Friday, September 21, 2012 4:00 p.m. in ETC 4.150
Dr. Bret Pasch
Section of Integrative Biology
The University of Texas at Austin
Many animals use long-distance acoustic signals to advertise their presence to a network of potential mates and competitors. A rich tradition of studies on acoustic communication in birds, anurans, and insects has provided important insights into disparate disciplines of biology through integration of proximate and ultimate levels of analysis. Here, we synthesize data on vocal ontogeny, hormonal control, and the adaptive function of Neotropical singing mouse (Scotinomys) vocalizations in an ecological context. Neotropical singing mice are diurnal insectivorous rodents that inhabit montane cloud forests throughout Central America. Adult males of two species commonly produce a rapid series of notes that sweep from ~ 43 to 14 kHz. I describe how vocalizations develop from pup isolation calls, how sex differences in singing arise during puberty and are modulated by androgens, and how vocalizations are used in mate attraction and male-male aggression. Between species, interspecific communication reflects underlying dominance interactions and contributes to competitive exclusion along altitudinal gradients. Accordingly, the auditory tuning of mouse brains differs between sympatric and allopatric populations to accommodate the ecological salience of song. Altogether, Neotropical singing mice are emerging as important species that permit comparisons to communication systems in traditionally more tractable taxa.