Drones reveal grebes’ nesting activity

October 27, 2020 by Joshua Rapp Learn

Forget about sneaking up on a flock of western grebes. In the Cascade reservoir in western Idaho, the birds sometimes nest on floating patches of vegetation. If they don’t take flight immediately when a biologist starts slogging through the wetlands towards them, the agile swimmers will dive deep under water.

“The species is really sensitive to human interactions,” said Deo Lachman, a biologist with the U.S. Fish and Wildlife Service.

Western grebes (Aechmophorus occidentalis) have declined by about 90% between 1970 and 2017, and researchers don’t completely understand why. As a master’s student at the University of Idaho, Lachman and his colleagues wondered if their breeding and nesting strategies could offer any clues about the decline.

But getting close enough to the birds to count eggs and chicks wasn’t easy. With a little brainstorming, the researchers came up with a new strategy that could help them learn more from a distance, keeping the water birds comfortable in turn.

Deo Lachman with a drone. Credit: Diane Evens Mack

In a new study published in Wetlands Ecology and Management, he and his colleagues describe using quadcopter drones provided by the U.S. Geological Survey to give them a bird’s eye view of the grebes at Lake Cascade, Deer Flat National Wildlife Refuge and Minidoka National Wildlife Refuge.

“The drones worked out really well,” he said. The researchers managed to identify a record number of grebe nests — including the largest colony of western grebes, with about 1,053 nests.

Multiple drone flights at about 150 feet above ground allowed them to create maps of the colony over time, including when nests were built, when eggs were laid and how many were lost over time to things like predators.

The flights also told them more about water depth around their nests and how close the grebes typically nested to their neighbors. Initial research showed that water depth at the beginning of the breeding period and how water changes throughout that period is pretty critical for nest survival, Lachman said.

While they haven’t yet nailed down the cause of the western grebes’ decline, Lachman speculates that it might be tied to habitat lost, which can be exacerbated by surrounding agriculture and climate change, both of which draw down the water levels in the wetlands where the birds nest. Lachman said there also might be an ecological trap occurring in which areas that look like suitable nesting habitat early in the season may become too shallow or dry later on the season when the eggs hatch due to water withdrawals from farming.

Western grebes are highly adapted to an aquatic lifestyle, using water both for foraging and courtship. Their elaborate courtship rituals involve copycat motions and a coordinated bout in which both partners literally walk on water in tandem.

The grebes typically attach their nests, made of wads of vegetation, to bulrushes or other plants sticking out of the water, though their nests are sometimes free-floating. The drones revealed that grebe nests survived better in deeper water.

A drone image showing grebes in their environment. Credit: Deo Lachman

The birds’ nest location choices are partly due to their physiology. Their body shape, streamlined for swimming in pursuit of prey underwater, makes them ill-suited for walking on land. Their chicks typically take refuge on the backs of the adults after hatching and stay there until fledging, making it important for the adults to nest above water — waddling with chicks on their backs makes them and their offspring a lot more vulnerable to predators.

“They’re horribly awkward on land — they can’t maneuver very well,” Lachman said. “It poses quite the predicament for the young.”

As climate change contributes to drier conditions, the water table decreases, leaving the grebes with less optimal nesting habitat. Farmers also draw more from waterways during increasingly dry conditions, which may exacerbate the water problem, Lachman said.

Monarchs, bees use cultivated milkweeds as much as wild ones

October 27, 2020 by Dana Kobilinsky

Monarch butterflies and bee species use ornamental milkweed plants — the kind sold at garden centers — just as much as they use native plants, researchers found.

“There’s a ‘native-plant’ movement going on right now,” said Adam Baker, a researcher at the University of Kentucky College of Agriculture, Food and Environment and lead author of the study published in PeerJ. “We wanted to look a bit deeper into that, especially the use of cultivated native host plants in conservation gardens.”

