Comparing Methods for Monitoring Nest Attendance in Ancient Murrelets

Abstract

Abstract. Knock-down tags are often used to monitor population and nest attendance patterns of burrow-nesting seabirds. However, the accuracy of the knock-down method has not been considered in detail. Here, measurements of nest attendance patterns for Ancient Murrelets (Synthliboramphus antiquus) obtained by the knock-down and the radio telemetry methods were compared on a colony at Reef Island, Haida Gwaii, Canada. Radio transmitters and knock-down tags both indicated activity 79% of the time (range: 61–96%, N = 307), and the correlation between the two methods was significant. Hence, knock-down tags provide information that, although coarse, can provide an adequate indication of reproductive behavior in Ancient Murrelets without disturbance to the bird.