Nov 23, 2024

Drought delivers a big blow to wildlife already grappling with disease and habitat loss

Posted Nov 23, 2024 10:30 AM
A student from the University of Nebraska-Lincoln holds a painted turtle from a pond in western Nebraska. Data from this turtle population showed how drought conditions may impact painted turtles, such as slowing growth and lowering survival. Photo by Elizabeth Rembert/Harvest Public Media
A student from the University of Nebraska-Lincoln holds a painted turtle from a pond in western Nebraska. Data from this turtle population showed how drought conditions may impact painted turtles, such as slowing growth and lowering survival. Photo by Elizabeth Rembert/Harvest Public Media

By ELIZABETH REMBERT
Harvest Public Media 

Drought has scorched much of the Midwest and Great Plains for the last four years. It has destroyed crops and sparked wildfires. Wildlife is also reckoning with the dry conditions – which can change animal behavior and even push species out of some regions.

A small pond sits near the end of County Road F in western Nebraska, shaded by cottonwood trees that rustle in the gentle wind.

At first, it looks like a typical pond off a quiet, dead-end gravel road. But after nearly twenty years of visiting this pond, Larkin Powell is pretty good at spotting its residents.

“Look at all the heads, the little bumps sticking up in the water?” the University of Nebraska-Lincoln professor of biology and ecology points out. “Those are the turtles.”

Larkin Powell teaches conservation biology and animal ecology at the University of Nebraska-Lincoln, where he also leads the School of Natural Resources. He’s been visiting the painted turtle pond for nearly 20 years to teach students how to capture and measure wild animals. Elizabeth Rembert/Harvest Public Media
Larkin Powell teaches conservation biology and animal ecology at the University of Nebraska-Lincoln, where he also leads the School of Natural Resources. He’s been visiting the painted turtle pond for nearly 20 years to teach students how to capture and measure wild animals. Elizabeth Rembert/Harvest Public Media

Each summer, Powell rounds up students and arms them with thick gloves, calipers and scales to catch and measure the painted turtles that call this pond home.

A handful of turtles were naive enough to mistake the floating traps as perches for sunbathing, and now they’re scratching around in buckets, waiting their turn to be measured by the crew of students.

Powell and his students analyzed 11 years of data to study how drought conditions impacted the turtles. They found that during dry years, the turtles grew more slowly. The conditions also seemed to lower survival and throw off the female to male ratio.

A student from the University of Nebraska-Lincoln holds a painted turtle from a pond in western Nebraska. Data from this turtle population showed how drought conditions may impact painted turtles, such as slowing growth and lowering survival. Photo by Elizabeth Rembert/Harvest Public Media
A student from the University of Nebraska-Lincoln holds a painted turtle from a pond in western Nebraska. Data from this turtle population showed how drought conditions may impact painted turtles, such as slowing growth and lowering survival. Photo by Elizabeth Rembert/Harvest Public Media

The papers have been Powell’s most-requested research studies in the last few years. While painted turtles are a stable population that aren’t existentially threatened by drought, Powell said the findings could be applied to other endangered species that might need help as they reckon with climate change’s extreme conditions.

“Now that droughts are becoming more frequent and more intense, there’s going to be some changes,” he said. “We have to account for that as we think about the future for species of conservation concern.”

Drought conditions

The last few years of drought have been especially severe. In early November, more than 79% of the country’s population was living with abnormal dryness and drought, a record in the U.S. Drought Monitor’s 25-year history.

Much of the Midwest and Great Plains have been dealing with extremely dry conditions for the past four years. It’s killed crops, lowered river levels and fueled wildfires.

States like Iowa, Nebraska and Minnesota experienced their driest September on record this year. The conditions follow a reprieve from drought earlier this summer, according to Molly Woloszyn with the National Integrated Drought Information System.

“Conditions were still OK, until we hit the fall where precipitation has turned off for many, many locations,” Woloszyn said. “We had a feeling that if the rain stopped, things were going to get dry pretty quickly, and that's pretty much what we have seen.”

High Plains drought map on Nov. 19, 2024. Image by U.S. Drought Monitor
High Plains drought map on Nov. 19, 2024. Image by U.S. Drought Monitor

Persistently high temperatures and low precipitation has also transformed creeks and ponds into puddles in Kansas and Missouri. It’s killed off fish and ruined habitats for migrating birds.

In Indiana, the extreme heat and dryness of the 2012 drought wiped out the Karner butterfly. The small, powder blue butterfly hasn’t been seen there since 2014.

Other animals are showing up where they shouldn’t be. Like in St. Louis, which saw a handful of wild black bears venture into suburban neighborhoods at different points this summer.

