Dear Colleagues, We are pleased to announce the recent publication of the following article in The Journal of Experimental Biology, regarding the reproductive energetics of sea otters: Thometz, N.M., Kendall, T., Richter, B., Williams, T.M. (2016) “The High Cost of Reproduction in Sea Otters Necessitates Unique Physiological Adaptations.” The Journal of Experimental Biology 219(15): 2260-2264. *Abstract*: Superimposed on inherently high basal metabolic demands, the additional energetic requirements of reproduction can push female sea otters beyond physiological limits. Indeed, the resulting energy imbalance contributes to disproportionately high rates of mortality at the end of lactation in this species. To examine and quantify metabolic changes associated with reproduction, we measured the resting metabolic rate (RMR) of a female sea otter across gestation, lactation, and non-reproductive periods. Concurrently, measurements were made on a non-breeding control female. Our results suggest that RMR declines during gestation. Conversely, RMR increases during lactation, reaches a peak at 3-4 months postpartum, and remains elevated until weaning. Combining these direct measurements with published data, we found the cost of pup rearing to be significantly higher than previously estimated. High baseline energy demands and limited energy reserves, combined with significant lactation and pup rearing costs, appear to necessitate metabolic and thermal lability during key reproductive stages. Please direct all inquiries to nthometz@ucsc.edu Best, Nicole M. Thometz, PhD Postdoctoral Researcher Ecology & Evolutionary Biology Department University of California Santa Cruz Long Marine Lab - Center for Ocean Health 100 Shaffer Road, Santa Cruz CA 95060