Four nests of Black-and-white Owl were observed from 1989-1991 in Tikal National Park, Guatemala; three of the four nests were from a single pair in subsequent years (Gerhardt et al. 1994). Although none fledged young, the study provides the following information about reproduction.
Black-and-white Owl nesting begins in late March and hatching in late April, during the dry season. Nests are located in trees but are not constructed by the owls. Mean tree height was 26.3 ± 7.1 m (range 21-30 m), and mean nest height was 20.5 + 5.8 m (range 16-26 m); all nests were in emergent trees that were among the tallest in the area. Most commonly, eggs are laid on epiphytes, but may also be laid in naturally occurring holes in the tree, or in an abandoned stick nest of a large bird (Gerhardt et al. 1994b, König and Weick 2008). Based on female vocalizations from the nest and the behavior of the radio-tracked male, it appears that the female incubates the egg while the male hunts and finds food. The clutch of four nests in Guatemala was one egg/nest (Gerhardt et al. 1994b) Mean egg mass was 33.8 ± 2.3 g (n = 4); mean length and width were 46.4 ± 1.1 mm and 38.4 ± 1.1 mm, respectively (n = 4) (Gerhardt et al. 1994b).