The giant owl and those giant claws

When we talk of megafauna we tend to think of the wild and wonderful mammals of the Pleistocene and Pliocene. Megafauna are all the fabulous big and familiar exciting beasts, like mammoths, giant sloths and sabre-tooths, right? Wrong. We don’t automatically think of avian taxa, but we really should as some of them are truly wonderful! Like this chappie here; Ornimegalonyx, the Giant Cuban Owl.

If Hedwig had been an Ornimegalonyx, I suspect Harry would not have had as much grief from Dementors! Standing at over a metre high, with ferocious claws (the Latin name translates as ‘The Bird of the Giant Claws’), this Pleistocene feathered friend was not to be messed with. Ornimegalonyx spp were the biggest owls ever to walk the earth. Remains of these giant flightless birds have been found at rare locations in Cuba. One of these was Sierra de Sumadero, which has since been declared an area of great scientific importance and is now protected, mostly due to the skeletal remains of Ornimegalonyx and other Pleistocene fossils.

That is one big owl. Ornimegalonyx superimposed next to a man and a car. (Image from here -

That is one big owl. Ornimegalonyx superimposed next to a man and a car. (Image from here. Worth clicking the link, to see this guy and this car used as a scale for other giant birds. Wonderful stuff.)

Islands are notorious for evolving odd permutations of species – just think of the tiny pygmy mammoths of Crete, and the cute, but odd, mouse goat, Myotragus. Specimens of Ornimegalonyx were initially mistaken as belonging to Terror Birds (Phorusrhacidae), a previously unknown variety of which had hopped from South America to Cuba. Ornimegalonyx had long legs, similar to Terror Birds, which helped it to run swiftly in pursuit of its prey rather than swooping down like a modern owl. This carnivorous bird was the equivalent of a speedy sight hound like a saluki or a greyhound. Those distinctive long legs gave the species an incredible elegance, although the small to medium sized mammals and lizards it predated on may not have fully appreciated it!

One of the debated arguments is that this bird had a capacity for a very limited flight – the keel, or breast bone, is not like that of the massive and earlier (Miocene) Terror Birds, the Phorusrhacideae. Put your hand flat on your chest over your heart, raise your other hand like you are taking an oath, keep it up, and move your arm towards your back, and then to your chest; the muscle you feel moving is the pectoralis muscle, the same muscle which is massive on birds that fly, so they have pretty big keels. Terror Birds didn’t fly, so their keel was relatively small. The Ornimegalonyx keel was a little larger in proportion leading some to believe it could have possibly flown. The fossil pollen and seeds associated with the bones indicates this big bird liked being among trees; it looks possible that the bird had developed a less than elegant or graceful means of attack – awkwardly fluttering its way into low branches, hunkering down with those big powerful legs then springing up in the air, and landing on ground dwelling animals below. Before you giggle at the idea of leaping leggy flightless owls springing out of trees hooting  ‘surprise!’, consider that it’s likely that  those claws were savage and powerful enough to take down juvenile ground sloths.

The Cuban ground sloth (Image from here)

The Cuban ground sloth Megalocnus rodens  (Image from here)

There’s a possibility this species of giant owl also inhabited other parts of the Gulf Coast, with the discovery at the Kingston Saltpeter Caves of Georgia of avian bones very similar to the Cuban specimens. It’s been presumed these US mainland flightless giants became victims to the overkill hypothesis – like the Cuban birds, their extinction occurs relatively late, some 8 to 10,000 years ago. We know there were humans active within the Gulf area during this period of time. But what of Cuba? As a country which once had incredibly strict censorship laws, most aren’t aware of the islands fabulous past and the sheer wealth of palaeontology and archaeology.

Cuban archaeology is one of the most exciting and mysterious of all the Caribbean. The Guanahatabey and Siboney cultures were just two of the (known) Palaeolithic peoples inhabiting the island just after the end of the Ice Age. This large island is also a perfect place to see environmental determinism in action; it has a clearly defined series of climate and sea-level changes throughout the Pleistocene. Lucky Cuban environmental archaeologists get the ultimate scientific playground of fabulous pollen, spores and artefacts, showing all kinds of changes brought on by everything from hurricanes to tidal floods – a palaeoenvironmental paradise indeed!

