Birds of Indian Subcontinent

Crop size as an index of chick provisioning in the Greater Flamingo Phoenicopterus roseus

Publication Type:Journal Article
Year of Publication:2012
Authors:Rendón, MA, Garrido, A, GUERRERO, JOSÉC, Rendón-Martos, M, Amat, JA
Date Published:2012
ISBN Number:1474-919X
Keywords:body condition, Digestion rate, feeding frequency, meal size, mixed models, Phoenicopteridae, Phoenicopterus, Phoenicopterus roseus, Phoenicopterus ruber, Phoenicopterus ruber roseus
Abstract:After being fed by their parents, Greater Flamingo chicks store food in their crops, which protrude outwards. We allocated the crop profiles of chicks to four categories to assess the relationship between body mass and crop profile variation, and so determine whether crop size can be used as an accurate index of the amount of food ingested, and to determine the timing and frequency of provisioning. We registered changes in body mass and crop fullness in eight chicks captured with turgid crops and kept in captivity until constant mass was achieved. The meal mass ingested by the chicks during each parental feeding was around 18% of net chick mass and varied greatly with crop profile. Mean transition times between the four crop profile categories ranged from 6 to 14 h. Between 1998 and 2009, 34% of chicks caught for ringing in a breeding colony had empty crops. From crop profiles recorded during the handling of chicks, it was estimated that approximately one-third of the chicks were fed in the evening and another third during the night. Our results have implications for the estimation of body condition indexes because body mass should be free of the influence of the mass of the food in the crop.
Short Title:Ibis
Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith