There are two widely recognized species of wolves: the red and the gray. However, there is debate over how many species of wolf exist and if there are different subspecies of the gray wolf. Additionally, there is a little-known canid, which lives in the Ethiopian highlands called Canis simensis that is thought to be a very close relative of the wolf.

Wolves are not known for their speed but they can achieve 36-38 miles per hour in short bursts in pursuit of prey.

Wolves are native to North America, Europe and Asia, although they have become extinct in many of their natural habitats because of human encroachment and hunting.

A wolf pup's eyes are blue at birth. Their eyes turn yellow, green, amber, or hazel by the time they are eight months old.

A wolf has two hundred million scent cells inside its nose and can smell 100 times better then a human being. Under favorable conditions, it can smell its prey from about 1.75 miles away.

Biologists have identified a surprisingly wide range of possible functions: Wolves howl to assemble their pack, attract a mate, mark territory, scare off enemies, signal alarm or communicate their position. Sometimes they howl when they wake up in the morning, like humans yawning.

Wolves and ravens have long been connected in folklore and fact. Wherever wolves hunt, ravens are present, scavenging prey. The birds serve as extra eyes and ears, sometimes leading wolves to upwind prey or to carcasses too tough for the ravens' beaks to penetrate.

The Druid Peak wolf pack was released into Yellowstone National Park in 1996 as part of the park's Wolf Restoration Project. The pack would eventually grow to a maximum of thirty-seven members at its peak in 2001 and is believed to be the biggest wolf pack in history.

On the bottom rung of the ladder, you have the omega wolf. As the name implies, the omega wolf is the weakest member of the pack and is often bullied by other members--sometimes to the point of leaving the pack altogether.

The wolf is the largest member of the Canidae family and is further distinguished by a broader snout, shorter ears, and a longer tail.