Use of shelters and marking sites by Lontra longicaudis (Olfers, 1818) in lotic and semilotic environments

Abstract

REIS, N.R. Use of shelters and marking sites by Lontra longicaudis (Olfers, 1818) in lotic and semilotic environments. Biota Neotrop. 12(1): http://www.biotaneotropica.org.br/v12n1/en/ abstract?article+bn02512012012Abstract: The Neotropical otter Lontra longicaudis (Olfers, 1818) (Carnivora: Mustelidae) is a semi-aquatic species spread throughout Central and South America, except Chile. It uses cavities on the river banks or spaces amidst dense vegetation as shelter and defecates in conspicuous places as a means of territorial marking. The study was conducted between April 2008 and March 2009, aiming to compare and correlate the frequency of shelter use and marking by the otters, considering vertical vegetation cover, height, distance, disturbance degree and type of structure/substrate factors, in a lotic environment (Sapé stream, São Paulo state, Brazil) and a semi-lotic environment (Canoas I hydroelectric reservoir, Paranapanema Valley, São Paulo and Paraná states, also in Brazil). The aim was to compare and correlate the frequency of shelter use and marking by the otters, considering factors like vertical vegetation cover, height, distance, degree of disturbance and type of structure/substrate in two areas. It was evidenced that the otter's shelters show visual protection differences in each environment. Around the reservoir, the otters make greater use of areas with higher degrees of disturbance and are selective about the type of shelter structure. Along the stream, the otters favor areas with greater vegetation cover to demarcate. Our results warrant emphasis that other abiotic, biotic or density dependent factors (population number and intra or interspecific competition, for example) may be responsible for the otters' different choice of sites used for shelters and markings in the two environments but they were not identified in this study. Moreover, the different number of samples obtained in each location may have harmed the statistical analyses. However, based on the results, we were able to conclude that the species is able to adapt to the altered environment of the reservoir, using shelters and depositing markings according to the imposed environmental conditions and, whenever possible, it takes advantage of the facilitated food capture offered by environment. Nevertheless, the otters still present some dependence on areas with preserved vegetation, where they find sites with better shelter and marking conditions. Keywords: lotic environment, Neotropical otter, scent marking, semilotic environment, shelter sites. Resumo: A lontra neotropical Lontra longicaudis (Olfers, 1818) (Carnivora: Mustelidae) é uma espécie semiaquática distribuída em toda a América Central e do Sul, exceto no Chile. Utiliza cavidades na margem do rio ou espaços entre a vegetação densa como abrigos e defeca em locais conspícuos como função de marcação territorial. O estudo foi realizado entre Abril de 2008 a Março de 2009 e teve como objetivo comparar e correlacionar a frequência de utilização dos abrigos e sítios de marcações d...

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Site-specific and seasonal variation in habitat use of Eurasian otters (<i>Lutra</i> <i>lutra</i>) in western China: implications for conservation

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Distribution and habitat use intensity of the Neotropical Otter (Lontra longicaudis) in a Colombian hydroelectric dam

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