Background:
Information has been lacking in existing land and wildlife management plans and some populations of burrowing owls have declined and others extirpated throughout North America. The U.S. Fish and Wildlife Service listed the western subspecies as a Species at Risk. Burrowing Owl populations vary in degree to which they migrate, and there is concern that human-induced changes to over-wintering areas in Mexico are the cause of the observed declines. By comparing demographic parameters of migratory populations to that of resident populations, we may begin to understand the underlying causes of decline. Thus, several state agencies and cooperative research units are working to develop a coordinated research program to compare populations across multiple spatial scales. The purpose of this project is to provide information on the life history and habitat use of burrowing owls to the Western Working Group on Burrowing Owls, the U.S. Fish and Wildlife Service status review committee, and Pima County Board of Supervisors for incorporation into the Pima County Habitat Conservation Plan.

Location:
Tucson Basin of southern Arizona

Approach:
We will capture owls using proven trapping methods, fit owls with backpack style radio transmitters that are less than 4% of body weight, track owls using radio receivers, measure habitat characteristics used by owl, measure landscape characteristics at nest burrows, and calculate size of dispersal ranges. The nesting status of all known nest burrows within the Tucson Basin will be monitored.

Benefits:
We currently lack the ability to estimate annual fecundity, natal recruitment, juvenile survival, and adult survival of Burrowing Owls within the Southwest and to compare these results with other study areas within the western Unites States, should enable us identify the underlying causes of decline. As a result, existing land use and wildlife management plans fail to adequately incorporate the needs of this species in their plans. Results of this study, especially the delineation of dispersal corridors, will be readily available to Pima County for incorporation into their Habitat Conservation Plan. Results of this study will also be incorporated into the U.S. Air Force's natural resource management plan.

For more information contact:
Renee Wilcox, Arizona Game and Fish Department, 5000 W. Carefree Highway Phoenix, AZ 85086-5000 .
Phone: (520) 742-1911 E-mail: rwilcox@gf.state.az.us


Michael Ingraldi, Ph.D., Arizona Game and Fish Department, 5000 W. Carefree Highway Phoenix, AZ 85086-5000 .
Phone: (928) 523-5625 E-mail: mingraldi@cybertrails.com