Potential distribution and landscape connectivity: criteria for reevaluating the threat degree of Campylorhynchus yucatanicus (Aves: Troglodytidae)

Geographic distribution and habitat quality are key criteria for assessing the degree of risk of species extinction threat. Campylorhynchus yucatanicus (Yucatan Wren, Troglodytidae) is an endemic bird of the Northern coast of the Yucatan Peninsula, Mexico, with a distribution restricted to a narrow strip of habitat, between Campeche and Yucatan states. Currently, the Yucatan coast has lost more than half of the coastal dune vegetation, and other habitats have been modified mainly because there is no urban development plan and the natural resources management is poor. These factors threaten C. yucatanicus, which is listed as a near threatened species by IUCN and as an endangered species by Mexican law NOM059-2010. In this paper, C. yucatanicus's potential distribution was modeled using 64 presence records from several sources (1960 y 2009), a set of climate variables, and a vegetation index layer of normalized difference (NDVI). To assess the degree of landscape connectivity we used a map of vegetation types and land use, distance to villages and paved roads. The potential distribution model showed an area of approximately 2 711 km(2), which is 2 % of the total area of the Yucatan Peninsula distribution. In this area, only 27 % is protected by Biosphere Reserve category and only 10 % belong to core conservation areas, with land use restrictions and relatively effective protection. The populations from Ria Lagartos and Western Celestun regions appear to be the most isolated following the model of landscape connectivity. Landscape permeability among fragments of dune vegetation near the coast is low, mainly due to the distribution of urban areas. These results can be used to establish management strategies, and show that the species is in more delicate conditions than what it has been described by IUCN. We consider that C. yucatanicus should be given endangered category by IUCN, because of their distribution and the context of the current landscape connectivity.