Trophic segregation of small carnivorans (Carnivora: Mustelidae and Mephitidae) from the southern cone of south America

Abstract

Remarkable adaptations in the Carnivora have evolved as a way of dealing with feeding competition, accen- tuating hypocarnivorous or hypercarnivorous morphotypes. The Carnivora is a highly successful order with 47 living species in South America. Their history in South America is recent, and includes few lineages that arrived before the Pana- manian bridge was completed (procyonids), and others that arrived later (felids, mephitids). Here, we evaluated the trophic segregation of small carnivorans ( Conepatus chinga , Galictus cuja , Lontra provocax , Lyncodon patagonicus , and the intro- duced Neovison vison ) from southern South America, using a geometric morphometric approach, i.e., Principal Component and Canonical Variate Analysis, to study shape variations and t -tests to study size variation. We also performed Canonical Phylogenetic Ordination to study the association between shape, size, diet, and phylogeny. We identified C. chinga as the most hypocarnivorous member of the guild, G. cuja , L. patagonicus ,and N. vison as hypercarnivores, with L. provocax in an intermediate position. Semiaquatic habits seg- regate Lontra provocax , and partially N. vison ,fromother species. Significant differences in size were observed between all species pairs, except C. chinga and N. vison . Phylogeny accounts for a very important part of morphological variance, with cladogenetic events between mustelids and mephitids responsible for almost 55 % of it. The small carnivoran guild of southern South America is represented by species adapted to different feeding strategies, with C. chinga and L. provocax preying mainly on invertebrates, G. cuja and L. patagonicus specifically on small vertebrates, and the non-native N. vison with a highly diverse diet.