Activity patterns and ecological relations of the Nocturnal Curassow in the northern Ecuadorian Amazon

Abstract

The Nocturnal Curassow, Nothocrax urumutum, is one of the most elusive land bird species in the mainland and foothills of the Amazon. In order to evaluate the pattern of activity of the Nocturnal Curassow and compare it with 3 species of competitors and 3 species of predators, we carried out surveys in three locations in the western Ecuadorian Amazon. Between July and October 2015 to 2017, 90 camera traps located at random 1 km from each other, in an area of 90 km2 were used. We generated activity patterns by means of Kernel density curves and we estimated the overlap coefficient between competitors and predators of the Nocturnal Curassow. One-hundred percent of the records were daytime, with peaks of activity between 06:30-08:30 and 14:00-18:00 h. Four species presented overlapping coefficients with the Nocturnal Curassow > 60%, while 2 species did not exceed 44%. The pattern of activity of the Nocturnal Curassow was significantly different with respect to the gray-winged trumpeter, red brocket, ocelot and tayra, and it did not change with the presence of black aguti and domestic dog. Our results support the observations of bimodal, solitary or pair behavior and the temporary partitioning of the Nocturnal Curassow, as mechanisms to decrease or avoid encounters with competitors and predators.