Resumen El ruido antropogénico, que forma parte de un paisaje sonoro urbano, puede afectar negativamente el comportamiento de los animales En este estudio investigamos cómo la biofonía (sonidos de animales) se vió afectada por el ruido antropogénico en un fragmento de bosque urbano brasileño. Nuestra hipótesis es que el ruido y la biofonía difiren entre el borde y el centro del fragmento de bosque (es decir, una menor biofonía en áreas ruidosas). Se usaron dos dispositivos de monitoreo acústico pasivo para grabar paisajes sonoros una semana al mes, 24 horas al día, de mayo a julio de 2012. El índice de complejidad acústica (ACI) se usó para cuantificar la biofonía y la densidad espectral de potencia (PSD) para cuantificar el ruido urbano. Se obtucieron mayores valores de PSD y ACI en el borde que en el centro del fragmento. La PSD fue menor en julio, mientras que el ACI no varió significativamente entre meses. Los niveles de ruido también fueron más altos en el borde, mientras que la riqueza potencial de especies fue mayor en el centro del fragmento de bosque. Una mayor biofonía en áreas ruidosas puede ser interpretada como el efecto de respuestas conductuales de las especies con el fin de establecer una comunicación efectiva. Alternativamente, podrían ser el resultado de la segregación de especies por grado de plasticidad vocal o debido a diferencias en la composición de las comunidades.

Abstract Anthropogenic noise, which is part of an urban soundscape, can negatively affect the behaviour of wild animals. Here we investigated how biophony (animal sounds) was affected by noise in an urban Brazilian forest fragment. Our hypothesis was that noise and biophony would differ between the border and the centre of the forest fragment (i.e., lower biophony predicted in noisy areas). Two passive acoustic monitoring devices were used to record soundscapes one week per month, 24 hour per day, from May to July 2012. The Acoustic Complexity Index (ACI) was used to quantify biophony and the Power Spectral Density (PSD) to quantify urban noise. PSD and ACI were higher on the border than in the centre of the fragment. PSD was lower in July, while the ACI did not significantly vary between months. Noise levels were also higher on the border. Conversely, potential species richness was higher in the centre of the forest fragment. Higher biophony at noisy sites can be interpreted as behavioural responses of species for communicating in noisy areas. Alternatively, they could be the result of species segregation by degree of vocal plasticity or due to differences in composition of communities.

Abstract Distress can be defined as a biological response of an individual to long-term threats to its homeostasis and it should be avoided from an animal welfare perspective. High levels of stress hormones and the expression of abnormal behaviours are responses normally observed in distressed animals. Captive environments can provoke distress, especially when inappropriate stimuli are provided to the animals. The concomitant use of behavioural and non-invasive hormonal measures is a means to evaluate captive animal welfare. Environmental enrichment is a tool that can reduce distress and minimize the expression of abnormal behaviour in captive animals. The aim of this study was to evaluate greater rheas’ responses (behavioral and hormonal) to food-based enrichment. Three birds from the Belo Horizonte Zoo, Brazil were studied. The study was divided into three phases (baseline, enrichment and post-enrichment): fruits scattered around the birds’ enclosure were used as enrichment. Behaviour and faecal sampling were undertaken in all phases of the study. Abnormal behaviours and faecal glucocorticoid metabolites (GCM) levels showed significant reduction during the environmental enrichment phase, and a significative positive correlation between GCM production and abnormal pacing was observed. From the results of this study, we conclude that the use of food as environmental enrichment should be encouraged because of its positive effects on animal welfare. Besides, studies with larger groups of greater rheas, with individuals of both sexes, should also be encouraged to evaluate if the results found in this pilot study are consistent and can be generalized to the species.