Abstract

URBINA-CARDONA, JOSÉ NICOLÁS; LONDONO-MURCIA, MARIA CECILIA  and  GARCIA-AVILA, DANIEL GUILLERMO. Spatio-temporal dymanics of snake diversity in four habitats with different degrees of anthropogenic disturbance in the Gorgona Island National Natural Park in the Colombian Pacific. Caldasia [online]. 2008, vol.30, n.2, pp.479-493. ISSN 0366-5232.

Due to cattle ranching and agriculture, natural environments have been transformed into fragmented landscapes. Anthropogenic disturbance affects vegetation structure and microclimate, and changes patterns of snake diversity. This study determines snakes diversity in four habitats that differ in degree of anthropogenic disturbance onGorgona Island, in the Colombian pacific. Visual encounter surveys were conducted during June-July 2001 and February-April 2004 along 31 linear transects, encountering 51 individuals belonging to 13 snake species. We determined inventory completeness to be between 60 and 78%. Highest species richness was found in the secondary forest followed by primary forest and coconut plantations (eight, six and six species, respectively). Highest species complementarity was detected between the prison and coconut plantations, and the prison and primary forest. In conserved habitats (secondary and primary forests) snake diversity doubled, while in the prison and coconut plantations snake abundance increased during the dry season. It is possible that anthropogenic disturbance negatively affects Leptophis ahaetulla, Micrurus dumerili, Oxybelis brevirostris and Tantilla longifrontalis snake species. It is important to invest more effort in snake capture in conserved environments than in disturbed habitats. Data on spatio-temporal dynamics in snake ensembles are essential to correctly focus conservation plans and management of the snake fauna in disturbed environments.

Keywords : Alpha and Beta Diversity; abundance patterns; anthropogenic disturbance; Snakes; seasonal dynamics.

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