Abstract

SHEPHERD, John D.  and  DITGEN, Rebecca S.. Human use and small mammal communities of Araucaria forests in Neuquén, Argentina. Mastozool. neotrop. [online]. 2005, vol.12, n.2, pp.217-226. ISSN 0327-9383.

Small mammals were sampled in five closed, humid, Araucaria araucana forests that differed in the degree of anthropogenic disturbance in southwestern Neuquén province. Nine species were captured in 3416 trap nights. Abrothrix longipilis and Oligoryzomys longicaudatus made up 88% of all captures. Small mammal relative abundance was 52 times higher where grazing was absent compared to a site with intense grazing pressure. Seed predation, primarily by livestock and feral exotic mammals, varied from 59.7% to 15.1% of marked seeds per day. Small mammal community productivity and composition were correlated with understory structure (Mantel test, r = 0.529, p = 0.04), and with rates of seed predation (r = -0.91, n = 4, p = 0.08). Forests with less complex understories had fewer captures and lower mammal diversity. Exotic large mammals appear to affect native small mammals by simplifying the structure of the forest understory and by competing for seeds. Four native species (Abrothrix longipilis, Oligoryzomys longicaudatus, Chelemys macronyx, and Irenomys tarsalis) ate Araucaria piñones. Anthropogenic changes in small mammal communities indicate that management of feral and domestic mammals needs to be a prominent part of the conservation of these majestic forests.

Keywords : Araucaria araucana; Exotic species; Human impact; Seed predation; Small mammals.

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