Here we present an experiment investigating whether visual and acoustic predator cues elicit different vocal reactions in black-fronted titi monkeys (Callicebus nigrifrons). The dataset includes information on the vocal reactions of six groups of wild titi monkeys to visual models or playbacks of vocalizations of raptor or felid. The dataset characterizes each group’s vocal reactions using sequence parameters known to reliably encode predatory events in this species. The dataset provides insights into the semantic capacities of titi monkeys and highlights the importance of using both visual models and predator vocalization playbacks for fine-grained analyses of prey communication systems.

The data consists of the vocal reactions of 47 individual titi monkeys in response to predator presentations. We used the vocal repertoire established by Cäsar et al. (2012a) to code the vocal reactions. We labelled each call emitted within the first 20 s of each experiment and extracted seven sequence parameters from each vocal reaction. These variables include the type of the first call emitted, the proportion of A-calls, the proportion of B-calls, the number of calls emitted within the first 20 s, the total duration of the vocal reaction, whether the group emitted loud vocalizations, and the proportion of responding individuals. We also coded the contextual parameters, including the social parameters and experimental parameters, such as predator type, location of the predator, and experimental paradigm.

Table 1: Sequence Parameters Extracted from Vocal Reactions of Titi Monkeys in Response to Predator Presentations

Figure 1: Spectrogram of vocal reactions in response to predator presentations showing three call types (a, b, and c) in subplots a, b, and c, respectively.

The data description includes the following key information:

• Type of data: vocal reactions of titi monkeys to predator presentations
• Format of the data: numerical data in the form of sequence parameters
• Data structure: seven sequence parameters extracted from each vocal reaction, including the type of the first call emitted, the proportion of A-calls, the proportion of B-calls, the number of calls emitted within the first 20 s, the total duration of the vocal reaction, whether the group emitted loud vocalizations, and the proportion of responding individuals

We used the vocal repertoire established by Cäsar et al. (2012a) to code the vocal reactions and extracted seven sequence parameters from each vocal reaction. We also coded the contextual parameters, including the social parameters and experimental parameters.

We found that titi monkeys’ vocal reactions varied with the predator species but also with the experimental paradigm. While vocal reactions to raptor vocalizations and models were similar, felid vocalizations elicited heterogeneous, different reactions from that given to felid models.

The findings suggest that titi monkeys’ vocal reactions vary with the predator species but also with the experimental paradigm. While vocal reactions to raptor vocalizations and models were similar, felid vocalizations elicited heterogeneous, different reactions from that given to felid models. This may be due to a lack of learning opportunities for titi monkeys regarding felid vocalizations, as felids tend to be silent predators. The dataset provides insights into the semantic capacities of titi monkeys and highlights the importance of considering the experimental paradigm in predator presentation experiments.

1. Cäsar C, Byrne R, Young RJ, Zuberbühler K (2012a) The alarm call system of wild black-fronted titi monkeys, Callicebus nigrifrons. Behav Ecol Sociobiol 66:653–667. https: doi. org/ 10. 1007/ s00265- 011- 1313-0