Baker knew that cultivars — natural variants of native plants crossbred or hybridized with ornamentals for their appearance and disease resistance — can provide nectar and pollen at times where wild plants lapses.

He and his colleagues wondered how well monarch butterflies (Danaus plexippus) and bees benefited from them. They specifically wondered if the insects would choose the cultivars at the same rate that they would choose wild species, whether for laying eggs, for a food source or for defensive reasons.

He and his colleagues wondered if monarch butterflies (Danaus plexippus) and bees would benefit from them as well. They specifically wondered if monarchs would use cultivars at the same rate they chose wild species, whether for laying eggs, or for rearing their young.

One of the six experimental gardens showing variation in height, form and bloom color among the native milkweed species and cultivars. Credit: Credit: Adam M. Baker

The team conducted an experiment using two milkweed species — swamp and butterfly milkweed — as well as three of their respective cultivars. They set up six gardens with different varieties of the plants. Each garden block had four plants of each type. “We were mainly looking at the comparison between cultivars and wild types,” Baker said.

They grew the plants for two years, and every other week they counted the number of monarch eggs and larvae on individual plants. They also looked at the defensive characteristics of the plants including the latex that exudes from the leaves and the compounds that monarch butterflies sequester for their own chemical defense. Finally, they looked at which plants the caterpillars consumed the most by measuring the weight and development stages of the monarchs on the different plants. The team also looked at the bee communities by collecting samples from the different varieties. They identified more than 2,400 bees from five bee families and 17 genera.

In terms of monarch colonization, the researchers found no difference between the wild plants and the cultivars. This told the team that female monarchs looking to lay eggs aren’t going to discern between the two and that both are suitable for egg laying. The team also found that both types of plants were nutritionally viable. “We found absolutely no differences between cultivars and wild types in terms of growth and development of their larvae,” Baker said.

For the defensive metric, the team did find a bit of a difference. One of the cultivars, a white flowered swamp milkweed called Ice Ballet, stood out. It had greater amounts of latex and defensive compounds than wild types, they found, but not enough to influence the growth and development of caterpillars.

“I think the story is, monarchs are pretty adaptive and slight changes in defensive characteristics are easily overcome,” Baker said, “although other studies have shown that something like selecting for red leaf color may change the chemistry of the leaf and make it harder for them to digest.” The cultivated milkweeds in this study behaved very similarly to the wild types, Baker said, this is good news as people who plant these types of flowers in their gardens as they still benefit monarchs and other pollinators.

Bees, on the other hand, saw a positive effect from the cultivars. “As far as bees were concerned, there most certainly were benefits and interesting things going on,” he said. Some of them had much greater diversity of bee species visiting them than the wild types.

“What it means to me is that at least in this system, it is OK to incorporate ornamental varieties in gardening,” he said. “We would never promote putting them into native areas or in nature centers, but for a garden setting, they seem to be OK.”

Washington tracks Asian giant hornet to nest for first time

October 27, 2020 by The Wildlife Society

Washington State Department of Agriculture entomologists have tracked a nonnative Asian giant hornet back to its nest for the first time. After collecting three hornets, the team fitted them with radio trackers using glue and dental floss and followed one back to its nest in a tree cavity on private property in the town of Blaine. The entomologists saw dozens of hornets entering and exiting the nest in the tree, which came as a surprise, since the species usually uses ground nests. The property owner gave the state permission to remove the nest, and the WSDA Pest Program vacuumed out numerous Asian giant hornets (Vespa mandarinia). Nicknamed the “murder hornet” for the way it decapitates its prey, the insect kill honeybees that pollinate crops and eats ripe fruit on the trees. They are also known to attack paper wasp nests and yellow jackets in the area. The hornet was first seen in Washington in December, its first known appearance in North America.

Read more at WSDA.

