Rebounding amphibian populations in a Bd enzootic landscape The decline of amphibians due to the pathogenic fungus Batrachochytrium dendrobatidis (Bd) has been well documented in Latin America. In some regions entire groups of frogs were lost and overall numbers were driven astonishingly low. Some, like the Isthmohyla rivularis in the photo, were assumed extinct. However, recent reports have suggested that some species are coming back from the brink of extinction, being found in areas where they were assumed extinct. These reports are coming from Australia, North America and Latin America. My project will examine these rebounding populations in Costa Rica, Panama and Peru to understand why certain species are rebounding and how they are able to do so in a habitat where Bd is still prevalent. My research will have several components:
Dynamics of rebounding populations
Population genetics of rebounding populations
Individual susceptibility to Bd
Predicting sites for possible rebounding populations
This research will help with understanding how populations and communities react to perturbations in long-term situations and may help inform current ex-situ conservation measures on future steps. Additionally, it is of great importance to helping predict how the newly discovered B. salamandrivorans may affect salamander populations worldwide.
Amphibian community structure post-decline Since those initial declines due to Bd were documented (some more that 20 years ago) little attention has been paid to how the amphibian communities have continued to change. The large scale declines of multiple species undoubtedly left open niches, niches that can be filled by those species that did not experience major die offs. The core of this research is attempting to understand community structure before, during, and post-major Bd declines and how changes in this structure may effect the environment.
Amphibians in a human dominated landscape There are few (if any) places left in the world without some anthropogenic influence. My master's research at Yale F&ES (w/David Skelly) focused on examining how populations Wood Frogs (Rana sylvatica) and Spotted Salamanders (Ambystoma maculatum) interact with urbanization. As cities and their suburbs continue to grow numerous habitat fragments are created; some as small as an isolated pond to small patches of remaining forest, to areas still connected to more contiguous habitat. Understanding what factors effect the persistence of species within these habitats and along this urbanization gradient allows us to make more informed decisions about land use and conservation measures in a human dominated landscape.
Oviposition site choice in anurans The traditional view of amphibian breeding behavior involved a dump and run strategy where the parents would lay eggs in any available water source and leave, providing no parental care. This is, in fact, far from true. There is an incredible diversity of parental care in amphibians. My undergraduate research at UConn (w/ Mark Urban) focused on species that seemingly had no parental care; the pond breeding Gray Tree Frog (Hyla versicolor). The theory of oviposition site choice suggests that adults may actually choose sites to lay their eggs based on factors that affect fitness (by tadpole survival). My study examined how Hyla versicolor chose between varying concentrations of predators and competitors and how these choices would effect their fitness.