POPULATION DENSITY OF Crypturellus noctivagus noctivagus (AVES, TINAMIDAE) IN THE PAMPA BIOME, SOUTHERN BRAZIL

Crypturellus noctivagus noctivagus is a forest bird endemic to Brazil. In the state of Rio Grande do Sul, the species is considered Critically Endangered, and is known for one relictual population in Pampa Biome. In this study, we estimated the population density of this relictual population using the Distance Sampling method. Samplings occurred from September to February, thus comprising three reproductive periods of the species (2012 to 2017). In total, 58 contacts were recorded with C. n. noctivagus individuals in the three reproductive periods. In each reproductive period 81.600 m were covered in trails. We found a density of 0.04 individuals/km², with an average probability of 18 adult individuals. Our results represent the first efforts for density estimation of this relictual population of C. n. noctivagus , which we suggest is composed by the last individuals in the state of Rio Grande do Sul, highlighting the need of local conservation.