A critical analysis of ‘false-feeding’ behavior in a cooperatively breeding bird: disturbance effects,satiated nestlings or deception? |
| |
Authors: | Paul G McDonald Anahita J N Kazem Jonathan Wright |
| |
Institution: | (1) School of Biological Sciences, University of Wales, Bangor, Gwynedd, LL57 2UW, United Kingdom;(2) Department of Zoology, La Trobe University, Bundoora, 3086, Australia;(3) Institute of Biology, NTNU, Trondheim, 7491, Norway;(4) Centre for the Integrative Study of Animal Behaviour, Macquarie University, Sydney, 2109, Australia |
| |
Abstract: | ‘False feeding,’ where helpers arrive at nests with food but fail to provision the young, has been reported in several cooperative
species. This and other potentially ‘deceptive’ behavior has been interpreted as indicating that helping may operate as a
signal within such social groups. We critically examine these phenomena in the provisioning behavior of the bell miner Manorina melanophrys. Excessively close observation distances can artificially elevate the rate of false feeding in this (and other) species,
but once this had been accounted for, there was little evidence for any ‘deceptive’ behavior by helpers or breeders. Natural
and experimentally induced variation in the presence of a potential conspecific audience at the nest did not have any consistent
influence upon the rate of false feeds, which was low at 7.94% of 6,880 nest visits. Instead, encountering unexpectedly low
levels of brood demand provided a more parsimonious explanation for those visits where helpers failed to feed nestlings or
ate the food themselves. Failure to completely transfer a load to nestlings was more likely when the load contained a high
proportion of sticky lerp, indicating a simple prey-transfer problem. Finally, individuals that arrived at nests without prey
were often members of neighboring breeding pairs, suggesting that these few non-feeding visits may instead involve an information-gathering
function. We, therefore, suggest that future studies explicitly exclude the possibility of observer disturbance and all aspects of normal provisioning behavior before applying the terms ‘false feeding’ or ‘deceptive’ and inferring anything more
than straightforward helping at the nest. |
| |
Keywords: | Bell miner White-winged chough Carrion crow Helping at the nest Signaling hypotheses |
本文献已被 SpringerLink 等数据库收录! |
|