DEVELOPMENT OF A HABITAT SUITABILITY INDEX MODEL FOR BURROWING OWLS IN THE EASTERN CANADIAN PRAIRIES

Recent efforts to sustain Burrowing Owl (Athene cunicularia) populations in Manitoba have been unsuccessful, and the species is now effectively extirpated from the province. Although specific causes of the decline remain unknown, loss, fragmentation, and degradation of suitable habitat have likely been major contributors to this decline. We developed a habitat suitability index model to determine suitability of Burrowing Owl nesting habitat in southwestern Manitoba and southeastern Saskatchewan. Model parameters were obtained using a modified Delphi technique to solicit expert opinions. An interactive, adaptive learning approach was used in model development, iteratively refining the model until acceptable levels of accuracy and robustness were achieved. Application of the model to historical Burrowring Owl breeding sites in Manitoba indicated that habitat suitability is often reduced by the presence of tall vegetation at former nest burrows. A management approach involving moderate grazing to maintain low vegetation height at all nest burrow sites is recommended.