Species richness and relative abundance of the native mammalian fauna in a relict of the Espinal ecorregion in the south of Santa Fe province (Argentina)

Abstract

Here we present species richness and relative abundance of mammals in a relict of a xerophilous forest from the middle basin of the Carcarañá river (32 ° 582 S – 61 ° 152 O), Santa Fe province, Argentina. Native vegetation, belonging to the phytogeographic province of Espinal , is characterized by noticeable variations in relatively reduced areas, contrary to what is observed in surrounding areas. The methodology used consisted in following lineal transects in search of activity signs (faeces, animal tracks and other traces), direct observations, interviews with locals, and photographic traps. The obtained information was used to calculate the relative species abundance index (S). Eight species were recorded, belonging to eight families and four orders, indirect observations being the most effective method. According to the relative abundance of the recorded species, the Pampas fox (Pseudalopex gymnocercus) had the highest occurrence value (0.48 ind/km), whereas the lowest occurrence values were given by two other species: the skunk (Conepatus chinga) and the capybara (Hydrochoerus hydrochaeris) with an abundance index of 0.07 ind/km each. In addition, we provide information on the species Didelphis albiventris, Myocastor coypus, Chaetophractus villosus, Leopardus geoffroyi and Galictis cuja.