devtrackers.gg
It was a bit bare before
I think all the joke answers have been made. I'm pretty sure the real answer was due to the Player Owned farm. All those bears were in the area, and instead of just deleting them they just moved their spawn and wander area.
It's because the pen perks extend slightly outside of the POF map squares, and the bears have benefitted from the Like Rabbits perk.
(I think I did this during POF, just moved the spawns over a bit. Seeing this thread pop up from time to takes make me happy; so much better than seeing a bunch of "Who removed all the bears?" threads.)