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Abstract
If low reproductive output plays an important role in the population decline of the Burrowing Owl (
Speotyto cunicularia,) in Canada, we predicted the decline would slow or stop in our study population after consecutive years of productivity enhancement via food supplementation and predator exclusion. In the portion of our study site for which historical data existed, the yearly rate of decline averaged 24.7 percent per year before, and 11.8 percent per year after, productivity enhancement. Our overall study population showed no decline after the first year of treatment, but declined 17 percent following the second year of treatment. Females (both adults and juveniles) showed lower site fidelity and dispersed farther than did males, and juveniles showed lower site fidelity and dispersed farther than did adults. Although adult dispersal distances were small, natal dispersal distances suggest that emigration probably occurs from our study area, increasing the difficulty of detecting a population effect from our treatment.
Parent Publication
Citation
Wellicome, Troy I.; Holroyd, Geoffrey L.; Scalise, Karyn; Wiltse, Earl R. 1997. The effects of predator exclusion and food supplementation on Burrowing Owl (
Speotyto cunicularia) population change in Saskatchewan. In: Duncan, James R.; Johnson, David H.; Nicholls, Thomas H., eds. Biology and conservation of owls of the Northern Hemisphere: 2nd International symposium. Gen. Tech. Rep. NC-190. St. Paul, MN: U.S. Dept. of Agriculture, Forest Service, North Central Forest Experiment Station. 487-497.
