Something sticks out in Drifter's post that we need to remember. A simple rule of any fishery is that what spawns is what isn't killed before spawning. They spawned because they didn't die.

Wonder why the hatchery runs of salmon seem to have lockjaw in rivers? When only 5-10 % of the adults make it to spawn, the ones that do didn't bite. They didn't arrive in the river and hold for a few weeks, they didn't advertise there presence, and so on.

If we only killed 5-10% of what comes back there are a lot of behaviors that would remain.

The hunters here know this intuitively. If the animal is not hunted hard they behave a whole lot different than ones that are hunted daily.

The fish change, because in ore to survive they have to.