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.
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.
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.
Houser, D.S., D.E. Crocker, M.S. Tift and C.D. Champagne. 2012. Glucose oxidation and non-oxidative glucose disposal during prolonged fasts of the northern elephant seal pup (Mirounga angustirostris). American Journal of Physiology: Regulatory, Integrative and Comparative Physiology. 303: 562-570.
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.
Champagne, C.D., D.S. Houser, M.A. Fowler, D.P. Costa, and D.E. Crocker. 2012. Gluconeogenesis is associated with high rates of tricarboxylic acid and pyruvate cycling in fasting northern elephant seals. American Journal of Physiology: Regulatory, Integrative and Comparative Physiology. 303:340-352.
Champagne, C.D., D.E. Crocker, M.A. Fowler and D.S. Houser. 2012. Fasting physiology of the pinnipeds: the challenges of fasting while maintaining high energy expenditure and nutrient delivery for lactation. In: The Comparative Physiology of Starvation, Fasting and Food Limitation. (ed. M.D. McCue). Springer-Verlag, Berlin. pp. 309-336.
McDonald, B.I., M.E. Goebel, D.E. Crocker, and D.P. Costa. 2012. Dynamic influence of maternal and pup traits on maternal care during lactation in an income breeder, the Antarctic fur seal. Physiological and Biochemical Zoology. 85: 243-254.
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.