M. Bolton, EXPERIMENTAL-EVIDENCE FOR REGULATION OF FOOD DELIVERY TO STORM-PETREL, HYDROBATES PELAGICUS, NESTLINGS - THE ROLE OF CHICK BODY CONDITION, Animal behaviour, 50, 1995, pp. 231-236
The existence of a possible feedback mechanism, causally relating the
nutritional status of nestling British storm petrels to the subsequent
rates of food provisioning by their parents, was examined using a sup
plementary feeding experiment. There were no differences in parental p
rovisioning behaviour between experimental and control groups before t
he supplementary feeding regime commenced. Thereafter, chicks receivin
g supplementary food showed higher levels of body condition (attributa
ble to the experimental protocol), and consequently received smaller a
nd less frequent meals from their parents than controls. The total amo
unt of food received by the experimental group (parental delivery plus
supplementary food) was similar to the amount delivered by control pa
rents, indicating compensatory regulation of provisioning. These resul
ts support earlier findings at the same colony but are in contrast to
similar studies on other procellariiform species elsewhere. The demons
tration of regulation of food delivery casts doubt on hypotheses relat
ing slow growth and lipid accumulation of procellariiform nestlings to
scarce and unpredictable food resources, and indicates that more rece
nt explanations relating lipid deposition to chronic overprovisioning
by the adults are untenable for this species. (C) 1995 The Association
for the Study of Animal Behaviour