Seasonal Differences in Immune Profiles and Body Conditions of Migratory and Permanent Resident Neotropical Flycatchers

[摘要] Abstract. The activation and maintenance of the immune system demand a cost of nutrition and energy, and this demand may result in a trade-off with other energetically demanding activities. To test for such a trade-off, in the cerrado of central Brazil, we compared the immune profile and body condition of the resident Plain-crested Elaenia (Elaenia cristata) in the rainy nonbreeding season with that in the dry breeding season. Then we compared the immune profiles and body conditions of the Plain-crested Elaenia and Lesser Elaenia (Elaenia chiriquensis), a migrant, during the breeding season. Finally, we compared the immune profiles of the Plain-crested Elaenia at four stages of molt. The Plain-crested Elaenia's immunosuppression profile was typical (decreased lymphocyte number, increased heterophil number, and H:L ratio) during the dry season but not at other seasons. Condition measured as a body-mass index did not vary significantly by season. The Plain-crested Elaenia's immunosuppression profile did not...

[学科分类] 动物科学

[关键词] body condition;Elaenia cristata;Elaenia chiriquensis;immune system;leukocyte