Construction of arboreal nests by brown-nosed coatis, Nasua nasua (Carnivora: Procyonidae) in the Brazilian Pantanal

The construction of arboreal nests is rare among mammals in the order Carnivora. However, coatis (Procyonidae: Nasua Storr, 1780) build arboreal nests that are used for resting or birthing. Here we describe Nasua nasua (Linnaeus, 1766) nests located during a telemetry study of coatis in the Brazilian Pantanal. Coati nests were all "bird-like", that is, open nests having a semispherical shape. Nests were constructed of twigs, branches, and lianas sometimes interlaced with leaves. Nest volume was 30-50 cm³ and average nest height was approximately 9.5 m. Nests were found in open "cerrado" vegetation, along forest edges, or in interior "cordilheiras" forest. The reasons why coatis build such nests are unclear, but may relate to inter or intraspecific competition for nesting sites, litter size, thermoregulation, and predation avoidance.