You are what you eat: stable isotope ecology of owl diets in Alberta, Canada

Abstract

Stable isotope ratio analysis (SIRA) was used to analyze the trophic level of the diets of three owl species: Barred Owl (Strix varia), Northern Hawk Owl (Surnia ulula) and Great Horned Owl (Bubo virginianus). Barred Owl and Northern Hawk Owl had diets from a similar trophic level. Both the Barred Owl and Northern Hawk Owl had diets from trophic levels that differed significantly from that of the Great Horned Owl. Great Horned Owl had the most diverse isotope ratios indicating the greatest intraspecific variation in diets of the three species of owls. Results of SIRA can help with the determination of owl diets when used in conjunction with traditional methods of studying diet, but they can also stand alone as indicators of unique diet habits or discerning the trophic level of the diets of museum specimens.

Parent Publication

• Biology and conservation of owls of the Northern Hemisphere: 2nd International symposium

Citation

Duxbury, James M.; Holroyd, Geoffery L. 1997. You are what you eat: stable isotope ecology of owl diets in Alberta, Canada. 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. 148-154.