The XX Factor

They Eat Wilderness Scouts, Don’t They?

[ Spoilers for Up ahead. ]

Seeking scientific accuracy in Hollywood is a fool’s game. I’ve frothed at the terrible biology of Bee Movie and gnashed at the poor oceanography of Transformers and muttered at the unfortunate physics of Star Wars . So I wasn’t expecting much from Pixar’s latest offering, Up , what with the house floating along on helium balloons. But I was pleasantly surprised. The biology of Up is reasonably accurate-though Kevin the bird might harbor a dark secret.

In Up, our heroes float to Paradise Falls, in South America. This spectacular landscape of flat mesas and giant falls is based off Venezuela’s Canaima National Park , home to Angel Falls, the world’s tallest waterfall. The mesas, called tepui, are ancient rocks inhabited by unique plant communities found nowhere else. Since a barren tepui is a hard place to make a living, many of the plants have turned to meat- they capture insects with sticky bulbs or with water traps. According to Bay Area Science , these excellent plants do get little cameos throughout the movie, but the other inhabitants of Pixar’s Paradise Falls are glimpsed only as skeletons on display.

But what about Kevin? Kevin is a large, colorful ostrich-like bird pursued by the bad guy because she’s a living fossil that will prove that Paradise Falls is indeed a “Lost World.” While there are flightless birds in South America today, they aren’t colorful and they don’t live on the tepui. The most Kevin-like is probably the rhea, a gentle ostrich-like herbivore that grows up to six feet tall and 70 pounds. Rhea roam the low-lying plains of Brazil and Argentina, but are kept as livestock and pets all over the world. Anything that wanders around a Scottish suburb is probably not exotic enough to drive the plot of an entire feature film. That’s why I think Kevin may have been something far more mysterious and dangerous-an ancient terror bird.

The terror birds (also known as phorusrhacids ) were carnivorous flightless birds that ate their way through South America until their extinction 2.5 million years ago. The largest terror bird stood 10 feet tall, weighed 1,000 pounds, and used its giant razor-sharp claws to feed its babies meat, not chocolate. A self-respecting terror bird would have had no fear of talking dogs-it could have could have swallowed them whole and kung-fu-chopped their bones for the marrow. Discovering a living terror bird, though likely fatal, would certainly propel the discoverer to fame and fortune.

If Kevin was a terror bird, why would she spare the lives of Up ‘s heroes? Perhaps her species evolved to vegetarianism over the last 2.5 million years, turning to a life of pacificism and quiet contemplation. Maybe she was saving them in order to eat them later. Or maybe she was entirely satisfied with being fed chocolate. Nonetheless, if I were a Pixar character, I wouldn’t turn my back on Kevin. They don’t award the “fleeing from extinct mega-predator” Wilderness Scout badge posthumously.