More Owls Nest at Gillmor Sanctuary Thanks to New Digs—Literally!

Staff, partners, and volunteers have been busy at Audubon’s Gillmor Sanctuary along Great Salt Lake. Ongoing restoration projects have seen over a thousand acres of invasive tamarisk trees removed, and many areas have also been hand-seeded with native grasses, shrubs, and forbs. Removal of the invasive trees cleared the way for these native plants to rebound, and for native wildlife to return.

This includes Burrowing Owls, a unique, ground-dwelling species that prefers open, treeless landscapes with short, sparse vegetation. But even after removing the tamarisk and seeding, there was still one missing component for the Burrowing Owls to thrive at the sanctuary: nesting sites!

Over time, many of the natural burrows at the sanctuary that owls have nested in—dug by prairie dogs, badgers, desert tortoises, and other wildlife— have collapsed. Burrow collapses happen naturally but can be accelerated when large animals, such as cattle and bison, frequently walk or wallow above the sites. While a handful of natural burrows exist at the sanctuary, we wanted to actively increase nesting opportunities.

Setting Up the Sites

To do this, Audubon asked for the help of the incredible network of community conservation partners and volunteers in the Salt Lake Valley. We built reinforced artificial nest burrows using upcycled materials. These burrows can withstand the weight of large mammals walking above and be maintained as needed. 

Nest sites were also carefully chosen. All were placed in areas where invasive vegetation had been removed and owls had open views of the surrounding landscape. This visibility allows the owls to detect approaching predators while also providing access to short grasslands and sparse shrub cover where they hunt rodents, insects, reptiles, and small birds. 

Organizations including HawkWatch International, Tracy Aviary, Sageland Collaborative, Friends of Great Salt Lake, Great Salt Lake Institute, The Jordan River Commission, Salt Lake Community College, Boy Scouts of America, and many dedicated volunteers joined Audubon’s Gillmor Sanctuary and Saline Lakes teams in the field. Together, with shovels in hand, 18 artificial burrows were installed, creating nine new nest sites. With plans to dig 14 more, our grand total will be 32 burrows and 16 nesting sites.

Whooo’s Moved In?

Spring and summer 2026 has been the first nesting season since the burrows were installed. We expected it may take up to two years for nesting pairs to show up. However, seven out of nine sites already have a nest! One burrow was occupied just three days after being installed. Each site has been observed over the nesting season and we are excited to report every nest has successfully fledged owlets.

These early results suggest that habitat restoration combined with artificial nesting burrows can be a highly effective strategy for supporting Burrowing Owl populations. Owls are using the sites, nesting successfully, and raising young in areas that only a few years ago were crowded by invasive vegetation and lacking suitable burrows.

Audubon will restore additional habitat at Gillmor Sanctuary while building and maintaining Burrowing Owl nesting sites. Monitoring nesting sites will also help us understand how grassland species respond to habitat restoration and which practices best support Burrowing Owls and other local species in the area. Audubon, in partnership with HawkWatch International, will continue to study the health and trends of local Burrowing Owl populations to gain insight into encouraging populations of this charismatic species.

A saw, a shovel, some seed, and a dedicated community have made a positive difference for grassland birds in our corner of the Great Salt Lake ecosystem. 

Restoration efforts on Gillmor Sanctuary’s uplands also go beyond artificial burrows. Learn how Audubon is encouraging more Burrowing Owls to nest at the sanctuary by cutting down invasive trees. Read more. To learn more about Gillmor Sanctuary, click here.
 

We would like to extend a huge thank you to all of the organizations and volunteers who made this work possible. Thank you, also, to the Nation Fish and Wildlife Federations’ America the Beautiful Challenge Grant and Browning Foundation for funding this important work.