Virtual section and chapter meetings in November

October 26, 2020 by The Wildlife Society

In light of the COVID-19 pandemic, many of The Wildlife Society’s sections and chapters have transitioned to virtual meetings. The following meetings are currently scheduled for November:

November 17, 2020: Maryland-Delaware Chapter virtual fall meeting

  • Meeting will begin at 9:30 a.m. EST and will use Microsoft Teams platform.
  • Tentative topics will include Delmarva fox squirrels, bobcats, how COVID-19 has impacted wildlife work, and diversity and inclusion in the wildlife field.
  • More details and registration to come. Check the chapter’s website for updates.

November 18, 2020: Wyoming Chapter and Central Mountains and Plains Section joint virtual conference

  • Conference is free to attend, but registration is required.
  • Meeting will begin at 8:15 a.m. View the full schedule here.
  • Please note, separate registration is required for the Wyoming Chapter board meeting and the CMPS business meeting.
  • Further details may be found at http://wytwsconference.org/.

Seven condors soon to be released in central California

October 26, 2020 by The Wildlife Society

Fresh off the setback of losing a number of birds to the Dolan Fire, conservationists are set to release seven new birds into the wild. The Dolan Fire destroyed a California condor sanctuary run by the Ventana Wildlife Society. The fire also led to the disappearance of nine condors as well as the death of two chicks, when the region they lived in near the sanctuary was burned as well. The Society will release the young birds in mid-November.

Read more at The Mercury News.

Wild Cam: Discovering Cape Town’s little known urban cats

October 26, 2020 by Joshua Rapp Learn

The urban felines paw the beach sands, cross highline pipes and move through people’s backyards in Cape Town, but they are far from the typical house cat. Caracals, researchers have found in an ongoing study, have carved out a niche in the South African city.

“Caracals are extremely flexible, behaviorally,” said TWS member Laurel Serieys, a postdoctoral researcher at the University of Cape Town, who presented her ongoing research at The Wildlife Society’s virtual 2020 Annual Conference.

Serieys had long been interested in the effects of urbanization on wild cats, but she couldn’t find much research published about urban felids in Africa.

“I wanted to get outside of North America and learn about urban wildlife in a lesser known place,” she said.

Caracals (Caracal caracal) are medium-sized cats a little larger than a bobcat (Lynx rufus). The ruddy brown felines have short tails — a little larger than a bobcat’s — and long tufts on their ears.

Serieys started the Urban Caracal project to track the little known cats in Cape Town.

Starting in late 2014, she and her colleagues captured and collared the cats to learn more about the population in the area, including what they ate and what types of environments they used. In total, they captured 29 cats and collared 26 of them with GPS tracking devices.

In the ongoing research, they are reviewing the GPS data to find clusters in particular areas that might indicate where they are feeding.

“We went on the ground and investigated more than 600 sites where clusters formed to look for prey remains,” Serieys said. They also collected about 700 scat samples to analyze the urban cats’ diets.

Cape Town caracals had a diverse diet, they found. From dissecting scat and examining suspected kill sites based on GPS clusters, they detected more than 70 prey species, particularly medium-sized birds and native rats. They were also seen eating frogs, as in the photo.

The diet information and the GPS coordinates collected from collars showed they like to spend their time on the coastline, where they hunt seabirds. That sometimes gets caracals into trouble with local wildlife managers, Serieys said, since they’ve been known to occasionally prey on African jackass penguins (Spheniscus demersus), classified as endangered by the International Union for Conservation of Nature.

“The caracals that enter the colony end up being captured and euthanized by the city,” Serieys said.

This isn’t the only trouble they get into in the city — and for that matter, in the rest of the country. They often prey on domestic cats, chickens and ducks. “In South Africa, they’re definitely a conflict species,” she said. “In agricultural areas, they are heavily persecuted by farmers.”

The movement patterns researchers revealed show that the main population of cats are confined to a peninsula isolated by the City of Cape Town. Genetic surveys suggest these cats there have high levels of inbreeding, so it appears to be a closed off population. There are only about 320 square kilometers available to them there, and a typical male territory in other areas is about 75 square kilometers.

