Stress in captive Blue-fronted parrots ( Amazona aestiva): the animalists’ tale

Abstract

Lay summary

Captivity has traditionally been considered a stressful habitat for wildlife. In this study, urofaecal glucocorticoid metabolites of wild and captive Blue-fronted amazon parrots ( Amazona aestiva) subjected to different husbandry systems were determined. Results reveal lower corticoid levels in individuals maintained in captivity than in the free-ranging ones.

Abstract

Understanding stress physiology is crucial for species management because high levels of stress can reduce reproduction and the individual’s ability to face threats to survive. One of the most popular methods for non-invasive monitoring of animal endocrine status is the glucocorticoid (GC) metabolite measurements, which can provide important information about how animals are affected by their surrounding environment. Here, we carried out the biological validation of corticosterone enzyme immunoassays (EIAs), which together with a cortisol EIA was used to quantified the concentrations of urofaecal GC metabolites (uGCMs) in wild and captive Blue-fronted amazon parrots ( Amazona aestiva). Urofaecal GC concentrations were significantly higher ( P < 0.05) in free-living parrots (157.9 ± 18.5 ng cortisol/g and 61.14 ± 23.5 ng corticosterone/g dry urofaecal sample) than in those kept in captivity, which showed the comparable levels of GC metabolites independently of the management system applied. The higher uGCM levels obtained in the wild population point to an adaptive response for survival and species propagation in a more challenging environment, in comparison with captive animals. Furthermore, the lower uGCM concentrations in captive parrots may indicate an adaptive capacity of the species A. aestiva to captivity and its potential as a legal pet. The corticosterone EIA applied in this study proved to be an effective technique for the adrenocortical activity monitoring in this species. We discuss our findings considering the management and destiny given to wild-caught birds that are kept in confinement or returned to nature.