RESPONSES OF RED- SHOULDERED HAWKS (BUTEO LINEATUS) TO
TAPE-RECORDED BROADCASTS

Terry Balding
Biology Department, University of Wisconsin-Eau Claire, Eau Claire, Wisconsin
54702

Conspecific tape-recorded calls (N=460) were used from 1986-1996 to evoke
150 responses of the red-shouldered hawk (Buteo lineatus).  The objectives of
this study were to determine the effect of decibel (db) level on evoking
responses, response rate, the  farthest distance from a tape-recorded broadcast
that a nesting red-shouldered hawk would respond, and whether more
red-shouldered hawks would respond during the courtship or nestling stage.  For
all years, a greater number of red-shouldered hawks responded to a 130 db
tape-recorded call (49 of 159) than to a 95  db call (9 of 168).  Response rate 400
m from a known nest was 70.9%.  The farthest distance from the nest which a
bird responded to a 130 db tape-recorded call was approximately 1600 m from
the speaker.  There was no significant difference in the number of red-shouldered
hawks responding to 130 db tape-recorded calls between the courtship and
nestling stages.  Results suggest that a 130 db tape-recorded call could be used to
increase the number of red-shouldered hawks responding and that calling stations
should be 800 m apart along a transect.

Keywords:  Red-Shouldered Hawk, Buteo lineatus, broadcast calls, tape-recorded


Terry Balding
Biology Department            
University of Wisconsin-Eau Claire
Eau Claire, Wisconsin 54702  USA

Phone:  715-8364415
Fax:  715-8365089
Email:  BaldinTA@UWEC.edu
Platform - yes,  Poster - No.