Birds

Cavity limitations and interspecific competition render large macaws valuable models for elucidating the integration of parental care, pair-bond maintenance, and nest defense across reproductive stages. Through continuous video monitoring of a single artificial polyvinyl chloride nest box in the Tambopata National Reserve, Peru, we quantified the complete breeding cycle of a resident green-winged macaw (Ara chloropterus) pair and the visitation behavior of a sympatric scarlet macaw (Ara macao) pair within the same cavity. We constructed daily time budgets for 17 behaviors, categorized into seven functional groups, from motion-triggered video clips; employed multivariate tests; and generalized additive models with beta error distribution to describe the temporal changes across the five reproductive stages. The resident A. chloropterus exhibited a significant reorganization of parental investment, with early courtship behaviors transitioning to peak nest attendance and sentinel vigilance during incubation and early brooding. In later stages, locomotion increased significantly, associated with chick provisioning, whereas the frequency of allopreening remained relatively constant throughout the cycle. The visiting A. macao displayed a brief, behaviorally rich prospecting phase, characterized by nest inspection and locomotion, followed by a sharp decline in minimal activity. These divergent strategies align with owner–intruder asymmetries and floater dynamics, indicating that artificial cavities can support A. chloropterus breeding, while suggesting that additional cavities may redistribute breeding opportunities among competing macaws, a hypothesis necessitating multi-nest and multi-year evaluation.

The possibility of sex identification in birds is of substantial importance for studies on various aspects of their ecology and behaviour. Discriminant functions have become increasingly popular in studies of bird species that are monomorphic in plumage characteristics because these methods are inexpensive and non-invasive. In this paper, we provide the first discriminant function that could potentially aid in determining sex in a common wader species, the Wood Sandpiper, based on external body measurements. Females were larger than males in all linear body measurements; however, no single measurement can be used to determine sex due to the high degree of overlap between the sexes. Discriminant equation with the most commonly used linear measurements, wing length and bill length, was provided. Identifying birds with discriminant function values D₃ < –0.409 as males and those with D₃ > 0.217 as females would lead to sex misclassification of only 5% of individuals of each sex, but it would leave as many as 83% of the individuals unsexed. Allowing for a misclassification of 10% would shift the cut-off values to −0.509 for males and 0.633 for females and reduce the number of unsexed birds to 66%. The method presented here allows us to account for sex-specific patterns in future ecological studies of the Wood Sandpiper and can be applied to past data.

Illegal wildlife trade exerts severe pressure on wild parrot populations, and confiscated parrots often end up in rescue centers where they are rehabilitated for release. However, parrots kept in captivity often develop potentially maladaptive behaviors, including attraction to humans. This behavior can increase the risk of recapture. We modified and tested a previously published human aversion training (HAT) protocol designed to reduce human attraction in confiscated Amazona parrots. The HAT consisted of observers either on the ground or on a ladder, offering food to a single individual and then feigning capture of birds that approached or failed to move away from the observer. Twelve Yellow-naped Amazons (Amazona auropalliata) underwent 36 sessions of HAT over a 14-week period. Ten additional birds were held without training as a control. All birds were evaluated through food offer tests (FOTs) before, during, and after the experiment (FOT scores ranged from 1 when the bird approached the observer to 6 when the bird flew away). Over the training period, both groups showed increased aversion to people. However, contrary to our predictions, aversion scores were not higher for the group given aversion training. Aversion training also did not have a strong impact on fate post-release: within a month of release, 40% of the 22 birds were recaptured in a nearby village, including 4 treatment and 5 control birds. Overall, these results suggest that holding these birds in monospecific groups increased aversion to humans. However, the intense training aversion protocol did not further increase the fear of humans in these Amazona parrots, many of which may have been pets for years before entering the program. This study suggests that rehabilitation and release projects should regularly evaluate the impacts of their training programs and improve or eliminate costly protocols that do not achieve stated objectives.