Graduate Student
Virginia Tech
Contact Information:
4098 Derring Hall
Mail: Dept. of Biological Sciences (0406)
Virginia Polytechnic Institute and State University
Blacksburg, VA 24061
Email: jcastner@vt.edu
Current Research: I am a graduate student in Dr. Ignacio Moore's lab examining the role of cultural divergence in population divergence in two allopatric populations of Rufous-Collared Sparrows (Zonotrichia capensis) in Ecuador. It is suggested that localized song-dialects facilitate assortative mating, and thereby restrict gene flow among populations. In some allopatric bird populations, songs drift into different dialects. Lack of dialect recognition, limits gene flow among populations, acting as a primary reproductive isolating mechanism. A current hypothesis regarding tropical bird speciation states that when populations divide geographically, they assume asynchronous breeding cycles due to local abiotic factors, experience song drift, and subsequently rapid genetic divergence occurs. This hypothesis predicts that upon secondary contact, birds would not mate due to differences in reproductive preparedness and lack of recognition or preference. However, an integral piece of this hypothesis is uncertain: upon secondary contact, would the birds recognize each other and interbreed or would they mate assortatively? To test this idea I perform song trials with playback experiments and examine female recognition and preference of foreign dialects. For each trial, I record the females’ behavioral response and quantify female responsiveness to male song, using a copulation solicitation assay.
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| Rufous-Collared Sparrow (Zonotrichia capensis) | Field site in Papallacta, Ecuador | Playback trials |
| Hawaii | Central America | Alaska |
Hawaii: Palia Restoration Project. A conservation project for the endangered Palila (Loxioides bailleui) bird.
| Julie with Palila | Mauna Kea's shadow | Ray and Julie banding |
Central America: examined agroecosystems and the affect on avian communities by comparing the fitness of Thryothorus wrens in Nicaragua.
| Thryothorus maculipectus | Long-tailed Manakin | Santos, Ulda, Yasser (host family) |
Juneau, Alaska: performed all aspects of mist-netting, parasite sampling, nest searching, behavioral observations, and stream occupancy of American Dippers (Cinclus mexicanus).
American Dipper (Cinclus mexicanus) |
Ray nest searching | Juneau |
Links:
"Viva la evolucion!" |
