Un inventario de las aves de la región de Inírida, Guainía, Colombia

Abstract

The avifauna of the Colombian side of the Orinoco River is among the least well known of the Orinoquia of Colombia. By contrast, that of the Venezuelan side has received more study, being much more accessible by land and river travel. In distribution maps of Colombian birds, the result has been a large gap (or a question mark) towards the Orinoco for many species, but with records across the river in Venezuela. The region of Inírida is particularly strategic due to its proximity to four important rivers: the Guaviare, Inírida, Atabapo and Orinoco Rivers, which provide a wide variety of habitats, and because it represents a zone of contact between the Amazonian and Guianan avifaunas. Here we present the first detailed inventory of the birds of Inírida of 436 species, including 237 documented by photographs or specimens. These include the first documented records for Colombia of Thripophaga cherriei and Perissocephalus tricolor and a first sight record of Ortalis motmot. Over 100 of the species recorded present significant extensions of their known distributions within Colombia, although nearly all of these had been recorded from adjacent Venezuela. Evidently the Orinoco does not represent a barrier for the majority of species, although a few species are endemic to its banks. Most of the extensions we recorded were of Amazonian species, northwards from Vaupés and extreme southern Guainía or from Guaviare, highlighting the importance of the bands of forest along the Atabapo, Orinoco and Guaviare rivers; ten of these species have yet to be recorded in Venezuela. Many others were eastward extensions from the foothills of the Colombian Eastern Andes, Macarena or Chiribiquete and the eastern Llanos. A recent rapid inventory of the birds of the Estrella Fluvial added ca. 30 species to our list, with several more requiring further documentation, giving a total of ca. 466 species for the Inírida region. Data from several nearby sites could add 30-50 species, hence we conclude that the present regional inventory may be ca. 90% complete. The conservation of this region should be of high priority, especially from the pending threat of large-scale mining. The declaration of the “Estrella Fluvial of Inírida” as an internationally recognized Ramsar site is an important step, but illegal mining already exists on the southern border of this area and effective protection measures are needed.