Publication Type: | Journal Article |
Year of Publication: | 1994 |
Authors: | Bennun, L |
Journal: | Animal Behaviour |
Volume: | 47 |
Issue: | 5 |
Date Published: | 1994 |
ISBN Number: | 0003-3472 |
Keywords: | Passeridae, Pseudonigrita, Pseudonigrita arnaudi |
Abstract: | Abstract. Data from feeding watches at nests of communally breeding grey-capped social weavers were used to examine the factors influencing feeding visit frequencies, food item size and the rate of food supply to the nestlings (feeding rate). Provisioning was not affected by environmental factors (time of day, temperature, rainfall, date and year) but nestling age, brood size and the number of birds feeding at the nest all had substantial effects. Having accounted for brood size and nestling age, feeding visit frequency and feeding rate increased when more birds fed, although the mean size of food items declined. The contribution of a single helper significantly increased the feeding rate (corrected for other effects) both within and across nesting attempts, with mean increases of 20% and 7%, respectively. Helpers fed less frequently than the breeding birds but brought items of a similar size. Breeders did not reduce their feeding effort when helped. Helpers were recorded more often in the later part of the nestling period, when nestling food demands were highest. Paired and unpaired helpers made similar contributions, but paired helpers assisted only when they had no young to feed in their own nests. Higher nestling survival and rates of weight increase in nests with helpers seem likely to be a consequence of the extra food supplied. |
URL: | http://www.sciencedirect.com/science/article/pii/S0003347284711432 |
Short Title: | Animal Behaviour |
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