Functional Ecology 17, 590-597 (2003)
Parental foraging effort and offspring growth in Adelie penguins: does working hard improve reproductive success?
Takahashi A, Y Watanuki, K Sato, A Kato, N Arai, J Nishikawa, Y Naito.
1. Studying variability of parental foraging and provisioning behaviour in relation to
reproductive success is fundamental to improving understanding of regulation of
reproductive effort in animals. The hypothesis that parents with higher foraging effort
have higher offspring growth rates was tested in chick-provisioning Ad¨Ślie Penguins in
Antarctica over five consecutive years.
2. Time spent diving per day, an index of foraging effort, varied among male and
female parents, and among pairs. These daily interindividual or interpair differences in
time spent diving appeared to be consistent over the 2-week study period within each
breeding season.
3. Frequency of meals delivered by parents was positively correlated with their brood
growth rate. Meal frequency was, however, independent of the amount of time spent
diving per day by parents and the time spent diving did not affect brood growth rates.
4. Rates of body mass loss of breeding pairs were positively correlated with brood
growth rates.
5. Our results did not support the hypothesis that parents with higher foraging effort
have higher offspring growth rates. It is suggested that parental allocation of resources
obtained during foraging, rather than the degree of foraging effort, is the more important
process determining offspring growth rates in Ad¨Ślie Penguins.
PG03-3
|
