Raptors: A Field Guide to Survey and Monitoring

3.3 Evidence adult Age days barn owl behaviour Bijlsma birds of prey breeding attempt breeding pairs breeding season Britain and Ireland brood chicks clutch common buzzard crags Cramp & Simmons density display disturbance estimate eyrie faecal droppings feeding female fieldworkers fledged young golden eagle goshawk habitat hatching health and safety hen harrier honey-buzzard immature incubation individual kestrels Late April late June leave the nest licence Locating active nests long-eared owls male marsh harriers measurements merlins Mikkola Montagu's harriers moulted feathers nest sites nest visits nesting area nesting range nesting territory Newton Northern Ireland observations occupied nesting ospreys pellets peregrine population raptor raptor species Raptor Study Groups Ratcliffe raven red kites Republic of Ireland ringing RSPB Schedule Scotland Scottish searching Section short-eared owls Signs of occupancy sparrowhawk species accounts study area suitable survey tags tarsus tawny owls vantage point white-tailed eagles wing length winter woodland