Boldness at the nest predicts foraging and diving behaviour of female but not male African penguins

Optimal foraging theory suggests that the environment (e.g. distribution of resource patches) will shape an individual's decision to exploit the resource available or explore other locations. Together with the environment and the social context, individual characteristics such as personality have been recently discovered to affect behaviour, offering new insights in the field of behavioural ecology. In many species, personality types differ in breeding success, and foraging behaviour could potentially mediate the influence of personality on reproductive output. A recent study conducted on African penguins, Spheniscus demersus, revealed that bold and shy individuals raised chicks with different growth rates. Here we investigated whether strategies of resource acquisition vary with personality, that is, boldness degree, which may explain the differences in breeding success previously observed in this endangered species. Over 3 years, we deployed GPS loggers, sometimes in conjunction with time-depth recorders, on chickrearing penguins on Bird Island, Algoa Bay, South Africa, and recorded their boldness degree using a standard human approach protocol. Bolder females, but not males, foraged following a more sinuous path than shyer ones. Similarly, wiggle frequency and the total vertical distance travelled underwater increased with female boldness degree. These results suggest different resource acquisition strategies between personality types in female African penguins. However, none of the foraging or diving behaviour characteristics influenced breeding success. These findings suggest that personality may influence breeding success through other mechanisms (e.g. chick provisioning). Our study indicates that, in this species, some nest behaviours (i.e. proxy of personality) may link with foraging and diving behaviours more than others. Nevertheless, the sex-specific adaptation observed in foraging and diving behaviour may result from a differential investment in the breeding season and reduce intraspecific competition for food in this species. (C) 2019 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.