Fecal hormones and blood sample data for evaluating sources of stress in Otaridids, wild northern fur seals, 2016-2017

This project makes use of biological samples and data obtained during diet manipulation experiments with captive northern fur seals #_msocom_1 . This study analyzes a complementary set of blood samples, fecal samples, and physiological data that was obtained from fur seals subject to changing diets – including controlled periods of nutritional stress – on a seasonal basis. Five trained female northern fur seals (born June 2008) underwent two sets of controlled feeding trials from 14 January to 26 May 2016, and between 01 November 2016 to 04 April 2017. Each fur seal was subject to 5 different diets for 3 weeks per diet. The experimental diets were designed to provide different levels of food mass and macronutrient intake while maintaining a relatively constant gross energy intake. There were 5 diets fed at normal ad libitum intake levels within training requirements, as well as a period of Restriction, where food intake was limited to induce body mass loss. Blood samples were collected at the start and end of each diet for hematology, biochemistry, and hormone analysis (T3, T4, and cortisol). Fecal samples were also collected after each diet for hormone analysis (T3, T4, corticosterone) and determining dry matter digestibility. Additional physiological variables collected included daily body mass, body composition (via deuterium dilution), and resting metabolic rate (via gas respirometry.