AVIS-IBIS

Birds of Indian Subcontinent

Producers and scroungers: A general model and its application to captive flocks of house sparrows

Publication Type:Journal Article
Year of Publication:1981
Authors:Barnard, CJ, Sibly, RM
Journal:Animal Behaviour
Volume:29
Issue:2
Date Published:1981
ISBN Number:0003-3472
Keywords:Passer, Passer domesticus, Passeridae
Abstract:Many forms of interaction within and between species appear to be based on [`]scrounger' individuals or species exploiting a limited resource provided [`]producers'. A mathematical model is presented which shows whether or not scroungers are maintained in a group, depending on their frequency and the group size. Some of the predictions of the model were tested in captive flocks of house sparrows Passer domesticus L. Here the scroungers obtained most of their food (mealworms) by interaction and the producers found most of their food by actively foraging: the pay-off to each type was measured as mealworm capture rate. Neither type changed strategy opportunistically in response to instantaneous flock composition but, not surprisingly, scroungers fared better when one of more producers were present. However, scrougers did much worse than expected when greatly outnumbered by producers, perhaps because producers then found the available food very quickly.
URL:http://www.sciencedirect.com/science/article/pii/S0003347281801170
Short Title:Animal Behaviour
Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith