Uso do espaço por Lontra longicaudis (Mustelidae, Carnivora) em ambiente alterado no rio Caí, Rio Grande do Sul, Brasil

Abstract

ABSTRACT. Spatial habitat use by Lontra longicaudis (Mustelidae, Carnivora) in an anthropically modified environment in Caí river, Rio Grande do Sul , Brazil. The use of shelters and space by the Neotropical otter, Lontra longicaudis (Olfers, 1818), was studied in an environment formerly and presently altered by human presence in the Caí river, Triunfo, RS. Most marking sites were used occasionally, while a small percentage was frequently and intensely used. Most sprainting was observed on the soil, and sites were, on average, 1.65m away from the water level. In total, seven shelters were found in the study area and the otter showed preference for specific ones. The most used shelter was a holt built in the riverbank under the roots of a tree. This was the largest shelter and the only one presenting underground galleries. The other shelters were above ground, amongst heaps of branches beneath the vegetation, or under roots and/or fallen tree trunks. The use of space by the otter was correlated to the location of the shelters and to the level of vegetation cover, and seems to be poorly influenced by human disturbance. For the Neotropical otter conservancy we indicate the importance of maintaining the riparian buffers and the protection of the areas with the presence of shelters. KEYWORDS.Neotropical otter, scent marking, shelters, sprainting sites. RESUMO.A utilização de abrigos e do espaço pela lontra neotropical (Lontra longicaudis) (Olfers, 1818), foi estudada em um ambiente alterado e com presença humana no rio Caí, Triunfo, RS. A maioria dos sítios de marcação teve uso ocasional, e uma pequena percentagem teve uso frequente e intenso. A maioria das marcações de cheiro se encontrava no solo a uma média de distância de 1,65m da linha d'água. Ao todo foram encontrados sete abrigos na área de estudo, sendo que a lontra demonstrou preferência por abrigos específicos. O abrigo mais utilizado se constituía em escavações na barranca do rio sob as raízes de uma árvore, sendo este o de maiores dimensões e o único com galerias sob o solo. Os demais abrigos se encontravam no nível do solo e consistiam em emaranhados de galhos sob a vegetação, ou de raízes e/ou troncos caídos. O uso do espaço pela lontra esteve correlacionado à localização de suas tocas, ao grau de cobertura vegetal do local e parece ter sido pouco influenciado pelo distúrbio humano. Para medidas de conservação da lontra neotropical ressalta-se a importância da manutenção da mata ciliar e a proteção das áreas com a presença de abrigos. PALAVRAS-CHAVE.Lontra neotropical, marcação de cheiro, abrigos, sítios de marcação.

Cryptosporidiumspp. andGiardiasp. in Neotropical river otters (Lontra longicaudis) and giant otters (Pteronura brasiliensis) in northern Brazil

“…The neotropical river otter ( Lontra longicaudis ) and the giant otter ( Pteronura brasiliensis ) are two mustelid species that occur in the river systems of the Brazilian Amazon (Carter & Rosas, 1997; Coletti et al , 2013.). The main habitats of these species are rivers, lakes, streams and wetlands, with open margins and vegetation (Coletti et al , 2013; Lima et al , 2013; Palmeirim et al , 2014), with low levels of pollution and human occupation, although they do tolerate environments with anthropogenic factors (Palmeirim et al , 2014).…”

“…Currently, the alteration of habitats caused by human occupation and the exploitation of natural resources in tropical forests constitute threats to these animals (Carter & Rosas, 1997; Coletti et al , 2013); other dangers include boat traffic, pollution and contamination of water resources (Carter & Rosas, 1997). In addition, these species are also threatened by the drainage of wetlands for agricultural practices, mining and fossil fuel extraction (Palmeirim et al , 2014).…”