When all the wolves have been killed, they face each other.
Their first victims are usually those who they have loved, and wolves cannot be killed.
In 1883, up to 1,386 wolves were killed, with many more by poison.
Two years later, 2,600 wolves were killed in response to attacks leaving 624 humans dead.
It is estimated that by the 1870s, 100,000 wolves were killed annually.
The wolf has been killed and you've no more nightmares to fear.
And he said federal agents were aggressive about killing wolves where there are problems.
Until the hunting season began in August, only one wolf was shot and killed - by a camper.
Officially, 1926 was the year that the last wolves were killed within Yellowstone's boundaries.
A wolf who becomes too old to hunt is traditionally driven out or killed by his pack.