Natural history and conservation of the nurse frog of the Serrania del perija Allobates ignotus (Dendrobatoidea: Aromobatidae) in northeastern Colombia

Abstract

We describe new findings on the geographic distribution, habitat uses, relative abundance, tadpoles, and advertisement call of Allobates ignotus. Data of habitat uses and relative abundance were collected during five annual fieldtrips of seven days each one, from April 2010 to June 2014, in a mining zone of Canime Creek Basin, La Jagua de Ibirico, Cesar Department, northeast Colombia. Tadpoles and advertisement call were obtained in La Veguita Creek Basin, Manaure Balcon del Cesar, Cesar. We report six new localities with presence of A. ignotus, all between 7-96 km in straight line to the type locality, from 194-1236 m a.s.l. This species is recorded for the first time in the Tropical Dry Forest Life Zone and in La Guajira Department. Four substrate categories used by A. ignotus were detected (leaf-litter, rocks, naked floor, and lower branches), and differential use was highlighted. The larval morphology of A. ignotus was described, based on 11 specimens between 25-29 stages. Like other Allobates tadpoles, the gap of the second teeth row is "wide". The advertisement call of A. ignotus is composed by a series of high frequency ascending pulsed notes. Possibly, the high frequency of the call is due to the acoustic disturbance generated by the streamflow noise of the creeks. In 2014, a decrease of relative abundance of A. ignotus in Canime Creek was detected. This, coupled to restricted distribution and loss of habitat quality are sufficient criteria to suggest the category of vulnerable for A. ignotus.