Notes on the Recurve-billed Bushbird (Thamnophilidae: Clytoctantes alixii) and its connection with a bamboo in a secondary forest in Colombia

Abstract

After going unrecorded for 60 years, a population of the Recurve-billed Bushbird (Clytoctantes alixii) was recently discovered at an elevation of 1650 m in Agua de la Virgen, Ocaña municipality, Norte de Santander, Colombia. Our observations suggest that at this site, this antbird used for its foraging the bamboo Rhipidocladum racemiflorum. The bamboo, called locally “carrizo”, is dominant in the understory of the secondary forests in the region; its soft, hollow stems contain water even during very dry periods. The bird vigorously pecks a hole just above a node of the bamboo stem, then uses its recurved, laterally compressed bill like a can opener to rip open dry, dead bamboo stems by strips, exposing the interior where it searches for arthropods. The notably large hallux and its claw permit the bird to grasp the smooth stem strongly while it is opening the bamboo. We describe the loudsong, alarm and mobbing calls of C. alixii, which suggest that the relationships of this species with putative near relatives may be less close than previously thought. There has been confusion regarding the type locality of C. alixii ever since its description; we suggest that the type specimen could very well have been taken in the vicinity of Ocaña. The bushbird population of Agua de la Virgen appears to be healthy and could be very important for the conservation of this threatened species, justifying the naming of this area as an Important Bird Area (IBA).