A sightability model for moose developed from helicopter surveys in western Wyoming

Authors(s): C. R. Anderson, Jr.

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Publication Date: 0000-00-00

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Abstract: I conducted helicopter surveys of radiocollared moose (Alces alces) to determine factors that influence moose sightability from the air and to develop a predictive model for future surveys. Variables measured were time of day, sex/age composition of groups, % vegetative cover and vegetative cover type, % snow cover, topography, moose activity, light intensity, group size, perpendicular distance to the group, study area, and primary observer. I determined significant variables using logistic regression analyses. Multivariate analyses indicated that % vegetative cover was the only variable influencing sightability. Further analyses, however, suggested an interaction between group size and topography may also be important. My final model selection was based on compromises between group size and topography may also be important. My final model selection was based on compromises between statistical significance and biological interpretation. I selected the model that included only % vegetative cover over the more complicated models. The model correctly classified 83% of 104 observations. Estimator precision is best maintained when moose are using open cover types (<=50% vegetative cover).

Keywords: animal, mammal, ungulate, moose, Alces alces, Cervidae, radio collar, habitat, population, Wyoming Cooperative Fish and Wildlife Research Unit, University of Wyoming