.
Pueo, also known as Hawaiian short-eared owls (Asio flammeus sandwichensis), are a subspecies of short-eared owls (Asio flammeus) endemic to Hawaii. These owls are a little more generalist than their mainland U.S. counterparts, which mostly stick to grasslands. In Hawaii, pueo can occupy wetlands and forested areas as well as grasslands. These birds are also threatened by habitat loss and fragmentation, especially on Oahu, where the state of Hawaii lists them as endangered. Researchers don’t have numbers, but they suspect populations have dropped as human activity has increased in Oahu.
In ongoing research, scientists are trying to determine whether the numbers in Oahu are really dropping or whether these birds are just migrating between the islands of the archipelago—Garcia-Heras said they have been tracked flying between islands.
The remains of stilts found in the area where pueo nested. Credit: Garcia-Heras et al.
Mounting evidence
It was in the midst of their Hawaiian stilt research that scientists first saw evidence that these owls may be preying on the shorebirds. They had set up a trail camera up near a stilt nest on Oahu—the birds typically lay their eggs on round bits of mud they form on the ground.
In 2019, the cameras captured footage of pueo activity around a nest at night. The trouble was that they couldn’t tell for sure whether the raptor had taken a chick from the footage. But the adults were absent—perhaps having fled the pueo to save their own skin.
In 2020, researchers conducting nest surveys of stilts witnessed a pueo chasing adult stilts around. While they didn’t see the outcome, they later flushed a pueo from a ground roost that contained long stilt leg bones. Garcia-Heras said the researchers also “found that stilts were very anxious when pueo were around.”
In June and July 2021, in the weeks following the event where the researchers were left with a freshly killed stilt chick in their net, researchers discovered the carcasses of 10 adult ae’o strewn about an area near where a family of five pueo had been observed. These carcasses were picked clean, leaving mostly wings and bones. Garcia-Heras said these kinds of remains are typical from raptor feedings rather than other kinds of carnivores, which might have chewed the bones more.
Hawaiian stilts, or ae’o, are endemic to Hawaii. Credit: Melissa Price
Pueo are the only raptors on Oahu other than invasive barn owls (Tyto alba). The latter typically prey on small mammals, though, Garcia-Heras said, and all the other circumstantial evidence points to the nearby pueo family.
While stilts are taller than pueo, the ae’o are all legs—pueo typically weigh about 290-340 grams versus the stilts’ 180 grams.
“The timing, the location just very much correspond to a pueo predation event,” Garcia-Heras said.
Given the conservation status of the pueo, many management actions, like removing the pueo, aren’t plausible. Plus, Garcia-Heras said that pueo have a high importance in Hawaiian culture as protective guardians.
Both of these birds are native and endemic to the islands, so predation is likely natural between the species. But researchers hadn’t previously considered pueo predation as a potential factor affecting stilt numbers.
“It could be a problem if there’s one bird that starts hitting the Hawaiian stilt population,” Garcia-Heras said.
A program in Alberta is helping the province manage its wild pig population. The Alberta Invasive Species Council says reported pig sightings have doubled over the three years of its Squeal on Pigs campaign. After receiving reports of wild pigs (Sus scrofa) from the public, trappers are dispatched to remove them. Since the program began in 2021, 314 pigs have been removed. Officials don’t know how many wild pigs are in the province, but a University of Alberta effort is deploying trail cameras to try to get an estimate.
The number of wild horses and burros on public land has declined at its sharpest rate since 1985, marking the third year since 2020 that the overpopulation has decreased.
A March 1 report from the Bureau of Land Management estimated about 73,520 federally protected wild horses and burros roamed on BLM lands—9,363 fewer than was estimated in 2023. The estimate includes a range of uncertainty between 63,432 and 85,249 animals.
BLM officials say they can’t pinpoint the causes of the reduction, but the agency has been working to reduce the numbers. In the past year, the BLM removed 11,784 animals from overpopulated herds and offered them for adoption. The BLM has also worked to increase the use of fertility control vaccines. Deep snows throughout much of the West may have also reduced herds or dispersed some animals.
Despite the reduction, BLM officials say the population remains nearly three times what scientists estimate the lands can support. Its current plan calls for removing 20,000 wild horses and burros and treating 1,400 horses with fertility control in Fiscal Year 2024.
For TWS’ position statement on feral horses and burros, click here.
