The global crisis in amphibian conservation has created a need for new methods to assess population sizes and trends. I examine potential methods for assessing population trends of a small Central American poison dart frog, Oophaga pumilio (Anura: Dendrobatidae), in the Bocas Del Toro region of Panama where the frog is highly polymorphic and little is known about the ecology of individual populations. I pursued four lines of inquiry: 1) quantifying the changes in available habitat using satellite imagery, 2) measuring population densities for nine populations, 3) analyzing the potential for call surveys for population assessment, and 4) conducting experiments to identify factors limiting the populations. Analysis of satellite imagery for Normalized Difference Vegetation Index (NDVI) between 1986 and 1999 showed increases in habitat types associated with human development and losses in the amount of mature forest in all areas examined. Through the use of transects, I was able to assess population densities as well as relationship to edges for each of nine populations. Populations varied six-fold in density and in distribution related to forest edge. To explore the use of call surveys for population assessment, I conducted combined call and visual surveys. I found no relationship between call density and population density. Finally, I manipulated potential limiting factors such as food availability and rearing sites, identifying rearing sites as a limiting resource for these frogs. The results of this work provide important ecological information about this species such that managers may use these results to conserve at-risk populations of Oophaga pumilio through its range.
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