Owl broadcast surveys in the Foothills Model Forest, Alberta, Canada

Abstract

Broadcast surveys are used to determine the presence and relative abundance of nocturnal owls, but there has been little effort to standardize such surveys. This paper examines broadcast survey data collected in 1995 and 1996 in the Foothills Model Forest, Alberta, Canada. Three hundred calls from six species of owls were recorded at 893 stops for a call rate of 0.34 calls per stop. Moon phase significantly affected the rate of owls calls. Owl call rate was significantly lower in the middle of the night (midnight to 3:59) compared to the early night (20:00 to 23:59) and early morning (4:00 to 7:59). During precipitation and strong wind, fewer owls called spontaneously or responded to the playback calls. Call rate of owls also declined with temperature. Owls called significantly more frequently during the 2 minute listening period beginning each 15 minute survey period than in subsequent listening periods after playback. Four behavioral responses to playback were recorded: calling and approaching, silently approaching and calling, silently approaching and not calling, and calling but not approaching.

Parent Publication

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

Citation

Takats, D. Lisa; Holroyd, Geoffrey L. 1997. Owl broadcast surveys in the Foothills Model Forest, 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. 421-431.