| Publication Type: | Journal Article |
| Year of Publication: | 1992 |
| Authors: | Klomp, NI, Furness, RW |
| Journal: | Colonial Waterbirds |
| Volume: | 15 |
| Issue: | 1 |
| Date Published: | 1992 |
| ISBN Number: | 07386028 |
| Keywords: | Calonectris, Calonectris borealis, Calonectris diomedea, Procellariidae, Procellariiformes |
| Abstract: | We determined meal size frequency and timing of chick feeding by Cory's Shearwaters at a colony in the Azores by weighing chicks every 4 h. Chicks were fed mainly on fish, but occasionally on cephalopods. Meal sizes delivered to the chicks averaged 60 g (S.D. = 32.2 g). Overnight positive mass increments ranged up to 180 g. Inter-feed mass loss due to respiration and excretion was positively correlated with the chicks' initial masses. The minimum amount of food required by the chicks to maintain constant mass (44.2 g day-1) was well surpassed by actual meal sizes received. The mean growth rate of the chicks (24.8 g day-1) also suggest the presence of a plentiful and nutritious food supply available to the colony. Most feeds were between 2000 h and 0400 h (GMT). The timing of adult returns was, however, dependent on ambient light conditions. Birds fed their chicks less on moonlit nights and tended to return to nests later. This response to variations in nocturnal illumination is in remarkable contrast to the diurnal return of birds of the same species at Selvagem Grande, 1400 km distant. The effects of ambient light on food provisioning behavior may be related to nocturnal food availability rather than predator avoidance by adult birds. Comparisons are made with chick-feeding patterns of other pelagic Procellariiformes. |
| URL: | http://www.jstor.org/stable/1521358 |
| Short Title: | Colonial Waterbirds |
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