Habitat use, density, and conservation status of the white-browed guan (Penelope jacucaca Spix, 1825)

Abstract

The white-browed guan (Cracidae: Penelope jacucaca) is an endemic bird species to the Caatinga, the largest centre of dry forest in South America. This taxon was considered Vulnerable by the International Union for Conservation of Nature (IUCN) due to continued habitat loss within its distribution and intense hunting pressure that contributed to population declines. However, information on population aspects and habitat use by P. jacucaca, which is fundamental for monitoring its conservation status, is not available. We studied habitat use (analysed in a Generalized Linear Model) and population density (estimated by distance sampling) in a specific area in Northeast Brazil. Using species distribution modelling (SDM), forest cover loss data (performed in the MaxEnt program) and quantitative information about hunting, more rigorous estimates of the distribution limits, available habitat, and population declines of P. jacucaca were generated. Based on the IUCN criteria, we applied analysed data to reassess the conservation status of the white-browed guan. Local density was estimated at 13.1 individuals/km2 and the estimated number of individuals removed per year due to hunting was 121.7 in the forest cover area (110.46 km2) of the Serra de Santa Catarina. Consequently, the annual removal rate of hunted individuals in the study area corresponds to approximately 11% of the population. The habitat use analysis pointed to a strong positive association with seasonally dry deciduous forest (SDDF) vegetation and with arboreal vegetation. The SDM indicated a potential distribution (climatically favourable) area of 675,823 km2, and forest cover and loss calculations indicated a total of 81,307 km2 of available suitable habitat in 2013. Therefore, comparing these results to the IUCN criteria, we recommend that P. jacucaca remain in the Vulnerable category.