Sc. Whitehead et al., WINTER FIELD USE BY THE EUROPEAN STARLING STURNUS-VULGARIS - HABITAT PREFERENCES AND THE AVAILABILITY OF PREY, Journal of avian biology, 26(3), 1995, pp. 193-202
A regular census of an Oxfordshire farm, U.K., showed that the residen
t Starlings Sturnus vulgaris preferred to feed in established pasture
fields. Fields which were closer to the daytime roost, provided feedin
g areas further from hedges, and had shorter swards were particularly
preferred. The Starlings' habitat preferences could also be explained
in terms of the availability of prey. This was quantified via the fora
ging behaviour of individual birds allowed to forage in small enclosur
es in a sub-sample of the fields available to the flock. The experimen
tal birds' prey capture rates in each of the fields were significantly
correlated with the observed flock foraging densities. This was a pre
y-specific effect: although the birds could have obtained a higher ene
rgy intake rate by feeding on earthworms in less preferred fields, the
Starlings were seen to feed in those fields which allowed them to max
imise the amount of energy obtainable from leatherjackets. A laborator
y prey choice experiment demonstrated that this field preference could
be attributed to an absolute preference for leatherjackets over earth
worms.