Abstract

CHACON DE LA CRUZ, José Elías et al. Waterfowl abundance in relation to landscape complexity in a Ramsar site of Northern Mexico. Acta Zool. Mex [online]. 2017, vol.33, n.2, pp.199-210. ISSN 2448-8445.

The response of waterfowl (Anseriformes) populations to the landscape structure was evaluated in a Ramsar site in the state of Durango, Mexico. Water bodies present during the winter were delimited using the calculation of the normalized differential vegetation index (NDVI) in LANDSAT images, covering a period of 35 years (1979 – 2014). The study area was categorized into aquatic and terrestrial environments. Indices of fragmentation were calculated as descriptors of landscape complexity, represented by the abundance and distribution of the water bodies. Waterfowl populational information was obtained from winter counts conducted between 1979 and 2014 by the U.S. Fish and Wildlife Service (USFWS) and by the Mexican Ministry of Environment and Natural Resources (SEMARNAT, by its Spanish acronym). The area occupied by the water bodies presented a marked oscillation of 4,000 to 29,000 ha. The shape, area and isolation of the wetland landscape were the most important factors for the waterfowl. The shape complexity had a positive effect on the presences of birds, while large areas reduced the waterfowl population size. The results suggest that, for anseriformes, this region could be more attractive when water bodies develop complex shapes, the isolation increases and size is reduced. These findings present an opportunity for water management, in order to restore the site and to conserve wildlife species.

Keywords : Ramsar; landscape index; habitat; Santiaguillo; lagoon; landscape; goose; duck.

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