Do bolder parents make better parents in anthropogenically disturbed environments?

Abstract Urban developments and human activities are encroaching on our natural habitats at a rapidly increasing rate, placing many species under stress from anthropogenic disturbance. Animal personality can influence how individuals tolerate disturbance in their environment. We examined the relationships between boldness and breeding success in a highly anthropogenically disturbed population of little penguins ( Eudyptula novaehollandiae ) on Granite Island, South Australia. We measured boldness in individual penguins both at the nest (in response to a simulated nest intrusion; nest defence scores) and away from the nest (in response to a human approach; alert and flight initiation distances). We first assessed the repeatability of boldness across time and contexts, and then determined the relationships among boldness, parental care behaviours (return rate to the nest, feed rate to chicks, and number of overnight stays) and breeding success (number of chicks fledged). Nest defence scores were highly repeatable across months and years. Responses to a human approach (alert and flight initiation distances) were not repeatable, with penguins increasing their flight initiation distance across repeated trials. Mean nest defence scores positively correlated with the first flight initiation distance recorded, supporting the idea that both responses may be mediated by the same underlying personality trait (boldness). Neither nest defence score nor response to human approach predicted parental care or breeding success. Our results suggest that constant exposure to anthropogenic disturbance may have negative effects on little penguins and highlight the importance of limiting interactions between human visitors and penguins.