These lingering calls also help Wolves to define their territory. Neighboring packs chorus back and forth throughtout the night, announcing their presence and proclaiming their land. Human listerners remain profoundly mystified by these ancient cries. Back in 1959, researchers working in Algonquin Park discovered that wolves answer humans when we imitate their howls. Since then, groups of more than a thousand people have been gathering together in Algonquin Park each summer for public wolf howls.
Wolves use a number of different howls.
One of the most often used is a call to reassemble when the pack has become scattered. This howl is a deep, loud, and guttural sound often with a few barks. After a long chase the pack is often widely scattered and needs to reassemble. Wolves don't howl during a hunt. A howl of sheer joy is often heard as a pack gathers or just before the pack sets out on a hunt.