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Captive wolves howl differently

22 August 2013 Last updated at 16:59 BST

Wolves howl more when a close companion or dominant group member leaves.

That's what scientists found when they analysed how captive wolves reacted when one of the pack was taken to the forest for a walk.

The remaining wolves do not howl because they are in distress, the researchers say.

Rather, wolves could be using the howl in a strategic way to regain contact with dominant individuals or with friends.

Read the full story: Howling wolves gives clue to top dog