Activity pattern of medium and large sized mammals and density estimates of Cuniculus paca (Rodentia: Cuniculidae) in the Brazilian Pampa

• Published in: Brazilian journal of biology Vol. 78; no. 4; pp. 697 - 705
• Main Authors: Leuchtenberger, C, de Oliveira, Ê S, Cariolatto, L P, Kasper, C B
• Format: Journal Article
• Language: English
• Published: Brazil Instituto Internacional de Ecologia 01-11-2018
• Subjects: abundância; Activity patterns; Animals; armadilha fotográfica; atividade circadiana; Biological Evolution; BIOLOGY; Brazil; Cameras; campos sulinos; Capture-recapture studies; Cerdocyon thous; Circadian Rhythm - physiology; Circadian rhythms; Conepatus chinga; Crepuscular; Cuniculus paca; Ecological monitoring; Ecology; Ecosystems; Endangered & extinct species; Estimates; Forests; Grasslands; Human influences; Hydrochoerus hydrochaeris; Mammals; Mammals - physiology; mamíferos terrestres; Mazama gouazoubira; Nocturnal; Population Density; Predation; Residential density; Riparian environments; Riparian forests; Skin spot; Brazil; Rio Grande do Sul Brazil; abundância; terrestrial mammals; campos sulinos; abundance; atividade circadiana; circadian activity; armadilha fotográfica; camera trap; south grasslands; mamíferos terrestres
• ISSN: 1519-6984; 1678-4375; 1678-4375
• DOI: 10.1590/1519-6984.174403

Between July 2014 and April 2015, we conducted weekly inventories of the circadian activity patterns of mammals in Passo Novo locality, municipality of Alegrete, southern Brazil. The vegetation is comprised by a grassy-woody steppe (grassland). We used two camera traps alternately located on one of four 1 km transects, each separated by 1 km. We classified the activity pattern of species by the percentage of photographic records taken in each daily period. We identify Cuniculus paca individuals by differences in the patterns of flank spots. We then estimate the density 1) considering the area of riparian forest present in the sampling area, and 2) through capture/recapture analysis. Cuniculus paca, Conepatus chinga and Hydrochoerus hydrochaeris were nocturnal, Cerdocyon thous had a crepuscular/nocturnal pattern, while Mazama gouazoubira was cathemeral. The patterns of circadian activity observed for medium and large mammals in this Pampa region (southern grasslands) may reflect not only evolutionary, biological and ecological affects, but also human impacts not assessed in this study. We identified ten individuals of C. paca through skin spot patterns during the study period, which were recorded in different transects and months. The minimum population density of C. paca was 3.5 individuals per km2 (resident animals only) and the total density estimates varied from 7.1 to 11.8 individuals per km2, when considering all individuals recorded or the result of the capture/recapture analysis, respectively.