Terror Bird

The Terror Bird is a 10-foot tall flight-less killer bird. The Terror Bird was the top predator of South America, For 25 million years, terror birds were untouchable and dominated as South America's top predators. However, 3 million years ago a land bridge formed which allowed big cats like Smilodons and cougars to travel across from North America. Inevitably, some species became extinct when they competed for food and territory or failed to adapt quickly enough. Terror birds had limited success in North America and were displaced as top predators in South America by the invading big cats. Their numbers dwindled until they finally became extinct about 400,000 years ago.

Appearance
Phorusrhacos was a huge, lightly-built bird with a fearsome beak. A recent discovery in North America suggests that they also had claws on their wings, which is unusual, although it is not clear how these would have been used. Terror Birds had grey feathers on their bodies, yellow heads and necks, and a black stripe down the neck and back of the head.

Behaviour
"As they spread down to South America, they were fast taking over from one of the strangest predators the world has ever known,a ten-foot-tall Killer Bird."

- Narration

Phorusracos isn't known as the Terror Bird only because that's much easier to pronounce; this prehistoric bird must have been plenty scary to the small mammals it preyed on, considering its large size, clawed wings, and heavy, crushing beak. Extrapolating from the behavior of a similar (but much smaller) relative, Kelenken, some experts believe the Terror Bird grabbed its quivering lunch with its talons, then bashed it repeatedly on the ground to kill it. Phorusrhacos' beak is a huge hooked weapon like those of modern carnivorous birds leaving us in no doubt as to its diet!

At 10 feet tall, they were far too big and heavy to fly. With long, powerful legs they chased down prey, probably running up to 40 miles per hour, and used their vicious hooked beaks to tear into the flesh of victims. The hips were quite narrow for a bird of its size, and are believed to have given added stability and balance in high-speed pursuits. Stalking prey would also have been a terror bird strategy, creeping out from the long grass in a surprise attack. Although they bore a single claw on one of the fingers, the wings of terror birds were mainly useless. However, they might have been used for flapping displays. A crest of feathers on top of the head was also typical and could have been used for communicating; modern seriema birds repeatedly raise and lower their crests when alarmed.

The bird killed in two ways. First by grasping its prey with its beak and smashing it to the ground repeatedly like its modern relatives, the seriemas. Secondly, and more dramatically, by striking downward with the sharp downward spike at the front of its upper beak. If in the right position, the spike could penetrate the braincase and kill instantly. It had an enormous skull up to sixty centimeters long, armed with a powerful, hook-tipped beak.

In Prehistoric Park
"So it's no use putting in a peice of cuttlefish?" "You'd need a pretty big cuttlefish!"

- Bob and Nigel, about the feeding of the bird.

Nigel Marven remarks that Smilodon were fast taking over from Terror Birds during the Pliocene, and then places down a scale drawing of one, demonstrating the size of the bird: it towers above him, he states it dwarves him.

Meanwhile, the Titanosaurs break their fence and have to be let wander around the park. They go towards the park's main gates, promting Bob Arthur to follow one in a tractor. During this event, Nigel radios him, asking for a bird cage, for a bird standing 10 feet high, but due to tractor engine noise and titanosaur noise, Bob only hears part of the message.

Before Nigel leaves, Bob brings him a normal bird cage, but Nigel tells him not even a Terror Bird egg would fit in a normal bird cage, so Bob decides to build a pen for the next resident.



In Pliocene South America. Nigel sees a female Smilodon stalk a Toxodon and then after a short chase, jump on its head and bite its throat to kill it. More Smilodon come, including some 6 to 8 week old cubs. While waiting Nigel has a coffee and the Smilodon eat their fill and go away. A Phorusrhacos starts to eat from the carcass, and manages to rip off a large peice of meat. Another Smilodon appears and chases it away, forcing it to drop the lump of meat which it had pulled off, and the bird watches the kill from the bushes. Nigel explains that this sort of pressure is what is wiping the Terror Birds out, and this is why he must take one back to Prehistoric Park. Nigel stalks up to that dropped piece of meat and, after the Smilodon charges, picks it up. He ties the meat to the back of his Jeep, and manages to entice the Terror Bird to chase the bait. After near misses, Nigel gets it through the Time Portal, and it screams at Bob as it runs past him. The team traps it in a holding pen, and Nigel and Bob discuss what the Bird needs to eat. Nigel remarks that, in the wild, it was eating huge chunks of flesh, bone and hide. Over the next fortnight, the Terror Bird recovers from its hunger, and becomes a healthy resident of Prehistoric Park.

In the park, the Phorusrhacos has developed a habit of dust bathing near its enclosure's fence, undermining it. Each time, Bob fills the resulting hole with big stones. He realises that this tactic is only "firefighting" and that he will have to make a new fence with the bottom ends of all its posts buried four feet deep. Later, Bob is shoveling up Elasmotherium dung when he sees the Phorusrhacos looking at him from over a fence. He calls on his walkietalkie that the Phorusrhacos has escaped again. A group of keepers come on a van, and manage to tempt the bird back to its pen.

During the Mass Break-Out, its paddock was broken, and it escaped for a short time. The paddock was supposedly rebuilt with fence posts buried four feet deep. It might have stayed inside its enclosure, as it was never actually shown leaving. Although, since it kept escaping with an intact fence, it seems unlikely that it wouldn't escape with no fence at all.

Terror Bird Dunes
The Terror bird Paddock is composed mostly of sandy grassland due to the Phorusrhacos's need to dust bathe.

Trivia

 * Phorusrhacos is not closely related to the giant bird from the Eocene, Gastornis. Actually there is a relative of Phorusrhacos found in the Messel oil shales of Germany, called Aenigmavis. Aenigmavis was found alongside Gastornis, but it is only the size of a chicken!
 * Phorusrhacos is the name for the South American terror bird. When it moved north into North America its fossils are referred to as Titanis. However, it may be that these two animals are the same and will one day both be called Phorusrhacos (which is the older name and therefore takes precedence).
 * Bird fossils are always very rare because they have such lightly built, hollow bones. Despite its size, Phorusrhacos is no exception, and until recently there was very little skeletal material. Recently an underground sinkhole was discovered in Florida containing preserved bones from the North American form.