Email: jonathan.richardson@yale.edu
Office: Greeley Laboratory, Room 127
Phone: (203) 432-5321
Fax: (203) 432-3929

EDUCATION

RESEARCH INTERESTS

During my last two years at Virginia I did a project investigating the phenotypic plasticity capabilities of the gray treefrog (Hyla chrysoscelis), a common species in the eastern half of the US. In the presence of predators, tadpoles of this species can develop a strikingly conspicuous morphology, with a deeper and brightly colored tail fin, which aids in predator avoidance. But shifting to this body-type unnecessarily (in the absence of predators) lowers tadpole survival. To look into this fitness trade-off, my primary question here focused on the reliability of hazard cues (to portend predation risk) that are used by developing tadpoles to accurately assess their risk, and induce such a conspicuous anti-predator phenotype. I found that tadpoles exhibited a clean graded phenotypic response to the available cues, corresponding to their relative reliability as indicators of a risk of predation. Most interesting, though, was that these tadpoles were able to respond to cues emitted when tadpoles of a different species were consumed, which has important implications for diffuse interspecific communication in the larger context of aquatic communities. The actual experiment was conducted at UVa's Mountain Lake Biological Station in the summer of 2003. For more details, see the link to the corresponding manuscript on the right.

Past research experience also includes boreal toad fire ecology in Glacier National Park, feline neurobiology at the University of Washington, chinook salmon management with the National Marine Fisheries Service, plant primary productivity trade-offs in water/nitrogen limited habitats, and salamander capture efficiencies in the field (UVa).

Here at Yale, I'm planning on following up on another project I was involved with at Virginia. Generally, I'm interested in metapopulation systems, and particularly in connectivity dynamics among subpopulations. The shifting mosaic of subpopulations, and the necessity of interactions between source and sink populations, should play a more significant role in our decision making process in conservation biology. I'm interested in doing a project that investigates not only the importance of these connections within metapopulations, but also their sensitivity to perturbations and habitat degradation. Amphibians are particularly amenable study organisms for this type of research due to their use of obligate breeding ponds, as well as migration distances and frequencies. Also, amphibians are presently experiencing a startling trend of species extinctions, with recent studies indicating that habitat loss and fragmentation are likely the threats of paramount concern. This makes it all the more essential to refine our understanding of amphibian population dynamics. More details to come...