One thing I noticed in the picture of the pack- look how many black ones there are. This is not normal, either.
Here's an example of a big bad black wolf made good. Not quite your typical brush wolf, red wolf or painted malamute.
They can be called in with a coyote call as well. Locating howler's etc. Woves do not allow coyotes. If a coyote comes in to the call, there are quite likley, no wolves around.