Gigantic Owl Species

Scientific name: Ornimegalonyx oteroi Scientific classification: Phylum: Chordata Class: Aves Order: Strigiformes Family: Strigidae

When did it become extinct? It is thought that this giant owl became extinct around 8,000 years ago.

Where did it live? The remains of this bird have only been found in Cuba.

Cuba is a collection of tightly packed islands in the Caribbean Sea. As we have seen, islands are treasure troves of biological diversity as any animal that somehow manages to reach an isolated island can evolve independently of its relatives on the mainland. Long ago, Cuba was home to a unique collection of animals that evolved from North American and South American immigrants. One of the most bizarre Cuban animals was the giant owl.

Giant Hutia

Cuban Giant Owl—The ground-dwelling Cuban giant owl stood about 1 m high, dwarfing most modern owls. (Renata Cunha)

The remains of this bird were first discovered in Cueva de Pio Domingo in western Cuba, and it was thought, initially, that they belonged to a Cuban species of terror bird because of their size. The bones clearly belonged to a large bird that spent most of its time on the ground. In the early 1960s, a paleontologist was examining these bones, and he saw them for what they really were: the remains of a giant, extinct owl. Today around 220 owls species are recognized and zoologists separate them into two groups: the typical owls and the relatively long-legged and highly nocturnal barn owls. For most owls, the day begins when the sun goes down, when they leave their daytime retreats to hunt their prey. There can be few predators as beautifully adapted as the owls. Their senses of sight and hearing are acute, and their wing beat is muffled by the soft bar-bule tips on the leading edge of the flight feathers, which dampen air noise during flight. These adaptations allow them to find prey in low light levels and to make an approach without alerting the hapless victim.

Since the first bones of the giant owl came to light, lots of remains have been found all over Cuba, including three more or less complete skeletons. These bones indicate a large animal that was predominantly a ground dweller. Isolated on the island of Cuba, the giant owl deviated from the owl norm and took up life on the ground. Although there are owls today that spend a lot of time on the ground (e.g., the burrowing owl, Athene cunicularia), they still have large wings and powerful flight muscles and can take to the air with ease. Unlike some other ground-dwelling birds that have completely forsaken the power of flight, the sternum of the giant owl does have a keel, indicating that the living bird's flight muscles may have been large enough to take the bird into the air for very short distances. Much like a turkey, the giant owl was probably capable of short, feeble flights when threatened, but its long legs and large feet suggest that it preferred stalking around at ground level. In terms of size, the giant owl was far in excess of any living owl. The two eagle owl species, (Bubo bubo and Bubo blakis-toni), are the largest living owls and can reach a weight of around 4.5 kg. The Cuban owl was probably double this weight. Because of its size and because Cuba was free of large mammalian predators, the Cuban giant owl may have switched from a nocturnal lifestyle to a diurnal one. Strutting around the forested islands of Cuba, the giant owl used its predatory adaptations to hunt animals as large as hutia (Capromys pilorides), stocky Caribbean rodents and small capybara (Hydrochaeris hydrochaeris), the largest living rodents. Like other ground-dwelling birds, the Cuban giant was probably an accomplished runner, and it very likely ran its quarry down before dispatching it with its powerful talons and beak.

Cuban Giant Owl—The ground-dwelling Cuban giant owl stood about 1 m high, dwarfing most modern owls. (Renata Cunha)

The owls we know today usually build their nests in lofty places that afford the eggs and young some protection from predators. Tree holes and other cavities are favored nesting sites, but these must have been out of the question for the giant owl. Even if it could have reached a tree hole, there were probably few of a sufficient size to accommodate its large body. The only option was a nest on the ground or in a burrow, and fortunately, there were few, if any, Cuban animals to prey on the eggs and young of the giant owl. The presence of two giant birds guarding the nest must have been more than enough to discourage even a hungry opportunist.

Exactly when the ancestors of the giant owl colonized Cuba is a mystery, but the descen-dents of these nocturnal hunters evolved over hundreds of thousands of years to fill the niche of a large, diurnal, ground-dwelling predator. The prehistoric Cuba must have been a paradise, but once again, humans arrived, bringing with them devastation and extinction. The first humans to reach Cuba arrived from South America, Central America, and North America in a complex series of migrations as long as 8,000 years ago. These people, known to anthropologists as the Taino and Ciboney, took up residence and practiced hunter-gathering and agriculture. Ground-dwelling birds that have evolved on isolated islands have absolutely no defense against humans. The giant owl, at around 9 kg, was a considerable source of animal protein and one that was easy to catch. Although the islands of Cuba have quite a large land area, the giant owl, as top predator, could never have existed in huge numbers. Human hunting as well as habitat destruction must have decimated the populations of this bird, and the animals the humans brought with them made short work of the eggs and nestlings of this amazing owl. The youngest remains of the giant owl are around 8,000 years old, and it is very unlikely that a large, cursorial bird could have persisted for anything more than a couple of centuries after humans reached Cuba.

♦ In appearance, the giant owl is thought to have resembled a large burrowing owl (Athene cunicularia), but its remains show that it was actually more closely related to the wood owl (Strix sp.).

♦ A very unusual and extremely rare animal called the "Cuban solenodon" (Solenodon cubanus) still manages to cling to survival on these Caribbean islands, but since its discovery in 1861, only 37 specimens have been caught. This odd, nocturnal, burrowing creature, one of the few venomous mammals, is a reminder of the days when Cuba was populated by odd animals, creatures which evolved in isolation on these tropical Caribbean islands (see the entry for Marcano's solenodon in chapter 3).

Further Reading: Brodkorb, P. "Recently Described Birds and Mammals from Cuban Caves." Journal of Paleontology 35 (1961): 633-35.

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  • carita
    When did Ornimegalonyx oteroi became extinct?
    7 years ago
  • Milford
    4 months ago

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