Scottish Raptor Groups

For most of the 20th century the Kestrel enjoyed the status of being the commonest bird of prey in Scotland. A bird of the open countryside its characteristic hovering and perch hunting techniques makes it a highly visible raptor, while its habit of nesting in unusual urban locations has given it a high media profile. Although there has been no national survey, the current estimate of the Scottish population is 7,765 pairs, 21% of the UK population (36,800). The recent phenomenal Buzzard expansion and the stabilisation of the Sparrowhawk have relegated the Kestrel to third spot in terms of breeding pairs in Scotland .

The Kestrel is classed as being in moderate decline, numbers having fallen probably due to a combination of a reduction in suitable habitat for small mammals, its main prey item, and increased competition from other raptors as they have recovered from the low population levels in the second half of the 20th century.

Although very catholic in its prey range, the short tailed field vole is the preferred diet and in upland grassland both territory occupation and breeding performance are closely tied in to the three year cycles of this small mammal. In peak vole years Kestrel territory occupation is high, clutch sizes large and brood survival high. When the vole numbers bottom out after the peak the Kestrel occupation and productivity also falls.

The Kestrel's breeding strategy is based upon a quick turnover of the population, compensating for a high mortality rate (up to 60% of juveniles die in their first winter) with clutch sizes of 4 to 6 and good brood survival. They are partial migrants, young birds from Scotland moving south after dispersal from family groups to winter in southern England and northern Europe.

The Kestrel is not in danger as a species but the situation does need to be carefully monitored. In its favour the Kestrel's lifestyle - mobile, able to feed on a range of prey, takes readily to nest boxes and a variety of sites and a high productivity rate - means it has the potential to bounce back quickly from adversity.

Gordon Riddle

Village, A. 1990 The Kestrel, T&AD Poyser, London

Riddle, G. 1992 Seasons with the Kestrel, Blandford, London

Shrubb, M. 1993 The Kestrel, Hamlyn Species Guides, London

Website: http://www.riddle-kestrel.com/