Physiological parameters of a plover during nonbreeding and breeding seasons in Patagonia, Argentina

Abstract

Migratory shorebirds are of the most threatened avian species due to effects of human activities and climate change. Physiological parameters are useful to evaluate the health status of free-living animals. Here we investigated lymphocytes, heterophils, heterophils/lymphocytes, and glucose for female and male Two-banded plovers (TBPLs), Charadrius falklandicus (Latham, 1790) during nonbreeding (body moult) and breeding (incubation), in coastal areas of northern Patagonia Argentina. We also measured corticosterone for first time for the species during breeding. Nonbreeding TBPLs were more likely to have higher physiological measurements that were not dependent on body moult nor body condition, being similar between sexes. Differences found in glucose are likely related to recent feeding in nonbreeding birds compared with fasting during incubation. The gregarious nonbreeding behaviour in comparison with the isolated breeding pairs, would increase the risk of acquiring parasites and /or pathogens inducing a response of the immune system reflected in higher values of lymphocytes. Baseline corticosterone during breeding was similar between sexes and were lower compared with other values reported for breeding plovers. TBPLs undergo energetically demanding physiological changes during the nonbreeding stage, strengthening the idea that conservation of the environmental resources at these locations may be more important than previously thought.