Movement distances for four small mammals in two Atlantic forests fragments, Southern Brazil

Daniela Oliveira De Lima,Luana Gabriele Arenhart Braun,Fabrício Luiz Skupien,Jady De Oliveira Sausen,Daniele Pereira Rodrigues

doi:10.3897/neotropical.16.e59669

Abstract

Animal movement has an important role in individual performance, species reproduction, population demography, and conservation, especially in fragmented landscapes. The distance moved by an individual may vary depending on individual needs, such as the search for food resources and sexual partners. Here we investigated which factors affect the distances between successive captures (hereafter DSC) for Akodon montensis, Oligoryzomys nigripes, Sooretamys angouya, and Didelphis albiventris. This study was conducted from April 2015 to October 2016 in two fragments in the south of Atlantic Forest biome through capture, mark and recapture technique. DSC was analyzed using Generalized Linear Models with Poisson distribution where the independent variables were sex, whether the animal was active or not in terms of reproduction, body weight, and climatic season. The mean DSC was greater for D. albiventris (44.6 ± 28.8 m), followed by S. angouya (31.9 ± 25.7 m), O. nigripes (25.8 ± 22.5 m) and A. montensis (18.9 ± 22.0 m). Males of all species moved larger DSC than females. Considering the rodents, reproductive animals also moved larger DSC than non-reproductive animals. Sex may have masked the effect of body weight, as males tend to be larger than females. Climatic effects were tested for A. montensis and O. nigripes, however, with diverse effects.

Highlights

Animal movement patterns and distances vary depending on individual needs
There is a great variety of methodological approaches to study animal movement, ranging from the most sophisticated and data demanding methods, such as the kernel estimates of home range (Fleming et al 2015), to more simplistic methods, such as the distances moved between successive captures (DSC; for more explanation on this method see Püttker et al 2006 and Püttker et al 2012)
Considering the other two rodents, even though O. nigripes (27 ± 8 g), the smaller species, had greater DSC than A. montensis (35 ± 8 g), the body size difference among these species is very small and it is probably second in place regarding this DSC difference

Summary

Introduction

Animal movement patterns and distances vary depending on individual needs. For instance, climatic seasons will affect food resources (Naxara et al 2009) and during food shortage periods, animals might have to move longer distances to find food (Winker et al 1995; Loretto and Vieira 2005); and the same happens for animals with bigger corporal size, that need more food resources (Lima et al 2016). We recorded the specific position of each trapping station, so, when an individual was recaptured (within the same sampling season), we could measure the minimum distance traveled between these two successive captures, the DSC.

Results

Conclusion