Journal ArticleDOI
American robin nestlings compete by jockeying for position
TLDR
It is concluded that jockeying for position by Nestling American robins can influence the pattern of food allocation by parents, and that hungry nestlings can improve their competitive standing against nestmates by moving to positions where parents are more likely to feed them.Abstract:
We investigated whether nestling American robins (Turdus migratorius) were capable of influencing food distribution in their nests by perceiving that certain sectors of the nest received a relatively high proportion of feedings and positioning themselves accordingly. Feeding observations were obtained from videotape recordings taken at different stages of the nestling period. Parents generally arrived at a predictable location on the nest rim and allocated proportionally more food to nestlings in the central position. The degree of nestling movement was significantly positively correlated with variation in the predictability of parental arrival locations on the nest rim. Furthermore, nestlings moved more in broods suffering brood reduction. This suggests that when competition for food is intense and the location of parental arrival is predictable, nestlings respond by jockeying for access to the most favorable (i.e., central) position in the nest. We conclude that jockeying for position by nestlings can influence the pattern of food allocation by parents, and that hungry nestlings can improve their competitive standing against nestmates by moving to positions where parents are more likely to feed them.read more
Citations
More filters
Journal ArticleDOI
Maternal testosterone in the avian egg enhances postnatal growth
TL;DR: Injections of testosterone into the yolk of unincubated eggs enhanced the growth after hatching compared to nestlings that had hatched simultaneously from control eggs, but more testosterone did not compensate for reduced growth that was caused by later hatching due to asynchronous incubation of clutches.
Journal ArticleDOI
Begging the question: are offspring solicitation behaviours signals of need?
TL;DR: Empirical support is assessed for the recent theory that begging advertises offspring need, that parents provision young in relation to begging intensity, and that the apparently costly nature of begging ensures the reliability of the signal.
Journal ArticleDOI
Evolutionary theory of parent-offspring conflict
TL;DR: A recent shift in emphasis from models that define the possible extent of conflict to those that predict its resolution offers greater hope of a testable theory of parentoffspring conflict.
Book ChapterDOI
Hatching Asynchrony and the Onset of Incubation in Birds, Revisited
TL;DR: In most animals, offspring from a reproductive bout usually hatch, emerge, or are born within a relatively short time of each other compared to the time required for their development, so hatching or birthing in most animals is synchronous.
Journal ArticleDOI
When do Canary Parents Respond to Nestling Signals of Need
TL;DR: It is suggested that the broad food distribution patterns of the parents are influenced by size-dependent chick behaviours, such as proximity to the parent, which respond to short-term fluctuations in chick hunger as signalled by the posturing and calling behaviours of the chick.
References
More filters
Journal ArticleDOI
Analyzing tables of statistical tests
TL;DR: Technique non parametrique pour la signification statistique de tables de tests utilisees dans les etudes sur l'evolution notamment.
Journal ArticleDOI
Parent-Offspring Conflict
TL;DR: In this paper, the parent-offspring conflict in sexually reproducing species is viewed from the standpoint of the offspring as well as the parent, and it is shown that conflict is an expected feature of such relations.
Book
The evolution of parental care
TL;DR: This paper examined the evolution of variation in egg and neonate size, of viviparity and other forms of bearing, and of differences in the duration of incubation, gestation, and lactation.