Inter-Research > MEPS > v682 > feature  
Marine Ecology Progress Series

via Mailchimp
Imperial shag are extraordinary birds that catch prey at depths of tens of metres underwater. Bird-attached video cameras detail how they do this.

Photo: Andrea Benvenuti

Wilson RP, Holton MD, Neate A, Del’Caño M, Quintana F, Yoda K, Gómez-Laich A

Luck and tactics in foraging success: the case of the imperial shag

How often animals find food affects their survival and reproduction and dictates population trajectories. However, very few studies document this in wild animals. We deployed cameras on free-living imperial shag to define how long the birds spent searching between prey items and to estimate prey energy values. Prey encounter rates were not different from random (luck-based) in 10% of the individuals while all others did no better than random if accrued energy was modelled to predict brood provisioning rates. There were, however, substantial inter-individual differences in prey encounter rates. We suggest that these birds work within an essentially luck-based environment, but successful individuals have strategies, including where, when and how to forage, that give them better odds of finding prey.


Abstract   Back to contents page   Link to full PDF