On behalf of myself and my coauthors I am excited to share our recent paper on a unique foraging behavior in sea otters in Washington state, published in *Northwestern Naturalist *last week titled "Rapid consumption of kelp crab: implications for sea otters in Washington state." The paper can be found here: http://doi.org/10.1898/NWN20-07
Abstract: As animal populations approach environmental carrying capacity, competition for food increases, generally leading to decreased individual energy intake rate. Energy-intake rate can therefore be used as one metric of population status relative to carrying capacity. Focal observations of Sea Otter (*Enhydra lutris*) foraging behavior have been used throughout their range to estimate energy-intake rates and infer population status. In Washington State, previous research has demonstrated that handling times for Kelp Crabs (*Pugettia spp.*) by Sea Otters are 1.5 to 2 times faster than those observed in California and British Columbia, resulting in higher energy-intake rate estimates for Sea Otters in Washington. We investigated potential causes for the difference in handling time by: (1) comparing Sea Otter handling times of Kelp Crab and non-Kelp Crab prey items in Washington, California, and British Columbia; (2) comparing the handling times of Kelp Crabs by a subset of Sea Otters in California, which are Kelp Crab specialists (2003–2012, *n* = 244 Kelp Crab captures) to those of Sea Otters in Washington (2015–2018, *n* = 541 captures) and British Columbia (2013–2017, *n* = 359 captures); and (3) comparing the biomass-to-width ratios of Kelp Crabs from Washington and California. We did not observe consistent differences between regions in Sea Otter handling times of non-Kelp Crab prey. Mean Sea Otter handling time of small Kelp Crabs (carapace ≤1 Sea Otter paw width) in Washington (32.7 s) was significantly faster than in British Columbia (52.0 s, *P* < 0.0001) and all of California (40.6 s, *P* < 0.0001), but was not significantly different from that of Kelp Crab-specialist Sea Otters in California (31.7 s, *P* = 0.313). Mean Sea Otter handling time of large Kelp Crabs (≥1 Sea Otter paw) in Washington (64.7 s) was significantly faster than in British Columbia (87.7 s, *P*= 0.003), in all of California (104 s, *P* < 0.0001), and in the subset of Kelp Crab-specialist Sea Otters in California (91.6 s, *P* = 0.007). Kelp Crabs in Washington had a larger biomass-to-width ratio than Kelp Crabs in California: in Washington, a Kelp Crab with a 20-mm maximum carapace width had a 3.8% greater predicted biomass than a Kelp Crab in California of the same width, and a 27.1% greater biomass for a 60-mm carapace. Our results suggest that Sea Otters in Washington are Kelp Crab specialists with behavioral differences allowing them to consume Kelp Crabs faster, a difference that may affect the inference of Sea Otter population status from energy-intake rates in Washington. -- *Carter Johnson (he/him/his)* PhD Student University of Alaska Fairbanks College of Fisheries and Ocean Sciences 17101 Point Lena Loop Rd | Juneau, AK cjjohnso...@alaska.edu
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