Forest Giant Owl

(Caligo eurilochus)




Facts about this animal

The Forest Giant Owl can reach a wingspan of 10-13.5 cm. The upper side of the wings is beige, black – and iridescent blue in males. The underside is finely contrasted with brown, black and creamy white. Most spectacular is a giant eyespot on each hind wing accompanied by some smaller ones. The fine pattern can serve as camouflage if the animal sits quietly on a tree trunk but the large eyespots can frighten a vertebrate enemy if displayed.

Young caterpillars are white with two red longitudinal stripes. Second instar larvae are green, flattened and hairy and have 4 pairs of horns to the rear of the head, 4 spines on the back and two processes to the end of the abdomen. Later instars have 6 spines on the back and are brown.

There are 6 subspecies viz. C. e. caesia, C. e. eurilochus, C. e. galba, C. e. livius, C. e. morpheus and C. e. sulanus.

Adults are crepuscular and often sip on fermented fruits on the ground. Caterpillars feed on leaves of bananas and heliconias and can cause damage in banana plantations. They are nocturnal and rest at the midrib of the leaves during day, sometimes in groups. The older and brown caterpillars rest on the stem where they are difficult to detect.

There are 8 species of wasps and flies known to parasitize on the Forest Giant Owl.

Eggs are laid singly or in small groups to the underside of leaves of the food plant. There are 5 larval instars each taking about a week. The last instar is up to 16 cm long and will moult to a hanging chrysalis. After about 5 weeks the butterfly will emerge. The butterfly can live up to 7 weeks.

Did you know?
that the caterpillars of the Forest Giant Owl can be a pest in banana plantations? that in Papua New Guinea farmers can achieve more income with breeding butterflies for life exhibits in zoos than with cultivation of coffee? They will also support the natural butterfly populations by cultivating food plants.


Name (Scientific) Caligo eurilochus
Name (English) Forest Giant Owl
Name (German) Bananenfalter
Name (Spanish) Mariposa búho
CITES Status Not listed
CMS Status Not listed



Photo Copyright by
Marcel Burkhard



Range The 6 subspecies of the Forest Giant Owl are distributed from Guatemala and Honduras over Venezuela, Guyana, Suriname, French Guyana down to Central Amazon, Peru, Ecuador and Bolivia
Habitat Rainforest and secondary forests
Wild population Unknown but the Forest Giant Owl is not threatened although caterpillars are collected by children and destroyed if they feed on banana leaves.
Zoo population 39 reported to ISIS (2008)

In the Zoo

Forest Giant Owl


Find this animal on ZooLex


Photo Copyright by
Harald Süpfle

Why do zoos keep this animal

The Forest Giant Owl can be used as a display animal because it is not shy and sits fearless on the visitor.


It is also used for education to show the consumption of food by the larva needed for metamorphosis and to illustrate the problems that can arise if economic plants are affected.