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Rendon M.A.,CSIC - Donana Biological Station | Garrido A.,Programa de Actuaciones de Aves Acuaticas en Andalucia | Rendon-Martos M.,Reserva Natural Laguna de Fuente de Piedra | Ramirez J.M.,Programa de Actuaciones de Aves Acuaticas en Andalucia | Amat J.A.,CSIC - Donana Biological Station
Journal of Animal Ecology | Year: 2014

Summary: In sexually dimorphic species, the parental effort of the smaller sex may be reduced due to competitive exclusion in the feeding areas by the larger sex or physiological constraints. However, to determine gender effects on provisioning patterns, other intrinsic and extrinsic factors affecting parental effort should be accounted for. Greater flamingos (Phoenicopterus roseus) exhibit sexual size dimorphism. In Fuente de Piedra colony, the lake dries out almost completely during the breeding season and both parents commute between breeding and foraging sites >130 km away during the chick-rearing period. Applying multistate capture-recapture models to daily observations of marked parents, we determined the effects of sex, and their interactions with other intrinsic and extrinsic factors, on the probability of chick desertion and sojourn in the colony and feeding areas. Moreover, using stable isotopes in the secretions that parents produce to feed their chicks, we evaluated sex-specific use of wetlands. The probability of chick attendance (complementary to chick desertion) was >0·98. Chick desertion was independent of parental sex, but decreased with parental age. Females stayed in the feeding areas for shorter periods [mean: 7·5 (95% CI: 6·0-9·4) days] than males [9·2 (7·3-11·8) days]. Isotopic signatures of secretions did not show sex differences in δ13C, but males' secretions were enriched in δ15N, suggesting they fed on prey of higher trophic levels than females. Both parents spent approximately 1 day in the colony, but females prolonged their mean stay when the lake dried out. Females also allocated more time to foraging in the flooded areas remaining in the colony, likely because they were energetically more stressed than males. The results indicate that sex-specific provisioning behaviour in greater flamingo is related to differential effects of both intrinsic and extrinsic factors. Males seem forage less efficiently than females, whereas females' body condition seems to be lower after feeding the chick. Our methodology may be extended to species that feed on distant food sources and that do not visit their offspring daily, to elucidate patterns of chick-provisioning behaviour. © 2013 British Ecological Society. Source

Rendon M.A.,CSIC - Donana Biological Station | Garrido A.,Edif Galia Center | Guerrero J.C.,Institute Ecologia y Ciencias Ambientales IECA | Rendon-Martos M.,Reserva Natural Laguna de Fuente de Piedra | Amat J.A.,CSIC - Donana Biological Station
Ibis | Year: 2012

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 14h. 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. © 2012 The Authors. Ibis © 2012 British Ornithologists' Union. Source

Amat J.A.,CSIC - Donana Biological Station | Rendon M.A.,CSIC - Donana Biological Station | Garrido-Fernandez J.,CSIC - Instituto de la Grasa | Garrido A.,Reserva Natural Laguna de Fuente de Piedra | And 2 more authors.
Behavioral Ecology and Sociobiology | Year: 2011

It was long thought that the colour of bird feathers does not change after plumage moult. However, there is increasing evidence that the colour of feathers may change due to abrasion, photochemical change and staining, either accidental or deliberate. The coloration of plumage due to deliberate staining, i. e. with cosmetic purposes, may help individuals to communicate their quality to conspecifics. The presence of carotenoids in preen oils has been previously only suggested, and here we confirm for the first time its presence in such oils. Moreover, the carotenoids in the uropygial secretions were the same specific pigments found in feathers. We show not only that the colour of feathers of greater flamingos Phoenicopterus roseus became more colourful due to the application of carotenoids from uropygial secretions over the plumage but also that the feathers became more colourful with the quantity of pigments applied over them, thus providing evidence of cosmetic coloration. Flamingos used uropygial secretions as cosmetic much more frequently during periods when they were displaying in groups than during the rest of the year, suggesting that the primary function of cosmetic coloration is mate choice. Individuals with more colourful plumage initiated nesting earlier. There was a correlation between plumage coloration before and after removal of uropygial secretions from feathers' surfaces, suggesting that the use of these pigmented secretions may function as a signal amplifier by increasing the perceptibility of plumage colour, and hence of individual quality. As the cosmetic coloration strengthens signal intensity by reinforcing base-plumage colour, its use may help to the understanding of selection for signal efficacy by making interindividual differences more apparent. © 2010 Springer-Verlag. Source

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