You need to differentiate between adults and pups here. An old adult will get as skittish as he11 after a little shooting. A pup, on the other hand, will be back up in 30 seconds or less. That's why they have such a high mortality rate.
I don't believe in calling.
If you try to drive up to a town with your big dually truck with radio blaring, slam all the doors and make lots of noise followed by the muzzle blast of a 17-50BMG, you won't see many PD's. Calls or not.