A rough estimate would put about 50 cats in the area, which likely means heavy competition in a small territory, Serieys said. Her team has even detected caracals killing and eating other caracals.

Their data also showed that the cats prefer to spend time right at the edge of the urban areas, where they might encounter increased foraging opportunities. Samples from two subpopulations show the ones with a more fragmented habitats are more likely to get closer to urban edges than those that have more contiguous landscapes. Serieys said this shows that those urban cats may have become habituated to exploiting food sources near humans.

But they aren’t necessarily changing their behavior to avoid humans, she said. “We’re not detecting altered activity patterns in response to human activity.”

But living near urban edges may bring the urban cats problems, she said. Testing blood and liver tissue revealed that these caracals have widespread exposure to anticoagulant rodenticides and even illegal DDT. But like other urban animals, the caracals of Cape Town are most often killed by vehicles.

This photo essay is part of an occasional series from The Wildlife Society featuring photos and video images of wildlife taken with camera traps and other equipment. Check out other entries in the series here. If you’re working on an interesting camera trap research project or one that has a series of good photos you’d like to share, email Joshua at jlearn@wildlife.org.

TWS2020: Photos reveal endangered nyala in Ethiopian park

October 23, 2020 by Joshua Rapp Learn

A trail camera study in Ethiopia’s Bale Mountains has revealed the presence of endangered mountain nyalas in an area where the antelopes previously had not been known.

“They are usually found in an area farther away,” said Phyllis Gichuru, a master’s student at Virginia Polytechnic Institute and State University and one of the authors, who presented a poster on the ongoing research at The Wildlife Society’s virtual 2020 Annual Conference. Typically, mountain nyalas are found in more rugged areas with thicker vegetation.

Researchers were looking for a melanistic leopard they’d heard about but only saw some with more common colors. Credit: Chrystina Parks

She and her colleagues wanted to get a better idea of the types of mammals that live in Bale Mountains National Park, a large area southeast of the nation’s capital, Addis Ababa. They had heard of a black leopard (Panthera pardus pardus) in the area and a lion that was used to living in dense vegetation as opposed to the usual savannah were they are found. They were also curious to see if Ethiopian wolves (Canis simensis), listed as endangered by the International Union for Conservation of Nature, were in the area, even though they are typically found at higher elevations.

The Bale Mountains is a unique ecosystem but it’s also in demand for coffee growing and livestock herding. Gichuru also wanted to learn more about human-wildlife interactions in the area, which is the last remaining pristine Afro-alipine biodiversity hotspot, sitting in the largest most contiguous mountain range in Africa.

Crested porcupines (Hystrix cristata). Credit: Chrystina Parks

From December 2015 to March 2016, her colleagues Matt Thornton and Chrystina Parks set up about 80 cameras around the park. They collected photos from about 50 of them after some were stolen and others destroyed by cattle herds moving through the area in dryer months.

The team gathered enough information to look at 27 different species of mammals in the park, including the mountain nyala (Tragelaphus buxtoni). Endemic to Ethiopia, the antelope is considered endangered by the International Union for Conservation of Nature due to threats including hunting, habitat loss, grazing from cattle and habitat fragmentation. “We did not think we’d see mountain nyalas in that area,” Gichuru said.

A common genet. Credit: Chrystina Parks:

They also found evidence of wildlife such as lions (Panthera leo), spotted hyenas (Crocuta crocuta), Ethiopian genets (Genetta abyssinica) and leopards, though they didn’t see the melanistic individual they’d heard about.

Gichuru said the researchers are still analyzing the data, but preliminary results show that honey badgers (Mellivora capensis) and African civets (Civettictis civetta) are found more often at higher elevations. Human-wildlife conflicts seem to be ongoing in the area, involving a number of different species.

This research was presented at TWS’ 2020 Virtual Conference. Conference attendees can continue to visit the virtual conference and review Gichuru’s paper for six months following the live event. Click here to learn about how to take part in upcoming conferences.

