Ecologists have long observed that when food becomes scarce, animal populations exploit a wider range of food sources. But in the new research, University of California-Santa Cruz scientists studying southern sea otters at different sites in California's coastal waters found such diversity wasn't reflected in the diets of individual sea otters, which instead showed a diverse array of feeding strategies that included individual sea otters specializing in particular types of prey.

"The traditional way of viewing the relationships between predators and prey and how food webs are structured may be oversimplified," said University of California-Santa Cruz research biologist Tim Tinker, noting one implication is that some otters might be exposed to certain food-borne pathogens much more frequently than otters with different diets.

"A lot of sea otters in the central coast population are dying from infectious diseases and this could help us to better understand that disease mortality by allowing us to pinpoint the specific vectors of disease transmission," Tinker said.

The study appears in the online issue of the Proceedings of the National Academy of Sciences.