They lay their eggs up to 10 feet underground, deep in abandoned prairie dog tunnels.
During the day, they stand outside like sentinels — feathery, football-sized guards with heads that turn about 270 degrees.
Burrowing owls have been called one of the most mysterious birds in Wyoming largely because their breeding life takes place underground, out of sight.
But one thing researchers do know: Populations of one of the West’s most adorable owls are struggling.
“They are federally endangered in Canada… and they’ve declined greatly in Washington and California and in the eastern edge of their range, which has largely been converted to corn,” said Courtney Conway. “But there’s data to suggest they’re not doing too bad in Wyoming.”
Conway is the leader of the Idaho Cooperative Fish and Wildlife Research Unit. He’s been studying burrowing owls throughout the U.S. and Canada since the late ‘90s and has watched as their numbers decline. But all is not lost. As he works with agencies in Wyoming and across the country to better understand the owls and where they go in the winter, he and others hope to find key areas that, if improved, could help populations remain steady.
For burrowing owls, threats are two-fold: a loss of homes and food.
Unlike nearly all other owls, burrowing owls nest underground in prairie dog, ground squirrel, marmot or other tunnels. In Wyoming, only the short-eared owls nest anywhere but in trees, and they are on top of the ground.
The burrowing owl is one of the few birds in the world that breeds and lays eggs underground, Conway said. And they’re not capable of building their own tunnels. They can expand them, widen them, and clean them out, but they can’t create them on their own.
As Canada and the western U.S. became more settled, and burrowing critters like prairie dogs were exterminated, so, too, went the burrowing owls.
It’s why in places like Wyoming, the owls appear to have found even a bit of a stronghold.
“There’s a lot of wide-open range, and because of that it’s hard for ranchers and landowners to eradicate all of the prairie dogs and marmots and other critters,” he said. “I see more prairie dog hunters in Wyoming than anywhere else, but Wyoming is a big, open state, so even though I see more prairie dog hunters there are a lot of areas where there aren’t prairie dog hunters.”
The other threat is insect control.
More than a century ago, as the West was being settled, grasshoppers would rise in swarms so thick they blackened the sky and decimated crops. But as damaging as they were to farmers, they provided endless food for owls.
When the federal government began a formal eradication campaign, it saved crops but hurt species like burrowing owls that depended on the bugs for food.
“Burrowing owls are very adaptive to take advantage of those,” he said. “There hasn’t been a large outbreak like that in half a century because of the control efforts.”
Even though burrowing owl populations are doing relatively well in Wyoming, it’s important to understand the population as a whole, across their range, said Andrea Orabona, a nongame bird biologist with the Wyoming Game and Fish Department.
Burrowing owls migrate sometimes as far south as Mexico in the winter. The ones breeding on the eastern side of the Continental Divide head southeast, and the ones breeding on the western side head southwest. Where exactly the owls in Wyoming go is a bit of a mystery, but a mystery that matters.
“We see them in the western U.S., and then they disappear. Their declines could be along their migration routes or on their wintering grounds and not their breeding grounds,” Conway said.
Swainson’s Hawks, for example, were declining across the U.S. to the puzzlement of most researchers. Finally they realized it wasn’t an issue here, but because of DDT use on wintering grounds in South America. The birds were dying by the thousands. Once it was banned on their wintering grounds, their numbers rebounded.
“We can throw as much money as we have to help the species on the breeding grounds, but if that isn’t where the problems are we want to make sure we connect with partners in the migration routes and wintering areas,” Orabona said.
To find out where they go, researchers are spending weeks each summer trapping burrowing owls at their nests across Wyoming and many other western states. They place bands on their legs and tiny, solar-powered, GPS backpacks on their backs. A Teflon tape attaches them, and a long, flexible antennae runs out the top to provide the necessary signal.
What can be done to help the birds?
Primarily, stop eradicating quite so many burrowing animals, Conway said.
Number reductions are fine, he added, but if entire colonies are decimated by poison, the owls will also leave.
For anyone interested in seeing the long-legged fluffy guards, look for them in prairie dog towns throughout the summer, from early morning throughout the day. Use binoculars to scan slowly, said Orabona.
“They don’t like trees, so they only occur in very open areas,” said Conway. “Any time you see a burrowing owl, it’s a treat.”