Nesting biology of Nyctiphrynus rosenbergi and Nyctiphrynus ocellatus

The nesting biology for the genus Nyctiphrynus within the family Caprimulgidae is understudied, specifically the choco poorwill (Nyctiphrynus rosenbergi) and ocellated poorwill (Nyctiphrynus ocellatus). We provide the first description of the nesting biology of N. rosenbergi and new information for the nesting biology of N. ocellatus. The nesting location of N. rosenbergi consisted of leaf litter found on the ground. The clutch size of all nests consisted of one immaculate white elliptical egg that measured an average of 26.2 ± 4.1 by 20.9 ± 1.2 mm and weighed an average of 5.7 ± 1.0 g. The incubation period was 26 days (n = 1). On average, the nestling grew 0.9 ± 0.3 mm/day for the tarsus, 2.3 ± 0.4 mm/day for the wing, 0.3 ± 0.3 mm/day for the beak, 0.6 ± 0.5 mm/day for the tail, and 1.7 ± 0.1 g/day for the mass (n = 3 nestlings). We observed biparental care, with females primarily tending the nest during the daytime while males tended at night. The N. ocellatus nesting location was like that of N. rosenbergi. Clutch size ranged from one to two eggs, but the laying of two eggs was observed more frequently (84% of nests). Eggs appeared white, cream, or pale pink in colour, with small brown spots or pink lines, measured an average of 26.5 ± 1.1 by 19.5 ± 1.2 mm and weighed an average of 5.4 ± 0.7 g. The incubation period was 22 days (n = 1). Biparental care was observed, with females primarily caring during the night and males during the day. The longest nestling period was 9 days (N. rosenbergi) and 5 days (N. ocellatus). Understanding the nesting biology of these two species within the genus Nyctiphrynus will fill a gap in our knowledge for the Neotropical portion of the family Caprimulgidae.