Meet the Atreus Owl butterfly (Caligo atreus), also known as the Magnificent Owl or the Yellow-edged Giant Owl. The large spots on the underside of its wings bear a striking resemblance to an owl’s eyes—a deceptive defense mechanism that gives the species its evocative name.

With a wingspan ranging between 5.5 and 6.3 inches (140–160 mm), this is one of the largest butterflies in existence. Alas, its massive size makes it relatively slow-moving and vulnerable to avian predators, so the Atreus Owl has adopted a crepuscular lifestyle. It is most active in the dim light of dusk and dawn, making daytime encounters particularly rare.

While traipsing through the Costa Rican jungle at night, finding such an intriguing subject resting on a vibrant green leaf was a moment of pure magnificence—a glimpse into the hidden, yet highly active, nocturnal life of the rainforest.