Birds in highly leaded environments show stronger response to human gaze and higher vigilance

Description

To survive in urban environments, wildlife must correctly assess and respond to human disturbance and predation threats, for example, through gaze aversion (a fearful response to human gaze), vigilance, and fast escape responses. As initiation of these responses is mediated by the nervous system, neurotoxins such as lead likely influence these behaviours. In this study, we measured gaze aversion in house sparrows (Passer domesticus) in Broken Hill, Australia, a city exposed to prolonged and varied lead contamination. Using feeders fitted with remote sensors, we recorded the latencies for birds to approach a food source under direct and averted human gaze, in high- and low-leaded locations. We also quantified individual vigilance through scanning behaviour. High-leaded sparrows took longer to approach the feeder when under a direct gaze than an averted gaze, but this response is not present in low-leaded birds. Vigilance data also showed that high-leaded birds spent more time scanning the surroundings than low-leaded birds. Our results could be explained by poorer flight in highly-leaded birds, necessitating higher alertness to compensate, or an effect of lead exposure to fear responses. Our study highlights the importance to consider multiple environmental effects when investigating behavioural adaptations in animals.

Period	27-Jun-2023
Event title	Australasian Society for the Study of Animal Behaviour 2023 Conference
Event type	Conference
Conference number	ASSAB 2023
Location	Sydney, AustraliaShow on map
Degree of Recognition	International