Research in the Laboratory of Integrative and Comparative Herpetology (LICH) seeks to understand how forces such as evolutionary history, the physical environment, and interactions among species affect an animal's morphology, physiology, ecology, behavior, and life history. In short, we study the "how" and the "why" of animal function. We study these relationships principally in amphibians and reptiles because they are ideal organisms for testing hypotheses that lie at the interface of physiology, behavior, ecology, and evolution. Recent studies have included a blend of field observations, measurements, and experiments, laboratory benchwork and experiments, and computer simulations. Usually our research draws from several levels of biological inquiry: subcellular, tissues, individuals, populations, and communities. However, we tend to emphasize the biology of whole organisms and to draw broader inferences from modern comparative analyses. I also conduct research with colleagues in Argentina on a large clade (>250 species) of austral South American lizards (Liolaemidae). This lineage offers an excellent model system for answering a variety of questions that are of general interest to comparative biologists.

Current Research

A number of research projects are currently underway. Several of these are externally funded and all involve student participants.

• Thermal biology of small lizards from cold climates
• Temperature-dependent performance of atypical geckos (diurnal and cold-climate species)
• Evolution and biological consequences of diet, especially herbivory in reptiles
• Evolution and ecophysiological implications of reproductive modes in squamate reptiles
• Speciation, species boundaries, and phylogeny of Liolaemus and Phymaturus lizards

I enjoy working with undergraduate and graduate students who share my interests in herpetology, or aspects of the evolution, functional morphology, physiology, and ecology of most vertebrates. Our laboratory facilities--coupled with those in the department, university, and the southern California environment--provide excellent opportunities for research. I offer a supportive yet critical environment for fulfilling intellectual and academic pursuits. You can learn more about research opportunities and expectations for investigators in LICH here. [pdf]

Current Student Projects

• Alissa N. Luken (MS student): Testing Dollo's law on physiology: do secondarily diurnal geckos return to temperature-dependent performance levels of typical diurnal lizards
• Jose W. Monzon (MS student): The digestive benefits and underlying mechanims of postprandial thermophily in watersnakes
• Jason R. Warner (MS student): Comparative cold-hardieness strategies of liolaemid lizards living along an elevational gradient in the Andes of Argentina
• Beck A. Wehrle (MS student): Going green: the acquisition of fiber-fermenting microbes by hatchling green iguanas (Iguana iguana)
• Denita M. Weeks (MS student): Implications of global warming for the world's southernmost gecko
• Navasha Singh (undergraduate): The relationship between gut morphology and diet in lizards

Former MS Students

• Diana L. Andres (MS 2005): Consequences of diet switching for digestive function and the gut endosymbiont community for an herbivorous lizard
• Kamelia [Fallahpour] Algiers (MS 2004): The role of female breeding coloration in the behavior and mate selection of male leopard lizards (Gambelia wislizenii)
• Raymond A. Hernandez (MS 2009): Can omnivores be diet specialists? Adaptability of gut form and function in an omnivorous lizard
• Jennifer R. [Weist] Lancaster (MS 2005): Why do banded geckos band? Identifying the causes and benefits of diurnal aggregation in (Coleonyx variegatus)

Selected Publications

Espinoza, R. E. 2009. Western fence lizard (Sceloporus occidentalis). Pp. 234-237, in: Lizards of the American Southwest: A Photographic Fieldguide, L. L. C. Jones and R. E. Lovich (eds.). Rio Nuevo Press, Tucson, Arizona.

Espinoza, R. E. 2009. Mohave fringe-toed lizard (Uma scoparia). Pp. 278-281, in: Lizards of the American Southwest: A Photographic Fieldguide, L. L. C. Jones and R. E. Lovich (eds.). Rio Nuevo Press, Tucson, Arizona.

Espinoza, R. E. 2009. Western banded gecko (Coleonyx variegatus). Pp. 312-315, in: Lizards of the American Southwest: A Photographic Fieldguide. L. L. C. Jones and R. E. Lovich (eds.). Rio Nuevo Press, Tucson, Arizona.

Espinoza, R. E. and K. de Queiroz. 2008. Historical perspectives: Richard Emmett Etheridge. Copeia 2008:708-717. [pdf]

Abadala, C. S., A. S. Quinteros, and R. E. Espinoza. 2008. Two new species of Liolaemus (Iguania: Liolaemidae) from the Puna of northwestern Argentina. Herpetologica 64:458-471. [pdf]

Espinoza, R. E. and S. Quinteros. 2008. A hot knot of toads: aggregation provides thermal benefits to metamorphic Andean toads. Journal of Thermal Biology 33:67-75. [pdf]

Tracy, C. R. , K. E. Nussear, T. C. Esque, K. Dean-Bradley, C. R. Tracy, L. A. DeFalco, K. T. Castle, L. C. Zimmerman, R. E. Espinoza, and A. M. Barber. 2006. The importance of physiological ecology in conservation biology. Integrative and Comparative Biology 46:1191-1205. [pdf]

Lancaster, J. R., P. Wilson, and R. E. Espinoza. 2006. Physiological benefits as precursors of sociality: why banded geckos band. Animal Behaviour 72:199-207. [pdf]

