We work on two related areas: (1) life history biology and (2) metamorphosis. 80% of animal species have a life history that includes a metamorphosis. We use surveys and experiments with amphibians that allow us to understand the relationship between metamorphosis and life history evolution.
We perform several kinds of studies but in particular we use (1) time-series collections of animals that allow us to elucidate life history parameters like growth rate, size/age at metamorphosis, and size/age at sexual maturation and (2) laboratory growth experiments with amphibian larvae wherein environmental variables that affect growth are manipulated and the outcome on timing and size at metamorphosis are observed.
Metamorphosis of
Eurycea wilderae
Larval Eurycea wilderae grown in the lab at different rates and different temperatures (top, 11 C; bottom 14 C). In this plethodontid salamander, cooler temperatures delay metamorphosis, but variable growth rates do not. (Beachy, 2018, Southeastern Naturalist)
Size-frequency distributions of larval (and metamorphosing, open blocks) Desmognathus quadramaculatus from the Black Mountains of North Carolina. These data are used to infer the duration of the larval period of this plethodontid salamander (2-3 years at this locality). (From Beachy and Bruce, 2003, Amphibia-Reptilia)
While lots of our questions require fieldwork, we also do work in the lab: growth experiments and morphological analyses of the salamanders and frogs that we grow or collect. Here, Cannon and Pacheco were caught doing gonadal inspections on their, respectively, Western Tiger Salamanders and axolotls.
We get requests to post/link to our videos of tigers salamanders in North Dakota that spend winters under the ice in ponds and lakes. Click this link to watch a sample.
