Presencia de la rata invasora Rattus rattus (Rodentia: Muridae) en el Parque Nacional Sangay, Ecuador

Abstract

Introduction: The black rat Rattus rattus is one of the most invasive and harmful mammals in the world. The species is usually commensal with humans and isdistributed throughout the world except in polar regions. As far as is known, R. rattus has not previously been captured in pristine rainforests in Ecuador. A recentsmall mammal survey in the rainforest of Sangay National Park (SNP) revealed the presence of the species in this important ecosystem, which has been designated a Natural World Heritage Site by UNESCO. Methodology: Sampling was conducted during six expeditions at four sites in SNP (La Libertad, Sardinayacu, Zuñac and Tinguichaca). The trapping effort in La Libertad and Zuñac was three days each, and in Tinguichaca and Sardinayacu six days each, in both the rainy season (February-May) and dry season (July-October). To capture small terrestrial mammals, 100 traps were used at each site (three nights per visit at two sites and six nights in the other two sites), with a total sampling effort of 1,800 traps per night. Results: In April 2012 we captured one male Rattus rattus in Sardinayacu in a trap set 1.5 m above ground level. Discussion and conclusion: It is difficult to accurately determine how the rat moved into this pristine forest, but possibly it traveled along a path used by tourists and rangers that originates in a community 17 Km away which goes through a secondary forest, pasture and then into the SNP to Sardinayacu. It is possible that the invasive rat R. rattus , which is common in disturbed environments, may be moving into pristine environments (Wolf et al, 2005), which would affect native fauna. Key words: Eastern Mountain System, invasive species, Rattus rattus, Sangay National Park, Subtropical rainforest.