Table 1.
Mean ± standard deviation (SD) of acoustic parameters measured in spotted paca vocalizations.
Percentage of notes correctly attributed to each call type in the cross validation. The N corresponds to the number of emissions analyzed in each category/number of individuals from which individual calls were selected. The centroids show the spacing of different call types of spotted paca in a two-dimensional signal space defined by the first two discriminant functions (DF1 and DF2). The values in bold indicate the correlation coefficients of the variables that most contributed to the discriminant functions (DF1 and DF2).
Fig 1.
Spectrograms and time series of spotted paca vocalizations.
The arrows in the first roar vocalization (box a) indicate five formants. The box f shows combinations of sounds between roar and groan calls, and the arrows (1st and 2nd) of this box indicate the groan and roar calls, respectively.
Table 2.
Description of context and possible communicative function of the vocalizations of spotted paca associated with age (A: adult and J: juveniles) and sex (M: male and F: female).
Fig 2.
Dendrogram of similarity according to acoustic parameters of five different combinations (C1-C5) of roar (A) and groan (B). C1 (BA), C2 (ABABAB), C3 (ABA), C4 (ABAB), C5 (ABABA). The letters A and B correspond to the sequences of roar (A) and groan (B) appeared in each combination. Hierarchical clustering with Ward’s method was used to construct the dendrogram. Height represents cophenetic distance (dissimilarity) between the combinations. The dotted line represents the automatic truncation, leading to three combination calls of roar and groan.
Table 3.
Descriptive data for anatomical and acoustic variables of adult spotted paca (N = 4) used in formant analysis.
Fig 3.
Topology of the species of caviomorph rodents used in this study.
Fig 4.
The relationship between standardized independent contrasts of log10 vocal repertoire size and standardized contrasts of log10 group size of seven caviomorph rodent species.
The linear regression follows the equation: Standardized contrasts of log10 group size = 0.27 + 1.59*Standardized contrasts of log10 vocal repertoire size (F1, 4 = 10.41; R2 = 0.72; P = 0.03). Gray lozenge indicates the independent contrasts of the original seven caviomorph species, while black circle is the virtual position of the spotted paca based on the equation considering only its adult acoustic repertoire size (N = 6) determined in this study.
Table 4.
Data of the seven caviomorph species used to analyze the relationship between group size and the number of vocal types.