Daily Movements and Microhabitat Selection of Hantavirus Reservoirs and Other Sigmodontinae Rodent Species that Inhabit a Protected Natural Area of Argentina.

Abundance, distribution, movement patterns, and habitat selection of a reservoir species influence the dispersal of zoonotic pathogens, and hence, the risk for humans. Movements and microhabitat use of rodent species, and their potential role in the transmission of hantavirus were studied in Otamendi Natural Reserve, Buenos Aires, Argentina. Movement estimators and qualitative characteristics of rodent paths were determined by means of a spool and line device method. Sampling was conducted during November and December 2011, and March, April, June, October, and December 2012. Forty-six Oxymycterus rufus, 41 Akodon azarae, 10 Scapteromys aquaticus and 5 Oligoryzomys flavescens were captured. Movement patterns and distances varied according to sex, habitat type, reproductive season, and body size among species. O. flavescens, reservoir of the etiologic agent of hantavirus pulmonary syndrome in the region, moved short distances, had the most linear paths and did not share paths with other species. A. azarae had an intermediate linearity index, its movements were longer in the highland grassland than in the lowland marsh and the salty grassland, and larger individuals traveled longer distances. O. rufus had the most tortuous paths and the males moved more during the non-breeding season. S. aquaticus movements were associated with habitat type with longer distances traveled in the lowland marsh than in the salty grassland. Hantavirus antibodies were detected in 20% of A. azarae and were not detected in any other species. Seropositive individuals were captured during the breeding season and 85% of them were males. A. azarae moved randomly and shared paths with all the other species, which could promote hantavirus spillover events.

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

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.

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

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)

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

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.