This article was originally featured on Undark.
“This is one of the least smelly carcasses,” said Todd Katzner, peering over his lab manager’s shoulder as she sliced a bit of flesh from a dead pigeon lying on a steel lab table. The specimens that arrive at this facility in Boise, Idaho, are often long dead, and the bodies smell, he said, like “nothing that you can easily describe, other than yuck.”
A wildlife biologist with the U.S. Geological Survey, a government agency dedicated to environmental science, Katzner watched as his lab manager rooted around for the pigeon’s liver and then placed a glossy maroon piece of it in a small plastic bag labeled with a biohazard symbol. The pigeon is a demonstration specimen, but samples, including flesh and liver, are ordinarily frozen, catalogued, and stored in freezers. The feathers get tucked in paper envelopes and organized in filing boxes; the rest of the carcass is discarded. When needed for research, the stored samples can be processed and sent to other labs that test for toxicants or conduct genetic analysis.
Most of the bird carcasses that arrive at the Boise lab have been shipped from renewable energy facilities, where hundreds of thousands of winged creatures die each year in collisions with turbine blades and other equipment. Clean energy projects are essential for confronting climate change, said Mark Davis, a conservation biologist at the University of Illinois at Urbana-Champaign. But he also emphasized the importance of mitigating their effects on wildlife. “I’m supportive of renewable energy developments. I’m also supportive of doing our best to conserve biodiversity,” Davis said. “And I think the two things can very much coexist.”
To this end, Katzner, Davis, and other biologists are working with the renewable energy industry to create a nationwide repository of dead birds and bats killed at wind and solar facilities. The bodies hold clues about how the animals lived and died, and could help scientists and project operators understand how to reduce the environmental impact of clean energy installations, Davis said.
The repository needs sustained funding and support from industry partners to supply the specimens. But the collection’s wider potential is vast, Davis added. He, Katzner, and other stakeholders hope the carcasses will offer a wide array of wildlife biologists access to the animal samples they need for their work, and perhaps even provide insights into future scientific questions that researchers haven’t thought yet to ask.
In 1980, California laid the groundwork for one of the world’s first large-scale wind projects when it designated more than 30,000 acres east of San Francisco for wind development, on a stretch of land called the Altamont Pass. Within two decades, companies had installed thousands of wind turbines there. But there was a downside: While the sea breeze made Altamont ideal for wind energy, the area was also well-used by nesting birds. Research suggested they were colliding with the turbines’ rotating blades, leading to hundreds of deaths among red-tailed hawks, kestrels, and golden eagles.
“It’s a great place for a wind farm, but it’s also a really bad place for a wind farm,” said Albert Lopez, planning director for Alameda County, where many of the projects are located.
A 2004 report prepared for the state estimated deaths and offered recommendations that the authors said could add up to mortality reductions of anywhere from 20 to 50 percent. The most effective solution, the authors argued, involved replacing Altamont’s many small turbines with fewer larger turbines. But, the authors wrote, many measures to reduce deaths would be experimental, “due to the degree of uncertainty in their likely effectiveness.” More than a decade of research, tensions, and litigation followed, focused on how to reduce fatalities while still producing clean electricity to help California meet its increasingly ambitious climate goals.
While all this was happening, Katzner was earning his Ph.D. by studying eagles and other birds — and beginning to amass a feather collection halfway around the world. In Kazakhstan, where he has returned nearly every summer since 1997 to conduct field research, Katzner noticed piles of feathers underneath the birds’ nests. Carrying information about a bird’s age, sex, diet, and more, they were too valuable a resource to just leave behind, he thought, so he collected them. It was the start of what he describes as a compulsion to store and archive potentially useful scientific material.
Katzner went on to co-publish a paper in 2007, in which the researchers conducted a genetic analysis of naturally shed feathers, a technique that could allow scientists to match feather samples with the correct bird species when visual identifications are difficult. He later towed deer carcasses across the East Coast to lure and trap golden eagles in order to track their migration patterns. And today, part of his research involves testing carcasses for lead and other chemicals to understand whether birds are coming in contact with toxicants.
For the last decade, Katzner has also researched how birds interact with energy installations like wind and solar projects. During this time, studies have estimated that hundreds of thousands of birds die each year at such facilities in the United States. Thats’s still a small fraction of the millions of birds that at least one paper estimated are killed annually due to habitat destruction, downstream climate change, and other impacts of fossil fuel and nuclear power plants. But renewable energy is growing rapidly, and researchers are trying to determine how that continued growth might affect wildlife.
Bats seem attracted to spinning wind turbines, sometimes being struck by the blades while attempting to roost in the towers. Birds sometimes swoop down and crash into photovoltaic solar panels — possibly thinking the glass is water that is safe for landing. A separate, less common solar technology that uses mirrors to concentrate the sun’s rays into heat energy is known to singe birds that fly too close — a factor that has drawn opposition to such facilities from bird activists. But scientists still don’t fully understand these many interactions or their impacts on bird and bat populations, which makes it harder to prevent them.
In 2015, by then on staff at the USGS, Katzner and a team of other scientists secured $1 million from the California Energy Commission to study the impacts of renewable energy on wildlife — using hundreds of carcasses from the Altamont Pass. NextEra Energy, one of the largest project owners there, chipped in a donation of approximately 1,200 carcasses collected from their facilities in Altamont.
The team analyzed 411 birds collected over a decade at Altamont and another 515 picked up during a four-year period at California solar projects. They found that the birds originated from across the U.S., suggesting renewable facilities could affect far away bird populations during their migrations. In early 2021, Katzner and a team of other scientists published a paper examining specimens collected at wind facilities in Southern California. Their results suggested that replacing old turbines with fewer, newer models did not necessarily reduce wildlife mortality. Where a project is sited and the amount of energy it produces are likely stronger determinants of fatality rates, the authors said.
In the Altamont, scientists are still working to understand impacts for birds and bats, with a technical committee created to oversee the work. Ongoing efforts to replace old turbines with newer ones are meant to reduce the number of birds killed there, but whether it’s working remains an open question, said Lopez. Installing fewer turbines that produce more energy per unit than earlier models was expected to provide fewer collision points for birds and more space for habitat. And when new turbines are put in, scientists can recommend spots within a project site where birds may be less likely to run into them. But other variables influence mortality aside from turbine size and spacing, according to the 2021 paper authored by Katzner and other scientists, like season, weather, and bird behavior in the area.
On a small road in the Altamont, a white sign marks an entrance to NextEra’s…