Altitude as the main driver of the distribution of non-native and native mammals at the Itatiaia National Park

Abstract

Invasive non-native species are considered one of the main causes of biodiversity loss today. Their invasion success in several regions is facilitated by their high dispersion capacity associated with the lack of natural predators in the environment. Protected areas are regions affected by non-native species and most of them in Brazil have documented biological invasions by invasive non-native species. Invasive non-native mammals are an important species group that cause ecological impacts in protected areas, once they can be considered ecosystem engineers. Therefore, it is important to understand and manage biological invasions by non-native mammals in protected areas for biodiversity conservation. Thus, the aim of this study was to test if distance of human settlement, altitude and vegetation characteristics influence richness of native and non-native mammals as well as if non-native mammals negatively influence native mammals at Itatiaia National Park. We installed ten camera traps in the Lower Part and seven in the Upper Part of the Park, distancing 500 m of each other and the first camera trap being at least 150 m of the nearest human settlement. At each sampling point, we collected the environmental variables cited above for posterior analyses. We recorded 20 species of mammals in the Itatiaia National Park, being 17 native and three non-native species. Among these species, seven native and three non-native mammals were recorded in the Upper Part, being the wild boar Sus scrofa and the domestic cattle Bos taurus with higher records among the non-native and the Brazilian common opossum Didelphis aurita and spotted-paca Cuniculus paca among the natives. In the Lower Part, there were 17 recorded native species and none non-native, being white-lipped peccary Tayassu pecari and southeastern squirrel Guerlinguetus ingrami with the higher number of records. Community composition of the Upper and Lower Part of the Park is different; richness of native mammals was higher in the Lower Part whereas richness of non-native mammals was higher in the Upper Part. Richness of native mammals was higher in lower latitudes as well as in forests with lower tree densities and with lower mean tree basal area. Richness of non-native mammals was higher in higher latitudes and in forests with lower tree densities. These results indicate that Itatiaia National Park has a great diversity of species, but also is suffering with the presence of non-native species. Knowing about these species distributions is fundamental to control and manage them. With all this information, we recommend to the Park the management of domestic mammals Canis lupus familiaris e Bos taurus first, followed by the wild boar Sus scrofa.