Variations in Vocalization Frequency of Chachalacas in Chamela, Jalisco Mexico

The Western Mexico chachalaca (Ortalis poliocephala) is a large, frugivorous bird endemic to the tropical dry forest of western Mexico. They are very vocal, with a distinctive call that serves a variety of purposes, not all of which are understood, but can be used in territorial displays and as an alarm of danger. The call contains two motifs with the first consisting of two to four harsh notes gaining in volume and pitch. The second motif has considerable variation in the number of syllables (two to eight), but consists of three harsh notes increasing in pitch. Our objective was to investigate how the frequency of calling varied over the course of the day and habitat type. The research was conducted at the Estacion de Biologia Chamela in Jalisco, Mexico over four days in late March. We walked a 4.8 kilometer route through the forest in the morning and late afternoon and recorded each group we encountered for a ten minute period. Our route took us along the ridge and down in the arroyo. Meanwhile, we also recorded the number of calls heard from the field station itself. The data showed that O. poliocephala called almost exclusively between the times of 06:00 and 11:00. Habitat type did not seem crucial in determining location of groups. Understanding vocalization patterns helps give us an insight into the group dynamics of the birds and opens door for future research into the meaning behind the calls. For this presentation, Julia VanDerslice and Emily Reyer received a College of the Sciences Best Oral Presentation Award for 2014