Are all or certain animal populations endangered by the Dragonborn? Can I, by my hunting, drive the whole population of wolves, mammoths, and giants into extinction? Or will the game repopulate the world again? If so, is there a pattern?
I just fast traveled to
to check out whether giants respawn. I killed the giants there on my first trip from Riverwood to Whiterun by abusing the pathing.
The giants were back. They do respawn.
SevenSidedDie points to the answer for animals in his comment: yes, they also respawn.
I also recently revisited
and the dragon there had respawned, so even the static dragons respawn.