kwarken@bu.edu

Animal Behavior Behavioral Ecology and Sociobiology Developmental Biology Ecology and Conservation Biology Tropical Ecology

Karen Warkentin
Assistant Professor of Biology
Ph.D., University of Texas at Austin, 1998

Behavioral ecology, evolutionary biology, herpetology, tropical biology

Research in my laboratory examines developing organisms in an ecological context. A central goal of the research is to understand why and how embryos hatch when they do. We are particularly interested in the ability of embryos to facultatively alter the developmental stage at which they hatch, in response to changing risks in the egg and post-hatching environments.

Our study organisms are amphibians and their enemies, and research in my lab includes both tropical and temperate components. In the neotropics, my students and I study leaf-breeding treefrogs, including the red-eyed treefrog Agalychnis callidryas and its congeners as well as the hourglass or 'pantless' treefrog Hyla ebraccata . Red-eyed treefrogs hatch up to 30% prematurely in response to at least 4 different egg stage risks. Our work addresses how the embryos detect these risks, and how they decide when to hatch, as well as the larger consequences of hatching stage in different environments. In New England, we study salamanders and frogs that breed in vernal pools, focusing on pathogen-induced early hatching and its consequences.

Hatching is an ecologically important developmental and life history event. It changes vulnerability to predators and physical stresses, as well as resource use. Because hatching occurs during a period of rapid development, small changes in hatching stage may have dramatic effects on hatchling morphology and behavior. Eggs and young larvae often suffer high mortality, and the timing of hatching profoundly affects survival. We want to understand the developmental and physiological basis of hatching timing and hatching plasticity, the selective forces acting on hatching stage, and the evolutionary history of hatching stage variation.

Work in my lab integrates ideas and techniques from ecology, behavior, physiology, development and evolutionary biology. I welcome applications from students interested in evolutionary or mechanistic questions addressing the interplay between development, behavior and ecology, in amphibians and other organisms.

Gomez-Mestre, I., J.J. Wiens, and K.M. Warkentin, in press. Evolution of adaptive plasticity: risk-sensitive hatching in neotropical leaf-breeding treefrogs (Agalychnis: Hylidae). Ecological Monographs.

Gomez-Mestre, I. and K.M. Warkentin, 2007. To hatch and hatch not: similar selective trade-offs but different responses to egg predators in two closely related, syntopic treefrogs. Oecologia 153, 197-206. Click here to view PDF file.

Warkentin, K.M., 2007. Oxygen, gills, and embryo behavior: mechanisms of adaptive plasticity in hatching. Comparative Biochemistry and Physiology A 148, 720-731. Click here to view PDF file.

Gomez-Mestre I., Warkentin K. M. In press. To hatch and hatch not: similar selective trade-offs but different responses to egg predators in two closely related, syntopic treefrogs. Oecologia

Warkentin K. M., Caldwell M. S., Siok T. D., D'Amato A. T. , McDaniel J. G. 2007. Flexible information sampling in vibrational assessment of predation risk by red-eyed treefrog embryos. Journal of Experimental Biology 210, 614-619. Click here to view PDF file.

Gomez-Mestre, I., Touchon, J.C., Warkentin, K.M., 2006. Amphibian embryo and parental defenses and a larval predator reduce egg mortality from water mold. Ecology 87, 2570-2581. Click here to view PDF file.

Touchon, J.C., Gomez-Mestre, I., Warkentin, K.M., 2006. Hatching plasticity in two temperate anurans: responses to a pathogen and predation cues. Canadian Journal of Zoology 84, 556-563. Click here to view PDF file.

Warkentin, K.M., Caldwell, M.S., McDaniel, J.G., 2006. Temporal pattern cues in vibrational risk assessment by red-eyed treefrog embryos, Agalychnis callidryas. Journal of Experimental Biology 209, 1376-1384. Click here to view PDF file.

