THE CONDOTO STUBFOOT TOAD (ATELOPUS SPURRELLI BOULENGER, 1914) AT UTRÍA NATIONAL PARK, COLOMBIA: POPULATION DENSITY MONITORING AND CONSERVATION

Abstract

The population density of Atelopus spurrelli in Utría National Natural Park was assessed in order to establish a baseline to stablish a surveillance and monitoring program for the species, as well as to assess the effect of potential threats on this population. Three streams with previous records of the species were selected in the Natural Park, in which 7 transects of variable length were surveyed. Population density was estimated using the distance sampling method and using the Multinomial-Poisson Mixture model. A total of 191 individuals of A. spurrelli with a density of 0.09 individuals/m² (95% CI: 0.07-0.12) was recorded in Cocalito creek, 0.13 (0.1-0.18) in La Aguada creek and 0.14 (0.10-0.19) in Guachalito. Cocalito creek had the lowest estimated average density, which suggest a differential biophysical or anthropic factor between creeks driving this population parameter. It is suggested to carry out a population monitoring in several periods of the year and multiannual to determine if the density differences between creeks and in comparison to previous studies are artefacts of the methods of analysis, sampling representativity or responses to biophysical and anthropic factors present in a differential form in the creeks sampled.