Darwin's finches are a useful system in which to examine the interplay of ecology, morphology, and evolution. The PI and collaborators have described a population of the medium ground finch, Geospiza fortis, that possesses a bimodal distribution of beak size, i.e., the population consists of large beaked "morphs" and small beaked "morphs" with very few intermediate beak morphs. Both bite force abilities and song features differ between large and small morphs, and these differences are in the direction predicted by models of how the beak functions in feeding and song production. The main goal of the proposed research is to determine if large beaked morphs and small beaked morphs mate only with their own kind to the exclusion of the other morph. If so, this mating pattern may represent an example of sympatric speciation in progress. Banded birds will be observed for mating behavior and pair formation in the field and paternity tests will be conducted to determine if like-beaked birds are mating with each other and not with the other morph. The final goal of this proposal will be to experimentally test female preferences for the songs of males with similar beak size to determine if specific courtship rituals are unique for each morph.
Broader Impacts The proposed research will provide training in evolutionary biology for the Co-PI and aid in the completion of her dissertation research. All dissertation chapters will be submitted for publication in peer reviewed journals, and the results of all work will be disseminated to the public. Both the Co-PI and one field assistant will be trained in field observation, bird banding, and general field sampling techniques. In addition, the Co-PI will also learn techniques for DNA analysis and paternity assignment. Work will be conducted under permits through the Charles Darwin Research Station and the Galapagos National Park Service, and all research results will be provided to those sources for educational purposes. In addition, our results will provide information on the breeding biology of a protected species that can be used by the Galapagos National Park Service when drafting conservation policies.
