Cloud-forest Pygmy Owl

The cloud-forest pygmy owl is a small owl, 14.5 –16 cm (5.7–6.3 in) in length with a 92.8–96.3 cm (3.7–3.8 in) wingspan. Weight can range from 75.6 to 79.3 g (2.7 to 2.8 lb). The male and female have similar markings and plumage, but as in many birds of prey this pygmy owl may display sexual dimorphism in size, with the female being more than 3% larger and more than 3% heavier than the male. The standard linear measurements are: the tail measures 46.8 mm (1.8 in) and the bill (from cere to tip) measures 11.3 mm (0.4 in). (Note that all these measurements come from only three males and one female of Glaucidium nubicola.) This presumed sexual dimorphism is referred to as reversed sexual dimorphism (RSD). The cloud-forest pygmy owl has the typical Neotropical pygmy owl appearance. It is dark brown overall, but there are some individuals with a more rufous-brown wash. Its back, scapulars, upperwing-coverts are darker and its rump is washed dark rufous-brown and spotted white. It has whitish spots on primaries and secondaries which form an indistinct band. Its tail is blackish with five incomplete white bands. The chin, sides of throat and upper chest are white, while sides of the chest are rufous-brown. It has inconspicuous white spots on breast and more distinct streaks on lower underparts. Its rounded head lacks ear tufts. The iris is yellow, the legs are yellow too, and the bill is greenish-yellow. It has two nape patches, in the form of two spots of dark feathers edged in white; these resemble eyes and are called “false eyespots”. These "eyespots" are a remarkable plumage pattern found in many Glaucidium owls and some other owl species that are active during the day. The “false eyespots” presumably fool larger predators and perhaps smaller mobbing birds into thinking that the owl is aware of their presence. Its facial ruff, and the facial disk that covers it, are smaller and less well developed than they are in highly nocturnal owl species. Its plumage colours make this species highly cryptic, presumably to allow it to roost undisturbed. It has rounded wings, like other species that hunt from a perch. The cloud-forest pygmy owl is quite similar to temperate forms of Costa Rican pygmy owl (Glaucidium costaricanum), Andean pygmy owl (G. jardinii) and Yungas pygmy owl (G. bolivianum), but it is heavier and has a shorter tail. Besides, it has minimal or complete lack of pale spotting or barring on the back, sides of the chest and flanks. In contrast with the similar appearing Costa Rican pygmy owl, its “false eyespots” are bordered with white in all non-rufous individuals.