Importance of prairie wetlands and avian prey to breeding Great Horned Owls (Bubo virginianus) in Northwestern North Dakota

Abstract

Prey use by Great Horned Owls (Bubo virginianus) is documented widely in North America, but not in the vast northern Great Plains. During spring through early summer 1986-1987, I recorded 2,900 prey items at 22 Great Horned Owl nesting areas in the prairie pothole farm- and rangelands of northwestern North Dakota. The owls relied heavily on wetland-dependent prey species (overall, 57 percent by number and 76 percent biomass) especially ducks (Anserinae) and rails (Rallidae). Far more avian (65 percent by number and 84 percent biomass) and less mammalian prey were used than typically reported. Variation in diet composition among owl families was not explained well by nesting area habitat, and was dominated by prey from wetlands regardless of wetland habitat availability.

Parent Publication

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

Citation

Murphy, Richard K. 1997. Importance of prairie wetlands and avian prey to breeding Great Horned Owls (Bubo virginianus) in Northwestern North Dakota. 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. 286-298.