Tool use increases mechanical foraging success and tooth health in southern sea otters (Enhydra lutris nereis)

Although it is well documented that tool use can enable the utilization of novel resources, the fitness benefits associated with this innovative behavior are difficult to test. Using longitudinal data from 196 radio-tagged southern sea otters, we found that individuals, particularly females, with frequent tool use gained access to harder, larger prey items. In turn, the mechanical advantages of tool use during food processing translated to reduced tooth damage in tool users. We also found that tool use diminishes trade-offs between access to different prey types, tooth health, and caloric intake that are highly dependent on the relative availability of prey in the environment. Overall, tool use allows individuals to maintain caloric requirements through the processing of alternative prey that are otherwise inaccessible without the use of tools, indicating that this innovative behavior is a necessity for the survival of southern sea otters in environments with depleted preferred prey., , , # Tool use increases mechanical foraging success and tooth health in southern sea otters (Enhydra lutris nereis)

[https://doi.org/10.5061/dryad.zgmsbcchs](https://doi.org/10.5061/dryad.zgmsbcchs)

## Description of the data and file structure

**dat.Rdata** contains a dataframe \"dat\" with the follow variables:

* otter = individual otter ID
* PDE = percent dentine exposure
* study = study area
* area = study area
* hardness = mean prey hardness index of otter (Newton)
* sex = sex of individual: F - female; M - male
* ageclass = age class of individual: A - adult, J - subadult, AA - aged adult
* prey = prey specialization of otter
* tool_use = tool use frequency (%)
* age = estimated age of otter (years)
* mass = body mass of otter (kg)
* length = body length of otter (cm)
* urchin_num = total number of urchins consumed by otter
* crab_num = total number of crabs consumed by otter
* mussel_num = total number of mussels consumed by otter
* clam_num = tota...