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Connectivity among habitat patches has mainly been studied in relation to species-specific behaviours. However, the movements of animals among patches may have different functions, and tolerance to gaps between habitat patches may vary between these functions. We tracked the movements of greater flamingos during the breeding and post-breeding periods with the aim of illustrating how the degree of connectivity may vary depending on the biological processes underlying the movements between wetlands. Most foraging sites used by breeding adults in a colony in southern Spain were within 200 km of the colony site, although some birds eventually moved 400 km. After the breeding season, the adults remained for several weeks in specific wetlands, moving to other sites located 280-2100 km away to overwinter. During these movements the birds may use stopover sites, the conservation of which may be critical to facilitate long-range movements. Our results suggest that wetland connectivity during chick rearing does not seem to be determined by whether or not central-place foraging flamingos are able to reach wetlands located at the longest distance that they are able to fly during non-stop flights (>1000 km), but by whether they are able to sustain the energetic costs derived from frequent commuting. In contrast, long-distance movements were occasionally undertaken during the post-breeding period. The energetic costs of such flights could be paid by flamingos because these movements were infrequent. Thus, in the case of flamingos, connectedness thresholds between wetlands vary depending on the biological process involved (chick rearing or post-breeding movements). This emphasizes the need to consider different types of connectivity in conservation planning..

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Greater flamingos in southern Spain foraged in areas distant from a breeding site, spending 4-6 days in foraging areas between successive visits to the colony to feed their chicks. During four years, we took blood samples from chicks to ascertain whether there were interannual variations in several blood parameters, indicative of food quality and feeding frequencies. When the chicks were captured, 20-31% of them had their crops empty, indicating that not all chicks were fed daily. Additional evidence of variations in feeding frequencies was obtained from a principal component analysis (PCA) on plasma chemistry values, which also indicated that there were annual variations in the quality of food received by chicks. The association of cholesterol and glucose with some PC axes indicated that some chicks were experiencing fasting periods. Of all plasma metabolites considered, cholesterol was the best one to predict body condition. Greater flamingo chicks experiencing longer fasting intervals, as suggested by higher plasma levels of cholesterol, were in lower body condition.