Tool use increases mechanical foraging success and tooth health in southern sea otters ().

Although tool use may enhance resource utilization, its fitness benefits are difficult to measure. By examining longitudinal data from 196 radio-tagged southern sea otters (), we found that tool-using individuals, particularly females, gained access to larger and/or harder-shelled prey. These mechanical advantages translated to reduced tooth damage during food processing.

Effects of ontogeny and oiling on the thermal function of southern sea otter () fur.

During the evolution of most marine mammals, fur as an insulator has been replaced with more buoyant, energy storing and streamlining blubber. By contrast, the sea otter () relies on insulation from its dense, air-trapping pelage, which differs morphologically between natal and adult stages. In this study, we investigated the ontogenetic changes in thermal function of southern sea otter () pelts in air, in water, and when saturated with crude oil.

Robust age estimation of southern sea otters from multiple morphometrics.

Reliable age estimation is an essential tool to assess the status of wildlife populations and inform successful management. Aging methods, however, are often limited by too few data, skewed demographic representation, and by single or uncertain morphometric relationships. In this study, we synthesize age estimates in southern sea otters from 761 individuals across 34 years of study, using multiple noninvasive techniques and capturing all life stages from 0 to 17 years of age.

Non-trophic impacts from white sharks complicate population recovery for sea otters.

Complex interactions between protected populations may challenge the recovery of whole ecosystems. In California, white sharks () mistargeting southern sea otters () are an emergent impact to sea otter recovery, inhibiting the broader ecosystem restoration sea otters might provide. Here, we integrate and analyze tracking and stranding data to compare the phenology of interactions between white sharks and their targeted prey (elephant seals, ) with those of mistargeted prey (sea otters, humans).