De. Chamberlain et Rd. Gregory, Coarse and fine scale habitat associations of breeding Skylarks Alauda arvensis in the UK, BIRD STUDY, 46, 1999, pp. 34-47
The occurrence of breeding Skylarks, in terms of both density and presence/
absence, was assessed from Breeding Bird,Survey data irt relation to habita
t in a random sample of about 1500 1-km squares throughout the UK in two co
nsecutive years, with particular emphasis on the farmland habitat. Upland g
rassland and other seminatural grassland habitats held the highest mean den
sities of Skylarks. Within farmland, arable land held the highest and pastu
re land the lowest densities, bur there was a seasonal decline in arable de
nsity. Regression analyses showed that Skylark occurrence was most consiste
ntly related to the area of arable farmland (positive effects) and the area
of woodland (negative effects). Skylark density increased with increasing
habitat diversify in upland squares only. Within farmland, boundary charact
eristics and the presence of grazers had the most consistent negative effec
ts. The diversity of field types was positively related to Skylark density,
which gives some support to the hypothesis that a decrease in the diversit
y of field types as a result of simplification of farm rotations in recent
decades may have led to the decline of the Skylark in the UK, but further c
onclusions about the effects of specific crop types were not possible at th
is scale of analysis.