The 2013 Rim Fire burned more than 78,000 acres in Yosemite, damaging important forest habitat for two sensitive species: the great gray owl and the spotted owl. Park biologists need to understand how fire affects habitats of these iconic birds in order to develop customized conservation plans.

Results from studies conducted in 2014 and 2015 showed that many of the owls have returned to their forest homes, even in burned areas. In 2016, scientists explored how the Rim Fire has influenced the owls’ breeding success by searching for and monitoring nests in burned and unburned areas. Using a combination of nocturnal surveys and meadow searches, the team recorded hundreds of detections of great gray and spotted owls, as well as of six other owl species. One of those species, the barred owl, was detected in Yosemite for the first time, and represents a threat to spotted owls: The two species look similar, but the invasive barred owl, which has moved west from its native habitat in the eastern U.S., is larger and more aggressive, and has a more diverse diet.

As part of this project, scientists also deveoped a new protocol for studying how great gray owls forage and select perches, with the goal of using their observations to help reduce the birds’ roadside mortality risk (in recent decades, more than 30 of Yosemite’s great gray owls have been killed in vehicle collisions).

Information gained through this research helps scientists build a more complete picture of fire’s effects on Yosemite’s flagship owl species, and could be used to inform future fire-management decisions. Ultimately, this project helps park scientists and resource managers protect the owls in their natural, fire-prone forest habitats.

Your contribution supported continued efforts to develop conservation plans and fire-management strategies to protect Yosemite’s cherished wildlife. Thank you for supporting your park!

Completed in partnership with Yosemite National Park, California Department of Fish & Wildlife, Institute for Bird Populations, National Science Foundation and Student Conservation Association. 


Sarah Stock

Wildlife Biologist

Project Notes

Protection of the great gray owl is one of the park's highest wildlife priorities. This project provides Sierra-wide leadership in the recovery and restoration of threatened species and their sensitive habitats. There will be both urgent direct action to protect endangered great gray owls, their nests, and juveniles, and long-term strategic action to track population trends, reverse any declines, and prevent extinction.