Impact of a natural disaster on the habitat and occurrence of Lontra longicaudis (Mustelidae, Carnivora) in Serra da Prata, Paraná, Brazil

Abstract

ABSTRACT Studies about natural disasters impact on fauna are rare in the scientific literature. Concerning Lontra longicaudis (Olfers, 1818), published data could not be found. This study aimed to determine whether the landslides occurred in March 2011 in part of the slopes of Serra da Prata (Parana, Brazil) affected the occurrence of the Neotropical Otter in the impacted area. With this purpose, the study area comprehended an affected river (Rio Santa Cruz - RSC), on the east face of those mountains that was compared to another one, on the same face and with similar original features, but not affected by the natural disaster (Rio das Pombas - RP). The study area is located within the boundaries of a conservation unit (Parque Nacional de Saint-Hilaire/Lange, PNSHL). Seven field campaigns from the altitudinal limit of PNSHL (60 m a.s.l.) towards upstream, were conducted between August 2012 and July 2013. Campaigns consisted of an active search for evidence (scats, footprints, scratches) and otter dens along 3 km of river banks. Other mammal records were also registered. Each evidence was noted down on a field book, photographed and georeferenced. Dens were monitored along field campaigns. Concerning otters, 102 vestiges (11 scratches, 11 footprints and 80 scats) and 17 dens were recorded in the not affected river (RP); and the affected river (RSC) presented only four vestiges (three footprints, one scat) and one den. Other mammal records denoted the presence of eight taxa at RP and 14 at RSC. The conspicuous differences in the amount of evidences of otter presence indicate that the natural disaster affected the otter population in RSC river and that even more than two years later otters had only discreetly come back. On the other hand, other mammal species, such as Cuniculus paca (Linnaeus, 1758) reoccupied the river banks abundantly.