Distribución potencial y conectividad del paisaje: criterios para reevaluar el grado de amenaza de Campylorhynchus yucatanicus (Aves: Troglodytidae)

Abstract

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 (Yucatán Wren, Troglodytidae) is an endemic bird of the Northern coast of the Yucatán Peninsula, Mexico, with a distribution restricted to a narrow strip of habitat, between Campeche and Yucatán states. Currently, the Yucatán 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 NOM-059-2010. 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 Yucatán 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 Ría Lagartos and Western Celestún 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. Rev. Biol. Trop. 65 (4): 1554-1568. Epub 2017 December 01.

Effects of anthropogenic habitat fragmentation on the genetic connectivity of the threatened endemic Campylorhynchus yucatanicus (Aves, Trogloditydae) in Yucatan Peninsula, Mexico

“…In general, the low genetic diversity of C. yucatanicus (He < 0.50) follows the expected for threatened bird species, with restricted distribution and relatively small populations (Willi et al 2006;Serrano-Rodríguez et al 2017). But our results contrast with those found in C. brunneicapillus populations with a higher level of genetic diversity (He 0.50), which is a least-concern species (Barr et al 2015).…”