Tiny prey for a tiny owl

Studying nesting diet of Northern Saw-whet Owls in Alberta

Abstract

Northern Saw-whet Owls, Aegolius acadicus, are small boreal owls that thrive in mature forest ecosystems, utilizing abandoned tree cavities or man-made boxes for nesting. Pellet pads were collected from such nest boxes placed by the Beaverhill Bird Observatory between Tofield, AB and Miller, AB. They contain valuable information on the quality and quantity of food brought back to the nest. Taken from years 2005 and 2007, thirteen pellet pads from thirteen different nest boxes have been investigated to find, identify, and quantify 876 prey individuals. Each nest box contained a minimum of 41±34 prey individuals, almost all distributed between three ecologically distinct mammal groups: voles, mice, and shrews. Voles were the most plentiful and the most common species identified was the Meadow Vole, Microtus Pennsylvanicus. This data is a subset of a larger study that can be used by a variety of biologists and policy makers to further understand and protect this ecological relationship and the environment it relies upon.

Discipline: Biology

Faculty Mentor: Mark Degner , Gordon Youzwyshyn