On the Size of the Roc or Rukh

The player characters are currently on an island in Faerie on which a Roc lives. The Roc (in Persian, Rukh) is an enormous bird of prey that appears in the Arabian Nights and probably is based on the legends of Garuda, particularly the story of Garuda carrying away an elephant. So one of the players in the campaign asked, “so how big is the Roc anyways?” That simple question led to about an hour of research, which I’m sharing here so others don’t have to read articles about the morphology of eagle beaks in the Journal of Wildlife Management. If you want more figures on exactly how long things are on eagles, go to that article, Morphometric, Karyotypic, and Laparoscopic Techniques for Determining Sex in Bald Eagles (1985). If you just want the facts, here they are:

These figures are arrived at by assuming that a Roc can carry the largest African Bush Elephants, and that the Roc is built proportional to a Bald Eagle. My Magic rules give the size of a Bald Eagle as 6.3 kg., which is for the largest female, the largest of the species. Eagles weigh 8 to 12 pounds and can carry about three or four pounds, so if an elephant weighs 5,443 kg., then the Roc would need to be 3 times that size, or 16,329 kg., at least, which means the Roc is 2591 times as large as the largest Bald Eagle. We can now calculate the relative size of various Roc body parts by multiplying the size of that part on the largest Bald Eagle by 2591.  Here’s the resulting conversion:

Largest Bald Eagle Roc
Mass (kg.) 6.3 kg. 16,329 kg.
MASS .6 1633
Wingspan 2.3 m. (7.5 ft.) 5.9 km. (3.68 miles)
Beak depth 36 mm. 93 m.
Body length 102 mm. 264 m.
Feathers 7000 7000
Max. size of prey to carry 2.1 kg. 5,443 kg. (M: 544)
Max. size of prey to lift 3.2 kg. 8,165 kg. (M: 816)
Talon length over 76 mm. (over 3 inches) over 197 m. (648 ft.)
Grip strength 2600 pounds per square inch
Normal flying speed 56 kph (35 mph) 56 kph (35 mph)
Max. speed (level flight) 105 kph (65 mph) 105 kph (65 mph)
Max. speed (dive) 241 kph (160 mph) 241 kph (160 mph)
Nest width 3 m. wide, 6 m. high 7.8 km. wide, 15.5 km. high

Based on that, here’s the description for my players trapped on a desert island with this creature:

“The Roc approaches from the sea. Its wingspan is nearly 6 km., its beak is 93 meters long, and its talons are over 197 m. long. It is a ravenous beast and can be seen daily reaping sea serpents and kraken from the sea. Its mountain top nest is almost 8 km. wide, much larger than the mountain top itself and towers over 15 km. into the air, giving the peak an appearance of a very large, craggy mushroom. The nest is constructed of innumerable wrecked ships, a host of palm trees, and cemented together with the bones of sea serpents.”

Now that I’ve answered the question, it seems clear that the Nest itself could be the focus of several weeks of adventures. Ideas for the residents are welcomed. 🙂

By the way, another article on this sort of thing appeared in the Dragon way back in 1978. Look for the article, “How Heavy is My Giant?”

Roc carrying elephant, by Julius Detmold


About lostdelights

An old gamer flying his freak flag, I've been playing table-top role-playing games since 1978. I've been building my own system (Journeyman) since 1981.
This entry was posted in Journeyman, Monsters, Navah, Navah Campaign, Navah Game Summaries, Thoughts. Bookmark the permalink.

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