Happening to me as well. I haven’t delved too far into the island so I can’t say if its all areas, but its all areas I’ve been too - started in the NE area and travelled maybe half a KM inland (guessing). I’ve tweaked many of the server settings, but I dont have my game loaded currently. I am also running a ton of mods - I’ll copy my mod list below.
In 5-6 hours of play spread out over 4 or 5 restarts in the same area, all I’ve seen is a single crocodile, and some sort of tall, undead-looking humanoid that spawned near some named location, plus the seagulls that fly around by the beach and the fish off the coast.
I started a new game just now with no mods installed and default settings. Nothing spawned in the area I was in (the NE location)… I ran around for awhile, came across a river which had a few crocodiles here and there but nothing else. CAme across an NPC camp that did have NPCs. Eventually started making my way towards the SE spawn area, eventually came across a ruin that had a gargoyle-like thing. Further on, as I got closer to the SE spawn I started coming across the moa-things, deer and wolves. Once I got to th eSE spot I suicided to repawn back at my NE starting spot, and not a single animal was around, still. Went to a spot where I know several of the moa-things hang around and stood there for awhile to see if anything spawned, and nothing at all. So it seems to be a vanilla issue, and not mod related.
mod list, copy-pasted from modlist.txt