Use of vertical space by small mammals in gallery forest and woodland savannah in south-western Brazil

We examined the community composition and abundance of small mammals in the vertical strata of gallery forests and woodland savannahs in south-western Brazil. Captures were carried out during the winter and summer months of 2006/2007. Traps were set in three transect lines per habitat, with 10 capture stations on each line. Each station had three traps: on the ground, in the understorey (2-3 m in height), and in the canopy (8-10 m) in each physiognomy. With an effort of 3600 trap-nights, 11 species of small mammals were captured, which were distributed differently regarding the forest physiognomies and utilisation of vertical strata. The species showed a high degree of habitat segregation in the two physiognomies, with only the climbing-rat Rhipidomys macrurus found in both habitats. The correspondence analysis revealed that Caluromys philander occurred mostly in the canopy; Cryptonanus agricolai, Marmosa murina, and Oecomys bicolor in the understorey; and Gracilinanus agilis and Nectomys rattus on the ground. The utilisation of traps in different strata increased species richness in the Cerrado biome, showing that the small-mammal community is distributed along the vertical complexity of the forest and even in different physiognomies, enabling more species to coexist.