Sandra Irwin, Mark W. Wilson, Thomas C. Kelly, Barry O¿Mahony, Geoff Oliver, Paul Troake, Barry Ryan, Chris Cullen, Barry O¿Donoghue, John O¿Halloran

2011

Unknown

Irish Birds

The breeding biology of Hen Harriers Circus cyaneus in Ireland over a five year period

Published

()

165

172

The breeding biology of Hen Harriers Circus cyaneus was investigated between 2007 and 2011 in three study areas in Ireland. The aim of this study was to provide an understanding of the breeding ecology of Hen Harriers in order to informconservation and land use planning. The number of pairs of breeding Hen Harriers in each of three study areas declined between 2007 and 2011. Nest success and fledged brood sizes were similar across study sites and did not show consistent trends during this period, except in West Clare where success rate of nests decreased. Breeding productivity over the course of the study was low, but was sufficient to allow Hen Harrier populations in these areas to remain stable, provided that juvenile survival and recruitment to the breeding population was sufficiently high. The number of young fledged at successful Hen Harrier nests in this study was, however, quite low relative to other populations. An understanding of basic biology is essential to the development of effective conservation strategies, including those centred on habitat management.