Status of the Hen Harrier Circus cyaneus in the UK and the Isle of Man in 1998

A survey of breeding Hen Harriers in the UK raid the Isle of Mail carried o ut in 1998 consisted of two parts: a complete census of 10-km squares at th e core of the species' known range, and a random sample of 10-km squares ac ross the rest of its known recent range. Front this, the UK and Isle of Mal l breeding population was estimated art 570 territorial pairs: 436 in Scotl and, 19 in England, 28 in Wales, 38 in Northern Ireland and 49 on the Isle of Mail. Although there was no overall change in the size of the UK and Isl e of Man population between 1988-94 and 1998, numbers declined in Orkney an d increased in Northern Ireland. In Scotland, numbers increased on grouse m oors and decreased ill young plantation between 1988-89 and 1998, so that 5 5% of the population is now found on grouse moor. A similar situation exist s in England, but in Northern Ireland 45% of the population was found breed ing in open wrens within mature conifer plantations in 1998.