Upper Midwest Environmental Sciences Center
Radio telemetry documents 24-hour feeding activity of wintering lesser scaup
Custer, C. M., Custer, T. W., and Sparks, D. W., 1996, Radio telemetry documents 24-hour feeding activity of wintering lesser scaup: Wilson Bulletin, v. 108, no. 3, p. 556-566.
We used radio telemetry to record 198 h of feeding behavior of five Lesser Scaup (Aythya affinis) on the Indiana Harbor Canal in northwestern Indiana during January and February 1994. Lesser Scaup fed for short periods of time intermittently during each 24-h period. Lesser Scaup fed a total of 96 min during the day and 226 min during the night. They fed more between sunset and midnight (31.9% of the period, P = 0.003) than between sunrise and noon (11.6%) or noon and sunset (19.5%); time spent feeding between midnight and sunrise (26.3%) did not differ from other times of day. Mean dive duration (22.9 +/- 0.64 sec) did not vary by time of day (P = 0.186-0.744). These results are the first 24-h feeding activity reported for individually marked Lesser Scaup.
Keywords: Activity budgets, diving ducks, canvasbacks, behavior