October 4 2012

5:00 pm 154 BSRB

EcoEvoPub Series

Graduate Student Presentations


Department of Ecology and Evolutionary Biology

“Biogeography of the Marmosets and Tamarins”

The Callitrichidae are a family of Platyrrhine monkeys with greater than 50 taxa with distributions in Central and South America. Previous phylogenetic studies of the group have neglected to consider the species relationships within a geographic context. Here we consider the phylogenetic relationships and biogeography of the family using a species tree constructed from a concatenation of ten genes. We implemented a Bayesian discrete-states model of diffusion in BEAST for 40 taxa to determine the most likely pattern of invasion across South America. Our data show that sister taxa are grouping geographically within the same or in adjacent subregions. Also, our study supports an origin of the Callitrichid ancestor in the western Amazon and two major invasions of the Atlantic forest region from the Amazon at approximately 13MYA and 6MYA. We have also found that multiple instances of re-invasion and counter-invasion throughout the group's history explain current patterns of sympatry among species. Finally, our geographic data, along with morphological and phylogenetic data, lends support to certain taxonomic delineations including the splitting of the genus Saguinus into two genera.

Department of Ecology and Evolutionary Biology

“The Function of Duetting in a Neotropical Passerine, the White-Breasted Wood Wren"”

Birds sing to attract prospective mates and to deter potential rivals from their territories. Only males sing in most temperate passerine species, however female song is common in the tropics, and in some species, pairs coordinate their songs into vocal duets. I will discuss the vocal repertoire and duetting behavior of the white-breasted wood wren (Henicorhina leucosticta) from a lowland rainforest in Southern Mexico. I evaluated duetting through dual–speaker playback experiments that realistically simulated duetting intruders using an innovative wireless sensor array developed in our lab to localize the position of multiple interacting singers from recordings of their vocalizations. I will show support for cooperation as the function of duetting rather than a conflict between the sexes and discuss some implications for the nature of this species pair bond.

THURSDAY, October 4, 2012











































































































































































































































































































































































































































































































































































































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