Movement and mortality of British-ringed skylarks alauda arvensis

Abstract

The national archive of recoveries of British-ringed Skylarks to 31 December 1992 (n = 201 birds) was analysed in terms of distances and directions of movement, and mortality factors. In the British Isles, the species is rather sedentary compared with elsewhere in Europe, with only nine overseas recoveries; and two-thirds of recoveries were within 10 km of the ringing site. There is no evidence of post-juvenile dispersal from ringing returns. A general trend in movements was apparent from north and east to south and west in autumn, and vice versa in spring. Intra-seasonal movements evident from ringing support field observations of cold-weather migration. Most birds (88%) were recovered within five years of ringing although some survived to 10 years of age. Most reported deaths for juveniles are in June and July; and in May and June and from January to March for fully-grown birds. The main causes of mortality identified were predation by domestic cats, raptors or owls, and collision with road traffic. Results are discussed in relation to Skylark movements on the continent, and the movements and mortality factors of two other British partial migrants, Pied Wagtail and Grey Wagtail. © 1996 British Trust for Ornithology.