The extinction of Ornimegalonyx is possibly synchronous with the hunter gatherer cultures of the Guanahatabey people, who may have arrived between 8000 and 6000 years ago – there’s conflicting evidence, as there usually is within archaeology! As one of those argumentative archaeologists I am always excited and intrigued by human interactions with creatures of the late Pleistocene, and how people reacted to them. Imagine how frightening a walk in the warm Cuban forests would have been if you were a slightly built human of the Caribbean Archaic period, trying to get home to your camp fire, aware that these huge carnivorous birds were sitting in the dusk, shaded by trees… waiting…..always ready to spring out on the unsuspecting, with no differentiation between hominid or herbivore. These owls didn’t give a hoot – they were lethal predators.  If the last of the birds were co-habiting the island with humans, it would make a lot of sense that some of the late extinction could be due to hunting if the Archaic Period’s chronology started around 8000 years ago.  There may be other very likely factors though. Leaving the possibility of anthropogenic land-clearance to one side, there was a complex series of climate changes throughout the Pleistocene, which would have affected vegetation cover, and as a result forced the giant owls into increasingly remote areas, with less chance of successful hunting (a number of almost perfect, intact skeletons of Ornimegalonyx have been found in mountain caves). The remaining, but diminished forests of Cuba were safe again. The reign of the Giant Clawed Bird was over.

Its memory, however, may linger on. In North America there is the legend of the ‘mothman’: an urban legend which involves a terrifying entity which hides in trees, springing out to take down its prey. It is described as having huge eyes and this beasts head can turn almost 360º. Could this be the folk memory of Ornimegalonyx, from Cuban immigrants who moved up into North America, bringing tales of beasts from their homeland with them? Considering the modern Cibrony tribe classify themselves as the direct descendants of the Guanahatabey, it’s just about possible!

Written by Rena Maguire (@JustRena)

Further Reading:

Arredondo, O. (1958), ‘Aves gigantes de nuesto pasado prehistorico’, Divulga cientificas. 10-12. [Full article]

Arrendondo, O.  (1976),  ‘The Great Predatory Birds of the Pleistocene of Cuba’  in Olsonn, L ( ed) Smithsonian Contributions to Paleobiology number 27, Collected Papers in Avian Paleontology Honoring the 90th birthday of Alexander Wetmore Washington DC : Smithsonian Press  169-187. [Full article]

Arrendondo, O. (1982). ‘Les Strigiformes fosiles del pleistocene Cubano’, Paleontologia. 33-52 [Full article]

Badillo, J. (2003), ‘ A General History of the Caribbean’.  New York: UNESCO Publishing. 47-48. [Book]

Cooper, J and Peros, M. (2010), ‘The archaeology of climate change in the Caribbean’, Journal of Archaeological Science. 37. 1225-1232​. [Full article]

Garrido, O. H. and A. Kirkconnell. (2000), ‘Field Guide to the Birds of Cuba’, Ithaca, NY: Comstock Publishing Associates. 253-254. [Book]

Godfrey, L. (2013), ‘American Monsters ; a history of monster lore in America’, New York: Penguin Books. [Book]

Keegan, W. F. (1994), ‘West Indian archaeology: overview and foragers’. Journal of Archaeological Research. 2. (3). 255–284. [Abstract only]

Keegan, W. F. (1989), ‘Creating the Ghuanahatabey (Ciboney): the modern genesis of an extinct culture’, Antiquity 63. 373-379. [Abstract only]

Macphee, R. (1997), ‘Digging Cuba: the lesson of the bones’. Natural History. 106. 50–55. [Abstract only]

Olson, S.L. (1978), ‘A palaeontological perspective of west Indian birds and mammals’ in Gill, F ( ed) Zoogeography in the Caribbean. Philadelphia: Fulton Press. 99-119. [Full article]

Olson, S.L. (1984), ‘A very large enigmatic owl (Aves: Strigidae) from the late Pleistocene at Ladds, Georgia’ Contributions in Quaternary Vertebrate Paleontology: a volume in memorial to John E. Guilday. 1. 44-46. [Full article]

Santos, L. (2010), ‘New early tradition stone tool industries in Cuba’ in Kepecs,S; Curet, A and Corza, G.L (eds)  Beyond the Blockade: New Currents in Cuban Archaeology. Alabama; Alabama University Press. 47-70. [Full chapter]

Saunders, N. (2004), ‘The Peoples of the Caribbean’, Los Angeles: ABC Clio. 82-84. [Book]

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7 Responses to The giant owl and those giant claws

  1. mskvarla36 says:

    Reblogged this on Skvarla Falconry and commented:
    While the giant owl would probably have been unsuitable for falconry, it still would have been amazing to see alive.

  2. Thank you very much for crediting me. You are the first ones to use one of my images (I’m the guy with the car and the cuban gian owl).

    AMAZING Blog.

  3. Hi Roberto! Nice to speak to the guy in the image! We *love* the images with you, the car and the beast! They work so well, and thank you for allowing us to use it!!

    So glad you like the blog! Do get in touch if you want to see a beast on here!! (via @TwilightBeasts on Twitter or via the About Us page!)

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