24892 – Territorial Interactions Between Species of Corvids

Investigator’s Annual Reports (IAR’s) for Crater Lake National Park

Territorial Interactions Between Species of Corvids


Report Number: 24892

Permit Number: CRLA-2002-SCI-0004

Current Status: Checked in

Date Received: Apr 10, 2003

Reporting Year: 2002

Principal Investigator: Dr Lawrence Powers, Department of Natural Sciences, Oregon Institute of Technology, Klamath Falls, OR

Additional investigator(s): Alan Buehrig, Alisha Simonson, Shawna Nieraeth

Park-assigned Study Id. # CRLA-00003

Permit Expiration Date: Sep 30, 2002

Permit Start Date: Jun 01, 2002

Study Starting Date: Jun 01, 2002

Study Ending Date: Sep 30, 2002

Study Status: Completed

Activity Type: Education

Subject/Discipline: Birds / Ornithology

Objectives: Characterize types of aggressive displays in and between corvid species of birds (Clark’s Nutcrackers, Stellar’s Jays, Gray Jays and Scrub Jays) at different elevations in the Klamath Basin and adjoining Cascades Mountains, including sites within Crater Lake National Park. Use ethological observations at potential interaction sites to characterize behaviors. Characterize, if possible, habitat sites and elevation zones for the four species.

Findings and Status:  Crater Lake National Park was one of several sites used in the Klamath basin to observe territorial interactions among four corvid species of birds. Within the park, observation sites included 1) Annie Creek picnic area near south entrance to park; 2) Annie Creek picnic area 3 miles inside park; 3) area north of Annie Creek Bridge; 4) Goodbye Picnic Area; 5) Godfrey Glen Trail parking area; 6) CLNP headquarters area; 7) pumice field halfway up road to Rim Drive; 8) Steel Bay overlook on West Rim Road; 9) Northeast Rim Road; 10) Cloudcap Overlook area; 11) 2 miles north of Pinnacles Road on East Rim Drive; 12) rock quarry on Sand Creek Fire Road; and 13) Flower Garden parking area. GPS coordinates and times of observation are available for each of these sites.

Four observers remained in each of these areas for 30 minutes to observe corvids. if no corvids were seen or heard, no further observations for that site were made. In general, nutcrackers were observed primarily at the Rim drive sites, with the exception of the Park Headquarters. Gray Jays were seen at most sites, including the lower elevations at the South Entrance and along the rim. Stellar’s Jays were observed primarily at Park Headquarters and roadside areas near Godfrey Glen and the Goodbye Picnic area. No scrub jays were observed at CLNP by our team, although they do occur in the park, particularly in the open lower elevation habitats. Another corvid, the Common Raven, was also observed in picnic areas, near Park Headquarters, and in parking areas along the rim. As was expected, bird densities were highest and birds were most active near picnic sites. All corvid species are attracted to activities that include food. Gray Jays, as noted many times by others, were particularly aggressive and we fed a few of them by hand at the Annie Creek picnic area near the South Entrance.

Interactions between species were not directly observed. Several species overlapped at some sites (especially the Park headquarters area), but we did not observe aggressive encounters between species. We did observe some aggressive interactions between Stellar’s Jays in the Goodbye Picnic Area.

This study was done to educate a small group of undergraduate students at the Oregon Institute of Technology on some field techniques for ethological observation and to demonstrate zonation amongst related species of birds. It also served as a preliminary (pilot) study for potential longer term research on corvid territoriality and for use in biology field trips taught by the principal investigator. The findings were of a preliminary observational nature and were not intended for publication or to add to specific knowledge of bird ethology. The studies and observations did indicate, however, some of the problems and possible approaches to conducting this type of study at CLNP.

For this study, were one or more specimens collected and removed from the park but not destroyed during analyses? No

Funding provided this reporting year by NPS: 0

Funding provided this reporting year by other sources: 0

Full name of college or university:  n/a

Annual funding provided by NPS to university or college this reporting year: 0


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