Monitoring Between-Year Movements and Assessment of Artificial Burrow Feastures Useful in Conservation and Management of Burrowing Owls, 1997 Annual Report.

摘要

One essential component of endangered species management is to understand the requirements to successfully reproduce for each species. In the case of western burrowing owls, which for all intents and purposes can be considered to be secondary cavity nesters because they cannot dig their own burrows, this means understanding their requirements for underground burrow systems used for nesting and roosting. While information on the above ground features of burrowing owl nest sites is available in the literature (e.g., Rich 1986, Plumpton and Lutz 1993), there is virtually no information on the below-ground features of burrows important to nesting owls. Our objectives in this study were to (1) continue color-banding burrowing owls to monitor return rates to the study area, site and burrow fidelity, and between-year movements (i.e., breeding and natal dispersal) by adults and young, and (2) examine nest-site preferences in two field experiments using artificial burrows. Specifically, we wanted to examine effects of underground chamber size and tunnel diameter on choice of nesting site and productivity of owl pairs. This report summarizes activities during the spring and summer of 1997.