Black bears usually prefer to stay away from people, but Missouri Department of Conservation biologist Nate Bowersock said they’re more willing to risk human contact when dry conditions kill the acorns and berries they rely on. That may mean they wander into the suburbs or onto farms.

“They might start trying to flip over a chicken coop to get at the chickens or just decimate a beehive if it’s not properly secured,” Bowersock said. “Bird feeders, too. They love to go after people’s bird feeders.”

The wild black bears that roam into developed areas are often young bears trying to find food in a new territory, according to biologist Nate Bowersock. Drought conditions that make native fruits and acorns scarce can force bears into closer contact with humans. Photo by Noppadol Paothong/ Missouri Department of Conservation
The wild black bears that roam into developed areas are often young bears trying to find food in a new territory, according to biologist Nate Bowersock. Drought conditions that make native fruits and acorns scarce can force bears into closer contact with humans. Photo by Noppadol Paothong/ Missouri Department of Conservation

Missouri’s rich forests, long growing season and abundance of native fruits and nuts give bears an advantage when it comes to surviving dry periods, according to Bowersock. But he said the department is still thinking of drought’s impacts.

“With climate change, conditions are happening a lot quicker than some animals can handle,” he said. “It just makes it vital for us to stay on top of how droughts affect the plants that bears rely on, so that our management decisions are really what’s best for the bears.”

Droughts getting worse

While droughts are a part of the natural weather cycle, scientists have found that human-caused climate change is making them more frequent and more intense. The extreme conditions are putting wildlife’s coping mechanisms to the test.

But that’s only half the story, according to Wynne Moss, a biologist with the U.S. Geological Survey.

“The other half is that the ecosystem's ability to withstand water shortages is also changing,” she said. “So even the same degree of drought might now have bigger impacts.”

Moss said wildlife is also fighting off new levels of disease, invasive species and habitat loss.

“Drought adds another threat to that list,” she said. “And it can be the death blow for some of these species.”

The threat is becoming more persistent. Even when drought conditions ease, Moss said the effects can stick around.

“Ecosystems recover very slowly. It can take years, and in some cases you might have no recovery at all,” she said. “But the droughts are happening so fast that ecosystems are finding it challenging to fully recover before the next drought happens.”

Scott White, manager of the Klamath Drainage District in southern Oregon, knows that phenomenon well. Over the past 15 years, his area has received 10 drought declarations from the governor.

“Dealing with drought and climate change is a new way of life for us,” he said.

The conditions dried up water sources in a nearby National Wildlife Refuge, which has served as a prime resting spot for waterfowl migrating south. When the waterways dried up, the birds stopped coming.

It shut down the hunting season and killed a major economic engine for the region. Before the drought, White said bird-cleaning stands lined the roads during hunting season.

“It was like lemonade stands,” he said. “You could go out hunting in the morning, stop at a stand and have somebody clean your birds for you, and you’re on your way home.”

But that stopped when the refuges dried up.

“It’s been a long, long time since that type of economy existed here,” he said. “It was an eye-opener for the entire community. Waterfowl hunting was a huge, huge part of our identity and our economy.”

White and others are now working on a project to rework the district’s canals to reconnect waterways in the region, feeding the refuge’s pools to allow fish to access the wetlands and provide protections for animals and landowners.

“We just know that keeping the refuges dry is not a solution,” he said. “So we’re looking at these other alternatives to try and find a way to secure our future and bring back waterfowl, recover fisheries and not impact our neighbors in a negative way.”

A pair of turtles return to the pond after being measured and weighed. The data and analysis could help other endangered species that might need assistance surviving drought, especially as climate change makes dry spells more frequent and intense. Photo by Elizabeth Rembert/Harvest Public Media
A pair of turtles return to the pond after being measured and weighed. The data and analysis could help other endangered species that might need assistance surviving drought, especially as climate change makes dry spells more frequent and intense. Photo by Elizabeth Rembert/Harvest Public Media

Back at the pond in western Nebraska, the turtles have done their scientific duty. It’s time for them to go back home.

The students walk down to the pond, set the buckets on their sides and watch as the turtles slowly make their way to the water. They float on the surface before swimming out, only their little heads visible above the water.

Powell said studying drought’s impacts on parts of wildlife can shed light on how extreme conditions may play out on a greater scale.

“Pollinators and insects support our entire ecosystem. And if they’re impacted, other things in the system are going to be impacted, too,” he said. “Even if you don’t really care about turtles, this may be a lesson that if these dynamics out on the landscape can affect turtles, they can affect you, too.”

This story was produced in partnership with Harvest Public Media, a collaboration of public media newsrooms in the Midwest. It reports on food systems, agriculture and rural issues.