Stella Villegas-Amtmann

Ph.D. Ecology and Evolutionary Biology, UC Santa Cruz

B.S. Universidad Nacional Autonoma de Mexico

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ResearchGate Profile



Research Interests

My research focuses on the ecological physiology of marine mammals. Particularly, I study the diving behavior and physiology of Galapagos and California sea lions, looking at individual variability and foraging specialization and how it can be applied for their management and conservation. I am interested in how latitudinal range and seasonal/environmental change influence the foraging behavior and physiology of different otariid species. I look at how environment and behavior influence the diving physiology and metabolic rate of Galapagos sea lions. I am also working on developing bioenergetic models of baleen whales, specifically gray, humpback and blue whales, to predict population consequences of disturbance in order to be implemented in management plans.

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  • Villegas-Amtmann S; Schwarz L.K and Costa D.P (in prep.) East or west, how much does it cost to be a gray whale? Evaluating population consequences of disturbance.
  • Villegas-Amtmann S; McDonald B; Paez-Rosas D; Aurioles-Gamboa D and Costa D.P (in prep.) Adapted to change: Low energy requirements in a low and unpredictable productivity environment, the case of the Galapagos sea lion.
  • Villegas-Amtmann S and Costa D.P (submitted) The Galapagos sea lion (Zalophus wollebaeki) foraging ecology, diving physiology and reproductive behavior. In: Tropical Pinnipeds Bio-ecology, Threats and Conservation. Science Publishers. CRC Press/Taylor & Francis Group.
  • Villegas-Amtmann S; Schwarz L.K; Sumich J.L and Costa D.P. (2015). A bioenergetics model to evaluate demographic consequences of disturbance in marine mammals applied to gray whales. Ecosphere 6(10):183.
  • Schwarz L.K; Villegas-Amtmann S; Beltran R.S; Costa D.P; Goetsch C; Huckstadt L; Maresh J.L and Peterson S.H. (2015). Comparisons and uncertainty in fat and adipose tissue estimation techniques: the northern elephant seal as a case study. PLoS ONE 10(6):e0131877. doi: 10.1371/journal.pone.0131877
  • Villegas-Amtmann S; Jeglinski J.E; Costa D.P; Robinson P and Trillmich F. (2013). Individual foraging strategies reveal niche overlap between endangered Galapagos pinnipeds. PLoS ONE 8(8): e70748. doi:10.1371/journal.pone.0070748
  • Villegas-Amtmann S; Atkinson S; Paras-Garcia A and Costa D.P (2012). Seasonal variation in blood and muscle oxygen stores attributed to diving behavior, environmental temperature and pregnancy in a marine predator. Comparative Biochemistry and Physiology Part A. 162:413-240.
  • Robinson P.W., Costa D.P., Crocker D., Gallo-Reynoso J.P., Champagne C., Fowler M., Goetsch C., Goetz K., Hassrick J., Huckstadt L.A., Kuhn C., Maresh J., Maxwell S.M., McDonald B., Peterson S., Simmons S.E., Teutschel N.M., Villegas-Amtmann S., Yoda K. (2012). Foraging Behavior and Success of a Mesopelagic Predator in the Northeast Pacific Ocean: Insights from a Data-Rich Species, the Northern Elephant Seal.PLoS ONE 7(5):e36728.doi:10.1371/journal.pone.0036728
  • Villegas-Amtmann S, Simmons SE, Kuhn CE, Huckstadt LA, Costa DP (2011). Latitudinal Range Influences the Seasonal Variation in the Foraging Behavior of Marine Top Predators. PLoS ONE 6(8): e23166. doi:10.1371/journal.pone.0023166.
  • Alava J.J; Ross P.S; Ikonomou M.G; Cruz M; Jimenez-Uzcátegui G; Dubetz C; Salazar S; Costa D.P; Villegas-Amtmann S; Howorth P & Gobas F.A.P.C. (2011). DDT in endangered Galapagos sea lions (Zalophus wollebaeki). Marine Pollution Bulletin, 62 (4):660-671.
  • Alava J.J, Salazar S; Cruz M; Jimenez-Uzcátegui G; Villegas-Amtmann S; Paez-Rosas D; Costa D.P; Ross P.S; Ikonomou M.G; & Gobas F.A.P.C (2011). DDT strikes back: Galapagos sea lions face increasing health risks. AMBIO, 40 (4): 425-430.
  • Costa D.P; Robinson P.W; Arnould J.P.Y; Harrison A-L; Simmons S.E; Hassrick J.L; Hoskins A.J; Kirkman S.P; Oosthuizen H; Villegas-Amtmann S &  Crocker D.E (2010). Accuracy of ARGOS Locations of Pinnipeds at-Sea Estimated Using Fastloc GPS. PLoS One 5(1): e8677. doi:10.1371/journal.pone.0008677
  • Villegas-Amtmann S and Costa D.P (2010). Oxygen stores plasticity linked to foraging behavior and pregnancy in a diving predator, the Galapagos sea lion. Functional Ecology, 24: 785-795.
  • Villegas-Amtmann S; Atkinson S and Costa D.P (2009). Low synchrony in the breeding cycle of Galapagos sea lions revealed by seasonal progesterone concentrations. Journal of Mammalogy, 90(5):1232–1237.
  • Robinson P.W., Villegas-Amtmann S, and Costa D.P (2009). Field Validation of an Inexpensive Time-Depth Recorder. Marine Mammal Science, 25(1): 199-205
  • Villegas-Amtmann S; Costa D.P; Tremblay Y; Salazar S and Aurioles-Gamboa D. (2008). Multiple foraging strategies in a marine apex predator, the Galapagos sea lion. Marine Ecology Progress Series, 363: 299-309.






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