U.S. Fish and Wildlife Service launches new permitting system

October 23, 2020 by The Wildlife Society

The U.S. Fish and Wildlife Service has launched a new electronic permitting system for dealing with protected species.

The new permitting system, or ePermits, will help simplify and expedite the permitting process,” said Aurelia Skipwith, director of the U.S. Fish and Wildlife Service, in a press release.

This permitting system will affect people applying for permits issued for activities like the import or export of animals, plants or biomedical samples, the rehabilitation of migratory birds, exchange of specimens between museums, scientific research or reintroduction programs.

“Permits from the Service are integral to the work of many ornithologists, so we are excited about the new ePermits system,” said Laura Bies, Executive Director of The Ornithological Council and The Wildlife Society’s government affairs consultant. “This new system has the potential to reduce the paperwork burden for researchers and scientists, and the Ornithological Council looks forward to its implementation.”

The government will continue to make enhancements to the online system through July 2021.

Watch: How barn owls fly in rough winds

October 23, 2020 by The Wildlife Society

Analysis of slow-motion video has revealed how some birds adapt to flying in rough winds. In a study, published recently Proceedings of the Royal Society B, researchers show how barn owls (Tyto alba) manage to fly close to buildings or other terrain features and cope with sudden wind direction changes. They found that the owls, including one they named Lily, morph the shape of their wings in mid-flight. “Lily flew through the bumpy gusts and consistently kept her head and torso amazingly stable over the trajectory, as if she was flying with a suspension system,” said lead-author Jorn Cheney from the Royal Veterinary College in a press release. “When we analyzed it, what surprised us was that the suspension-system effect wasn’t just due to aerodynamics, but benefited from the mass in her wings.” The study is the first of several steps in developing bio-inspired suspension systems for aircraft.

Read the study at Proceedings of the Royal Society B.

TWS expresses concerns about new training guidance

October 22, 2020 by Laura Bies

The Wildlife Society wrote to the heads of the U.S Office of Management and Budget and the Office of Personnel Management regarding recent guidance from the Trump administration that the Society is concerned will affect federal agencies’ efforts to promote and encourage diversity among their professional workforce.

Executive Order 13950 on Combating Race and Sex Stereotyping issued on Sept. 22, 2020, along with three recent Memorandums for the Heads of Executive Departments and Agencies  issued in September and October, called on federal agencies to review all diversity and inclusion training to ensure it does not promote “offensive and anti-American race and sex stereotyping and scapegoating.” Agencies must review their training offerings and report back within 90 days.

“We urge the administration to reinforce its support for diversity, equity and inclusion among the federal workforce and lift these restrictions for federal employees, contractors and grant recipients from engagement in diversity and inclusion training,” said Jamila Blake, AWB®, professional development manager at The Wildlife Society. “Improving awareness of historic racial and gender relations and current workforce conditions enhances professionals’ ability to engage meaningfully in the conservation workforce and with the public to advance science-based conservation.”

The effect of the administration’s order and subsequent guidance has been to delay or cancel trainings related to diversity, equity, inclusion and other topics among Department of the Interior and other agencies.

The Society’s letter stressed that training focused on diversity, equity and inclusion is integral to expanding knowledge and understanding barriers, challenges and opportunities to create and sustain a welcoming professional culture. Promoting a professional culture that welcomes individuals from diverse backgrounds fosters a richness of perspectives, values, and contributions necessary for strengthening and improving our approaches to research, education, management and policy making.

The Wildlife Society is committed to recruitment, effective mentoring, retention of a diverse workforce, and to communicating with a diverse array of stakeholders. Through ongoing diversity initiatives, TWS has been working with partners and members to develop recommendations for increasing recruitment and retention of underrepresented groups. Society members and staff have developed resources and publications to further advance diversity, equity, and inclusion in the wildlife profession.

Read TWS’ Standing Position on Workforce Diversity within the Wildlife Profession