Use of space by the Neotropical caviomorph rodent Thrichomys apereoides (Rodentia: Echimyidae)

ABSTRACT

The objective of this study was to investigate some parameters of the space use by individuals in a population of the hystricognath rodent Thrichomys apereoides (Lund, 1839), using the spool-and-line tracking technique. This technique is useful for investigating characteristics of habitat use by individuals since it allows the mapping of the places where the individuals move. We evaluated three parameters of space use by 34 individuals of T. apereoides 1) The daily home range (DHR) or the area used by individuals in their daily activities, 2) the distance moved on the leaf litter, and 3) the distance moved above ground using twigs, logs and rocks. The analysis of space use on such a small scale allows a better understanding of how individuals perceive and use the available space. The significant effect of age on DHR and the effect of the sex on the movements above ground were observed. Adult males had larger DHRs than adult females and subadults, and adult females showed the lowest displacement above ground. A statistically significant effect of the sex and seasonal period and the interaction between them was also observed on the size of DHRs of adults. During the dry season, females had lower DHRs than males and both females and males moved less on leaf litter in this season. There was no seasonal effect on the movement of males and females above ground, as well as no significant effect of age and sex on the movement of the individuals on leaf litter. We found that individuals responded differently to some aspects of the habitat structure and concluded that the pattern of movement is influenced by the sex and the age of the individuals and may vary according to ecological conditions.(AU)