The Cayumapu River black-necked swan (Cygnus melanocoryphus) population in southern Chile suffered a syndrome of
malnutrition and hyperferremia in 2005. The
iron metabolic imbalance could not be explained on the basis of the quality of their diet. Hence, the primary objective of this study was to determine the relationship between
malnutrition and
iron homeostasis in black-necked swans. It was proposed that catabolic processes could increase serum
iron levels due to the release of endogenous
iron from tissues. A free-living swan population undergoing natural nutritional imbalance due to molting was studied. In addition, swans captured were subjected to a diet restriction until they became emaciated. The results revealed that neither lipolytic activity nor
emaciation affected serum
iron concentrations. The increment of total
iron binding capacity observed was in agreement with the reduction of endogenous
iron stored, with the increase of erythropoeitic demand, or with both. Future studies are needed to determine the effect of incremental erythropoietic activity on
iron homeostasis in anemic, malnourished birds.