Daniel E. Crocker
University of California (Santa Cruz).
Comparative Physiology of Vertebrates; Physiological Ecology; Bioenergetics; Behavioral Ecology; Biology of Marine Mammals.
My research is focused on the physiological and behavioral ecology of pinnipeds, seals and sea lions. My approach is to integrate physiology and behavior with the aim of addressing ecological theory. I am investigating physiological factors that impact the reproductive and foraging strategies used by marine predators. Much of my current research is focused on the physiology and behavior of northern elephant seals. These investigations include both field and laboratory studies. I am currently investigating the metabolic physiology and biochemistry of extended fasting in seals in research funded by NSF. I am investigating oxidative stress mechanisms in seals in NIH funded research in collaboration with Rudy Ortiz from UC Merced. I am investigating endocrine stress responses in marine mammals in work funded by the Office of Naval Research. My graduate students are exploring a wide variety of research areas including fasting physiology, diving physiology, development, stress responses, foraging behavior and life history strategies.
Recent Selected Publications:
Crocker. D.E., C.D. Champagne, M.A. Fowler, and D.S. Houser. 2014. Adiposity and fat metabolism in lactating and fasting northern elephant seals. Advances in Nutrition. 1: 57-64.
Fowler, M.A., C. Debier, E. Mignolet, C. Lignard, D.E. Crocker, D P. Costa. 2014. Fatty acid mobilization and comparison to milk fatty acid content in northern elephant seals. Journal of Comparative Physiology B. 184: 125-135.
Crocker, D.E. M.A. Fowler, C.D. Champagne, A.L. Vanderlugt and D.S. Houser. 2014. Metabolic response to a glucagon challenge varies with adiposity and life-history stage in fasting northern elephant seals. General and Comparative Endocrinology 195:99-106.
Tift, M.S. E.L. Ranalli, D.S. Houser, R.M. Ortiz, and D.E. Crocker. 2013. Development enhances hypometabolism in northern elephant seal pups (Mirounga angustirostris). Functional Ecology. 27:1155-1165.
Hassrick, J.L., D.E. Crocker, and D.P. Costa. 2013. Effects of maternal age and mass on foraging behavior and foraging success in the northern elephant seal. Functional Ecology. 27:1055-1063.
Houser, D.S. C.D. Champagne and D.E. Crocker. 2013. A non-traditional model of the metabolic syndrome: the adaptive significance of insulin resistance in fasting-adapted seals. Frontiers in Endocrinology 4:1-10.
M. Suzuki, J.P. Vázquez-Medina, J.A Viscarra, J.G. Soñanez- Organis, D.E. Crocker, and R.M. Ortiz. 2013. Activation of systemic, but not local, renin-angiotensin system is associated with up-regulation of TNF-α during prolonged fasting in northern elephant seal pups. Journal of Experimental Biology. 216:3125-3221.
J.G. Soñanez-Organis, J.P. Vázquez-Medina, D.E. Crocker and R.M. Ortiz. 2013. Prolonged fasting activates hypoxia inducible factor -1α, -2α and -3α in a tissue-specific manner in northern elephant seal pups. Gene. 526:155-163.
Vàzquez-Medina, J.P., J.G. Soñanez-Organis, R.Rodriguez, J.A. Viscarra, A. Nishiyama, D.E. Crocker, and R.M. Ortiz. 2013. Prolonged fasting activates Nrf2 in postweaned elephant seals. Journal of Experimental Biology. 216:2870-2878.
Tavoni, S.K., C.D. Champagne, D.S. Houser and D.E. Crocker. 2013. Lactate flux and gluconeogenesis in fasting, weaned northern elephant seals (Mirounga angustirostris). Journal of Comparative Physiology B. 4:537-546.
Champagne, C.D., S.M Boaz, M.A Fowler, D.S. Houser, D.P. Costa. and D.E Crocker. 2013. A profile of carbohydrate metabolites in the fasting northern elephant seal. Journal of Comparative Physiology D. 8:141-151.
Currylow, A.F., M.S. Tift, J.L. Meyer, D.E. Crocker, and R.N. Williams. 2013. Seasonal variations in plasma vitellogenin and sex steroids in male and female eastern box turtles, Terrapene c. carolina. General and Comparative Endocrinology. 180: 48-55.
Crocker, D.E., D.S. Houser, and P.M. Webb. 2012. Impact of body reserves on energy expenditure, water flux, and mating success in breeding male northern elephant seals. Physiological and Biochemical Zoology. 85:11-20.
Crocker, D.E., R.M. Ortiz, D.S. Houser, P.M. Webb and D.P. Costa. 2012. Hormone and metabolite changes associated with extended breeding fasts in male northern elephant seals (Mirounga angustirostris). Journal of Comparative Biochemistry and Physiology A. 161:388-394.
Animal Physiology, Environmental Physiology; Bioenergetics; Biometry; Animal Behavior.