Vonesh, J.R. & K.M. Warkentin.   2006. Opposite shifts in size at metamorphosis in response to larval and metamorph predators. Ecology. 87(3):556-562. Click here to view PDF file.

Warkentin, K. M., C.R. Buckley & K.A. Metcalf. 2006. Development of red-eyed treefrog eggs affects efficiency and choices of egg-foraging wasps. Animal Behaviour 71, 417-425.Click here to view PDF file.

Warkentin, K. M., I. Gomez-Mestre & J.G. McDaniel. 2005. Development, surface exposure, and embryo behavior affect oxygen levels in eggs of the red-eyed treefrog, Agalychnis callidryas . Physiological and Biochemical Zoology 78: 956-966. Click here to view PDF file.

Warkentin, K.M. 2005. How do embryos assess risk? Vibrational cues in predator-induced hatching of red-eyed treefrogs. Animal Behaviour 70: 59-71. Click here to view PDF file.

Warkentin, K.M. 2002. Hatching timing, oxygen availability, and external gill regression in the tree frog, Agalychnis callidryas . Physiological and Biochemical Zoology 75:155-164. Click here to view PDF file.

Warkentin, K.M., C.C. Currie & S.A. Rehner. 2001. Egg-killing fungus induces early hatching of red-eyed treefrog eggs. Ecology 2860-2869. Click here to view PDF file.

Warkentin, K.M. & R.J. Wassersug. 2001. Does prostaglandin regulate external gill loss in anurans? Journal of Experimental Zoology 289: 366-373.

Warkentin, K.M. 2000. Environmental and developmental effects on external gill loss in the red-eyed treefrog, Agalychnis callidryas . Physiological and Biochemical Zoology 73: 557-565. Click here to view PDF file.

Warkentin, K.M. 2000. Wasp predation and wasp-induced hatching of red-eyed treefrog eggs. Animal Behaviour 60: 503-510. Click here to view the PDF file.

Warkentin KM. 2002. Hatching timing, oxygen availability, and external gill regression in the tree frog, Agalychnis callidryas. Physiol Biochem Zool. Mar-Apr;75(2):155-64.

Warkentin, K.M., C.C. Currie & S.A. Rehner. 2001. Egg-killing fungus induces early hatching of red-eyed treefrog eggs. Ecology, 82:2860-2869.

Warkentin, K.M. & R.J. Wassersug. 2001. Does prostaglandin regulate external gill loss in anurans? Journal of Experimental Zoology 289: 366-373.

Warkentin, K.M. 2000. Environmental and developmental effects on external gill loss in the red-eyed treefrog, Agalychnis callidryas. Physiological and Biochemical Zoology 73: 557-565.

Warkentin, K.M. 2000. Wasp predation and wasp-induced hatching of red-eyed treefrog eggs. Animal Behaviour 60: 503-510.

Warkentin, K.M. 1999. Effects of hatching age on development and hatchling morphology in the red-eyed treefrog, Agalychnis callidryas. Biological Journal of the Linnean Society 68: 443-470.

Warkentin, K.M. 1999. The development of behavioral defenses: a mechanistic analysis of vulnerability in red-eyed tree frog hatchlings. Behavioral Ecology 10: 251-262.

Warkentin, K.M. 1995. Adaptive plasticity in hatching age: A response to predation risk trade-offs. Proceedings of the National Academy of Sciences 92: 3507-3510.

Ryan, M.J., K.M. Warkentin, B.E. McClelland & W. Wilczynski. 1995. Fluctuating asymmetries and advertisement call variation in the cricket frog, Acris crepitans. Behavioral Ecology 6 (2):124-131.

Warkentin, K.M. 1992. Microhabitat use and feeding rate variation in green frog tadpoles (Rana clamitans). Copeia 1992 (3):731-740.

Warkentin, K.M. 1992. Effects of temperature and illumination on feeding rates of green frog tadpoles (Rana clamitans). Copeia 1992 (3):725-730.

Questions and comments are always welcome.
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This document was last modified on January 16, 2008.