Behavior of radio-tracked Common Cuckoo females during the breeding season in Japan

Abstract

The breeding behavior of Common Cuckoo Cuculus canorus females was studied in detail by individual marking, radio-tracking, and automatic recording of radio signals. A total of 132 female cuckoos was captured, and radio transmitters were attached to 44 of them. The female cuckoos parasitised three different types of hosts: Azure-winged Magpies Cynopica cyane, Great Reed Warbler Acrocephalus arundinaceus and Bull-headed Shrike Lanius bucephalus. Female cuckoos using magpie hosts were radio-tracked for a total of 131.1 hours, and females using warbler hosts were radio-tracked for a total of 142.1 hours. The total time for cuckoos using shrike hosts was 12.6 hours. Female cuckoos were found to have distinct breeding and feeding areas, which they commuted between every day. Dominant females maintained strict breeding site tenacity throughout the breeding season. Each female specialized on one host type, knew almost all of the host nests in their breeding areas, and laid eggs selectively among the nests. The reasons for commuting between breeding areas and feeding areas, and the existence of a dominance hierarchy among female cuckoos are discussed.