Skip to Main Content
Diets of California spotted owls in the Sierra National ForestAuthor(s): Thomas E. Munton; Kenneth D. Johnson; George N. Steger; Gary P. Eberlein
Source: In: Verner, Jared, tech. editor. Proceedings of a Symposium on the Kings River Sustainable Forest Ecosystem Project: Progress and Current Status. Gen. Tech. Rep. PSW-GTR-183, Albany, CA: Pacific Southwest Research Station, Forest Service, U.S. Department of Agriculture: 99-106
Publication Series: General Technical Report (GTR)
Station: Pacific Southwest Research Station
PDF: Download Publication (260 KB)
DescriptionFrom May 1987 through October 1992 and from July through August 1998, we studied diets of California spotted owls (Strix occidentalis occidentalis). Regurgitated pellets were collected at roost and nest sites between 1,000 and 7,600 ft elevation in the Sierra National Forest and were examined for remnant bones, feathers, and insect exoskeletons. Remains of 2,038 individual prey were identified in 1,140 pellets. Woodrats (Neotoma spp.) were the predominant prey in low-elevation oak woodlands and riparian-deciduous forests, accounting for 74.3 percent of the biomass in diets during the breeding period and 81.9 percent during the nonbreeding period. In coniferous forests, northern flying squirrels (Glaucomys sabrinus) were the major prey, comprising 45.6 percent and 77.3 percent of prey biomass during the breeding and nonbreeding periods, respectively. Pocket gophers (Thomomys spp.) were the second largest component of owl diets, by biomass, in both vegetation types. In the breeding period, birds were a larger part of the owl’s diet in coniferous forests (12.9 percent) than in the riparian-deciduous and oak habitats (1.8 percent). Other small mammals, insects, and lizards were also found in pellets. Diets differed among years.
- You may send email to email@example.com to request a hard copy of this publication.
- (Please specify exactly which publication you are requesting and your mailing address.)
- We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
- This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.
CitationMunton, Thomas E.; Johnson, Kenneth D.; Steger, George N.; Eberlein, Gary P. 2002. Diets of California spotted owls in the Sierra National Forest. In: Verner, Jared, tech. editor. Proceedings of a Symposium on the Kings River Sustainable Forest Ecosystem Project: Progress and Current Status. Gen. Tech. Rep. PSW-GTR-183, Albany, CA: Pacific Southwest Research Station, Forest Service, U.S. Department of Agriculture: 99-106
- An apparent case of long-distance breeding dispersal by a Mexican spotted owl in New Mexico
- Association of weather and nest-site structure with reproductive success in California spotted owls
- Comparative habitat use of sympatric Mexican spotted and great horned owls
XML: View XML