Cruz, F. B., L. A. Fitzgerald, R. E. Espinoza, and Schulte, J. A. II. 2005. The importance of phylogenetic scale in tests of Bergmann's and Rapoport's rules: lessons from a clade of South American lizards. Journal of Evolutionary Biology 18:1559-1574. [pdf]

Tracy, C. R. , K. M. Flack, L. C. Zimmerman, R. E. Espinoza, and C. R. Tracy. 2005. Herbivory imposes constraints on voluntary hypothermia in lizards. Copeia 2005:12-19. [pdf]

Espinoza, R. E., J. J. Wiens, and C. R. Tracy. 2004. Recurrent evolution of herbivory in small, cold-climate lizards: breaking the ecophysiological rules of reptilian herbivory. Proceedings of the National Academy of Sciences, USA 101:16819-16824. [pdf]

Lobo, F. and R. E. Espinoza. 2004. Two new Liolaemus from the Puna region of Argentina and Chile: further resolution of purported reproductive bimodality in Liolaemus alticolor (Iguania: Liolaemidae). Copeia 2004:850-866. [pdf]

Hernandez, R. A. and R. E. Espinoza. 2004. Description of the female of the enigmatic lizard, Liolaemus heliodermis (Iguania: Liolaemidae). Herpetological Review 35:227-229. [pdf]

Espinoza, R. E. and F. Lobo. 2003. Two new species of Liolaemus lizards from northwestern Argentina: speciation within the northern subclade of the elongatus group (Iguania: Liolaemidae). Herpetologica 59:89-105. [pdf]

Cooper, W. E. Jr., J. J. Habegger, and R. E. Espinoza. 2001. Responses to prey and plant chemicals by three iguanian lizards: relationship to plants in the diet. Amphibia-Reptilia 22:349-362.

Scheltinga, D. M., B. G. M. Jamieson, R. E. Espinoza, and K. S. Orrell. 2001. Descriptions of the mature spermatozoa of the lizards Crotaphytus bicinctores, Gambelia wislizenii (Crotaphytidae), and Anolis carolinensis (Polychrotidae) (Reptilia, Squamata, Iguania). Journal of Morphology 247:160-171. [pdf]

Simandle, E. T., R. E. Espinoza, K. E. Nussear, and C. R. Tracy. 2001. Lizards, lipids, and dietary links to animal function. Physiological and Biochemical Zoology 74:625-640. [pdf]

Etheridge, R. and R. E. Espinoza. 2000. Taxonomy of the Liolaeminae (Squamata: Iguania: Tropiduridae) and a semi-annotated bibliography. Smithsonian Herpetological Information Service 126:1-64. [continuously updated on the web: Liolaemidae Website]

Espinoza, R. E., F. Lobo, and F. B. Cruz. 2000. Liolaemus heliodermis, a new lizard from northwestern Argentina with remarks on the content of the elongatus group (Iguania: Tropiduridae). Herpetologica 56:235-244.[pdf]

Schulte, J. A. II, J. R. Macey, R. E. Espinoza, and A. Larson. 2000. Phylogenetic relationships in the iguanid lizard genus Liolaemus: multiple origins of viviparous reproduction and evidence for recurring Andean vicariance and dispersal. Biological Journal of the Linnean Society 69:75-102. [pdf]

Halloy, M. and R. E. Espinoza. 1999-2000. Territorial encounters and threat displays in the Neotropical frog, Phyllomedusa sauvagii (Anura: Hylidae). Herpetological Natural History 7:175-180. [pdf]

Lobo, F. and R. E. Espinoza. 1999. Two new cryptic species of Liolaemus (Iguania: Tropiduridae) from northwestern Argentina: resolution of the purported reproductive bimodality of Liolaemus alticolor. Copeia 1999:122-140.[pdf]

Nussear, K. E., R. E. Espinoza, C. M. Gubbins, K. J. Field, and J. P. Hayes. 1998. Diet quality does not affect resting metabolic rate or body temperatures selected by an herbivorous lizard. Journal of Comparative Physiology B 168:183-189. [pdf/erratum]

Espinoza, R. E. and C. R. Tracy. 1997. Thermal biology, metabolism, and hibernation. Pp. 149-184, in: The Biology, Husbandry and Health Care of Reptiles. L. J. Ackerman (Ed.). Volume 1, Biology of Reptiles. T.F.H. Publications, Neptune City, New Jersey. [pdf]

Espinoza, R. E. and F. Lobo. 1996. Possible communal nesting in two species of Liolaemus lizards (Iguania: Tropiduridae) from northern Argentina. Herpetological Natural History 4:65-68. [pdf]

Courses

• Vertebrate Biology (BIOL 312/312L/392F) [Fall 2006 Curriculum]
  
  
• Herpetology (BIOL 512/512L/592E) [Spring 2007 Curriculum]
  
  
• Seminar in Ecology (BIOL 615) [Spring 2007 Flyer]
  
  
• Graduate Proseminar (BIOL 691) [Fall 2009 Curriculum]