Inferring prey size variation from mandible acceleration in northern elephant seals
Abstract
Prey size is an important factor for predators as it affects prey quality (energy content) and hence total energy gain. However, it remains challenging to obtain information about prey size from free‐ranging marine predators. Here, we developed a method that estimates prey size using mandible acceleration in captive northern elephant seals and then applied it to 34 free‐ranging seals. In captive seals, the number of feeding‐related acceleration signals were positively related to prey size category (1,000 m), suggesting that seals foraged mainly on smaller prey (possibly 15 cm) at deeper depths. These results suggest that seals might compensate for higher energetic costs of deeper‐diving by targeting larger prey. Although our study has practical limitations (e.g., calibrating prey size in captive conditions), our method allows concurrent inference of prey size and foraging behavior, being potentially useful to investigate how predators adjust their behavior in response to the changes in the foraging environment.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Dec 12, 2018
- Source ID
- 10.1111/mms.12571
Entities
People
- Akinori Takahashi
- Daniel P. Costa
- Luis A. Hückstädt
- Michael S Tift
- Taiki Adachi
- Yasuhiko Naito
Organizations
- Japan Society for the Promotion of Science
- National Institute of Polar Research
- Office of Naval Research
- University of California, Santa Cruz