Size does not matter: natural history and sexual dimorphism of the striped hog-nosed skunk (Conepatus amazonicus) in Central Brazil

Abstract

Expanding knowledge on natural history of carnivores allows to understand mechanisms species developed for survival and improve decision-making aiming conservation. Studies on eco-morphological aspects of skunks, such Conepatus amazonicus, are scarce and usually based on small sampling size. We assessed roadkill individuals, camera trap records, and biometric data to describe the feeding ecology, activity period, and morphology of striped hog-nosed skunk in agroecosystems and protected areas in Central Brazil. Invertebrates represented critical items in the diet in agroecosystems, and due to an intermediate niche breadth (0.545), skunks could not be classified as specialists or generalists. Males and females have total niche overlap (0.94), and the diversity of items was not affected by proximity to urban centres. Animals develop their activities during the night, with 93% (n = 71) of records from sunset to sunrise. There were significant sex differences in the body masses (\(t\) = − 3.7151; d.f. = 29; P < 0.0001). Males (mean = 2.56 kg) were 30% heavier than females (mean = 1.96 kg), allowing us to infer the existence of sexual dimorphism in C. amazonicus. Foot size and dentition were also larger in males, corroborating the sexual selection hypothesis. Behavioural and morphological adaptations favour predation on insects, prey of low physical resistance, which are also available in agroecosystems. This is the first study to report sexual dimorphism in C. amazonicus. Our results fill a gap in the knowledge of a species that plays a unique role for ecosystem functioning, suggesting that skunks represent the primary medium-sized omnivorous-insectivorous organism occupying the Brazilian Savanna.