Density, Distribution and Food Habits of Mexican Spotted Owls in Zion National Park
Rinkevich SE. 1991. Density, Distribution and Food Habits of Mexican Spotted Owls in Zion National Park. National Park Service. Springdale, UT
Distribution, density and food habits of Mexican spotted owls (Strix occidentalis lucida) were investigated from 10 March 1991 - 25 August 1991 in Zion National Park. Seven Bureau of Land Management Land (BLM) - Wilderness Studyness Study Areas (WSAs) adjacent to park boundaries were also surveyed. I located 11 pair and 3 single male spotted owls in 14 different canyon locations scattered throughout the park. Of the 14 locations, 2 were on WSAs and also were included in the density estimate. The minimum estimated density in Zion Park was 0.04 owls/km^2. Prey items found in 112 pellets collected included bushy-tailed woodrats (Neotoma cinerea), desert woodrats (Neotoma lepida), mice (Peromyscus spp.) and beetles (Coleoptera). Woodrats (Neotoma spp.) comprised 57.2% of the total diet composition and 97.7% of the estimated biomass. Invertibrates comprised 29.5% of the total diet composition but contributed less than 0.1% of estimated biomass. Two male spotted owls in Zion Park and one male spotted owl in Spring Creek Canyon WSA were equipped with tail mounted radio transmitters. Owls were tracked throughout the summer during the hours from 2200 and 0600. Mexican spotted owl research must continue to ensure viable populations in Zion National Park and surrounding land agencies. This information is needed to evaluate current management practices.
- Type
- Unpublished Report
- Authors
- Rinkevich, Sarah
- Date of Issue
- 1991-09-09
- Publisher
- National Park Service
- Units
- ZION
- Keywords
- Animal Behavior, Animal Studies, Animals, Biology, Birds, Birds (Aves), capture techniques, Census, Habitats, Insects (Insecta), Inventory, Inventory & Monitoring, Invertebrates (Invertebrata), Mammals, Monitoring, Raptors, Release (Species), Remote Sensing, Research & Studies, Rodents (Rodentia), Spotted Owl (Strix occidentalis), Threatened-Endangered-Sensitive Animals