Identification of mammals from an Atlantic Rainforest remnant using the microstructure of guard hairs of predators and prey

Abstract

The microscopic identification of mammal guard hairs is a widely used tool to improve qualitatively and quantitatively the recognition of prey and predator hair found in scats, gut contents, and pellets. To identify hair found in carnivore feces, cuticular and medullary diagnostic features of guard hairs of 11 carnivore species (Carnivora: Mammalia) and 50 mammalian prey species were analysed and illustrated. Species of four families of carnivores have been identified: Cerdocyon thous (Canidae) presented anisocytic medulla with straight margins and a rhomboid cuticle; Nasua nasua and Procyon cancrivorus (Procyonidae) also with straight margins in the medulla, but with a waved pattern in its cuticle; Lontra longicaudis, Eira barbara and Galictis cuja (Mustelidae) with waved margins in the medulla; finaly, Puma concolor, P. yagouaroundi, Leopardus pardalis, L. wiedii and L. tigrinus (Felidae) presented trabecular medulla with fringed margins. The diagnostic features of the eleven carnivore species are also listed, making possible identification from fecal samples. Considering the prey, 44 species were identified to specific level and three pairs of species remained indistinguished. Specimens of Chiroptera, Pilosa and Cingulata presented guard hair devoid of medulla. In all other families the medulla is present and continuous, with the exception of Cebidae (Primates), Tapiridae (Perissodactyla) and Erethyzontidae (Rodentia) were it is descontinuous. In general, cuticular characters are most useful for diagnosis of species, while medullar characters are diagnostic for families and orders.