Are haematological parameters related to body condition,ornamentation and breeding success in wild burrowing parrots Cyanoliseus patagonus?

Haematology and plasma biochemistry values are useful tools for ecological research. They have been used to investigate the physiological state and the adaptation of individuals to their habitat, changes in nutritional state of birds, body condition, the level of parasite infestation, male quality, the physical condition of nestlings, etc. In the present study we tested the role of haematological and plasma biochemistry values in burrowing parrots Cyanoliseus patagonus (Aves, Psittaciformes) for determining individual quality and condition. We measured triglyceride levels, plasma protein levels, plasma hue and erythrocyte sedimentation rate of nestlings and breeding adults in a colony in the north of Patagonia, Argentina. We found that plasma triglyceride levels strongly relate to changes in individual condition. Plasma levels of triglycerides were found to be strongly related to mass change, hatching order and brood size in nestlings. Levels of triglycerides were found to reflect reproductive effort in adults: males fledging larger broods had decreased levels of triglycerides. Adults with lower body condition had increased erythrocyte sedimentation rates. Plasma hue showed a strong relationship with an ornamental trait, the red abdominal patch of male adults, and with parameters of structural body size. Thus, we have shown that haematological and plasma biochemistry values, especially plasma levels of triglycerides, are good indicators of individual quality and condition in nestlings and breeding birds.