Abstract

AVENDANO, Jorge E; CORTES-HERRERA, José O; BRICENO-LARA, Elkin R  and  RINCON-GUARIN, Diego A. Crossing or bypassing the Andes: a commentary on recent range extensions of cis-Andean birds to the West of the Andes of Colombia. Orinoquia [online]. 2013, vol.17, n.2, pp.207-214. ISSN 0121-3709.

Several cis-Andean (i.e. Orinoco-Amazon) bird species have been recently recorded on the west slope of the Cordillera Oriental and the middle Magdalena valley, in Colombia (i.e. trans-Andes). Here, we provide additional records for three of these species. White-tailed Goldenthroat (Polytmus guainumbi), Spectacled Thrush (Turdus nudigenis) and Carib Grackle (Quiscalus lugubris). We report Magpie Tanager (Cissopis leverianus) for the first time in the trans-Andean region. We also discuss some hypotheses explaining these trans-Andean records based on the ecology of these species and landscape characteristics. Given the accelerated rate of habitat loss and fragmentation along the Andean slopes and adjacent lowlands, coupled with the effect of global warming on species' ranges, we suggest that cross- and bypass-Andean expansions could become more common in the next decades. Generalist species could lead those expansions, whereas specialist species could face population reductions due to their limited dispersal abilities. These records show the necessity of monitoring the dynamics between landscape transformation, colonization and population viability of birds, and continuing fieldwork, even in areas considered relatively well sampled in the country.

Keywords : Andean uplift; dispersal; landscape transformation; mountain passes; range extension; trans-Andean.

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