I have been hunting rockchucks for over 20 years and have seen some crazy things about their reproduction. Generally speaking, I put off hunting them until the little ones are able to survive by themselves.
My experiences tell me that there is a pattern of never seeing the very large, old chucks. I have observed them for years from distances and see what happens when the old chucks hear or see a vehicle. They head for the den and don't poke their head out for extended periods of time. I have been able to shoot two very large chucks, one sitting on a rock sunning himself at 100 yards. The other poked its head out of a den and I shot it from 200 yards.
The latter chuck was 28" from nose to base of the tail. I figured it weighed over 25 lbs. I was recently in central Oregon and the land owner told me he killed a big one years ago that he weighed. Said it went 32 lbs. That is a huge chuck and he had no reason to stretch the truth.
Another observation, is if one wants the chucks to abandon a den, is to cripple a chuck and let it go underground and die. In those situations where I have had that happen, the next season there would not be any chucks or sign of them at that den.
On the two pieces of ground we hunt in central Oregon, we have shot over 60 chucks each of the last three years. It seems to not matter how many we shoot, they continue to produce more young. In the piece of ground I shoot in s. Oregon, we have shot between 56-66 chucks each year for many years. Yet the populations tend to be about the same each year.
So, it makes my case that the survivors are those older chucks that no one sees very often. I would also have to figure they are the producers of the young chucks that show each year. I realize that there are some 2-3 year old chucks that survive, but mainly the old one sustain the populations.
I would be interested in others experiences regarding chucks. By the way, I called the rancher in S. Oregon and he said they have a bumper crop of chucks this year. He also stated that after we left last year after killing 66, he saw very few until spring.
