Owl Butterflies (Caligo memnon) are large, tropical butterflies found in secondary forests and rainforests from Mexico down to the Amazon in South America. Butterflies are typically diurnal (active in the daytime), but Owl Butterflies are crepuscular (most active at twilight), so during the day, you are most likely to see them resting. I observed this somewhat battered Owl Butterfly perched on a leaf on a dark, misty May day in Alajuela, Costa Rica.

Owl Butterflies have an up to 6 inch (15 cm) wingspan. Their dorsal wing surfaces (seen when they are in flight) are broadly edged with dark brown gradating to tan on the forewings and dusky blue on the hindwings. Their ventral wing surfaces (seen when they are resting) are a cryptic, mottled brown with cream at the base of the forewings and a large eyespot on the hindwings. This butterfly's tree bark-like patterns, which are also shared by many owls, help to camouflage it from predators like birds, and its staring, owl-like hindwing "eyes" can help deter any predators that do spot it.

Like a number of other tropical butterfly species, adult Owl Butterflies feed on the oozing juice of rotting fruit. Their caterpillars feed on heliconias (Heliconia spp.), cannas (Canna spp.), and especially bananas (Musa spp.).