Tool use increases mechanical and bioenergetic foraging success in southern sea otters


Meeting Abstract

21-6  Saturday, Jan. 4 11:15 – 11:30  Tool use increases mechanical and bioenergetic foraging success in southern sea otters LAW, CJ*; TINKER, MT; FUJII, JA; NICHOLSON, T; STAEDLER, M; TOMOLEONI, J; YOUNG, C; MEHTA, RS; American Museum of Natural History; Nhydra Ecological Consulting; Monterey Bay Aquarium; Monterey Bay Aquarium; Monterey Bay Aquarium; US Geological Survey; California Department of Fish and Wildlife; University of California Santa Ccruz cjlaw9@gmail.com

Although it is well documented that tool use can facilitate the exploitation of resources, the fitness benefits associated with this innovative behavior are difficult to test. Using longitudinal data from 196 radio-tagged southern sea otters, we examined how variation in tool use frequency contributes to differences in foraging success (both biomechanically and energetically) and longer-term fitness between individuals. We found that individuals, particularly females, with high tool use frequency consumed harder prey items. Furthermore, we found a bi-modal relationship between tool use frequency and caloric income, revealing that not only does frequent tool use lead to greater caloric income but that non-tool using behavior serves as a viable strategy to maintain sufficient caloric requirements. Interestingly, these foraging advantages do not translate to long-term health gains as tool use frequency neither prevented tooth injury nor increased body condition. These results indicate that frequent tool users exhibit greater foraging success by gaining access to relatively harder prey, resulting in greater caloric intake.

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