Depeine, C. D., Bernhard, D. E., Newman, J. D. 2007. Consistency of vocal behavior during brief separations in common marmosets. American Journal of Primatology 69(S1), 107. (30th Meeting of the American Society of Primatologists Scientific Program, Abstract #156)

Studies of the vocal behavior of captive nonhuman primates need to balance the requirement of maximizing the quality of the data collected with the desirability of minimizing the stress any procedures associated with data collection might impose on the subjects. Our studies of vocal behavior in common marmosets (Callithrix jacchus) have employed brief separations for recording and analyzing the vocalizations associated with this procedure. Typically, we separated animals from their family groups for 5-10 minute periods, but it has been unclear whether these brief separations represent inherently variable vocal behavior or are an accurate reflection of vocal behavior over longer time periods. To address this, we separated 28 marmosets, ranging in age from 1 month to 32 months, for 20 minute sessions and analyzed their vocal behavior in 5 minute blocks. The software programs ‘Raven’ and ‘Syrinx’ were used to display and annotate the files, MS Excel was used to tabulate the vocal output, and SPSS v13 was used for statistical analysis. Each vocalization was classified as one of eight call types and an analysis was made of call type variability across the 20-minute sessions. With few exceptions, calling behavior in the first 5 minutes was an accurate reflection of calling behavior across the entire session (Kolmogorov-Smirnov Test, p values ranged from 0.699–1.00 depending on the age group). This was true even of the youngest animals. This finding suggests that calling during 5-10 minute separations are adequate for depicting general calling behavior in this context.