On a more serious note (not that I'm not dead serious about wanting both the bat-eared fox and black-backed jackal in particular), just a moment ago I checked what species I've seen at the most facilities that isn't in Planet Zoo. It was exactly what I predicted: the North American river otter. I know it's a completely useless pick for non-Americans, and I imagine that even a lot of Americans would say that the ASCO covers whatever niche they'd use it for, but for me, I think that just goes to show how indispensable it is.
For comparison's sake, here's a chart showing which species (subspecies/breeds largely lumped together, red pandas and African porcupines lumped together) I've seen the most frequently at ~50 facilities. I posted it in the relevant thread on the Animals board yesterday but I'm just so pleased with the visualization that I'm reposting it here. If it were in the game, the NARO would be tied for fifth, at 17 distinct facilities.
And lastly, to bring it all together, what are all of the species I've seen most often that aren't in the game?
17: North American river otter
13: North American black bear
12: common eland, white-tailed deer
10: grey-crowned crane, scarlet ibis
Aside from a few aviary birds (bald eagle, king vulture, blue-and-gold macaw, and laughing kookaburra), that's every single species that hits double digits for me! So in short, these are
objectively the six most important species they could add to the game. Thank you.