First density estimate of the Rufous-fronted Parakeet (Bolborhynchus ferrugineifrons: Psittacidae) in the southern sector of Las Hermosas National Natural Park, Colombia

Abstract

Given the scarce population information available for the Rufous-fronted Parakeet (Bolborhynchus ferrugineifrons), much of which is based on studies conducted more than two decades ago in one locality, I present the first estimate of population density for this species in the southern sector of National Natural Park Las Hermosas - Gloria Valencia de Castaño. Using line-transect distance sampling, I obtained 13 independent detections along seven transects (total survey effort = 300.7 km). Observed data fitted with a uniform key function with cosine adjustments. The estimated density was 4.05 individuals per km² (95% CI 1.68–9.80). Detection probability was 0.42 (95% CI 0.24–0.74) and the effective strip width was 42.17 m (95% CI 24.14 –73.68). Expected cluster size from regression was 7.90 individuals (95% CI 4.74–13.17). These results update our knowledge of the species’ status and provide a quantitative baseline for conservation of this endemic and threatened Andean parakeet.