My thoughts of the rankings of Central and South American Animals (not as a local):
I'm going to break this one down by taxa because it's easier for me to think about. Most of the stuff I want is tropical, so by biome wouldn't really make sense here.
Primates:
The
golden lion tamarin is my favorite zoo animal, one of SA's biggest conservation icons, and adorable. Anything less that #1 is not good enough for this cutie. I refuse to vote for any other tamarins (though I like them, too) because I don't want one to challenge its supremacy. That said, the
cotton top and emperor tamarins are underrated. Even if they must end up in a box, I would be so excited to see them in the game. Marmosets are also common in zoos, but they aren't as cute, and they're so small I'm pretty sure they'll need a box. I kind of think the rank of the
black howler monkey and the
Geoffroy's spider monkey should be switched, but they both seem decently appreciated. That particular spider monkey comes in a bunch of color variants, is endangered, and is a common zoo animal. The color variants could potentially be used to pretend they are multiple species of New World Primate, which would be useful given how few there are. I love
squirrel monkeys, and they also have decent support. Personally I would rank the
bald uakari a bit higher despite it being rare in zoos, but I kind of understand if some people are put off by its appearance. They would certainly be a distinct variety pick if the other, much more important species are added.
Sakis, of which the bearded is my favorite, are also underrated given how common they are in zoos.
Night monkeys are an option for a nocturnal primate, and there are a few with some captive presence in the EAZA.
Most Underrated: Tamarins
Birds:
For habitat birds, I'd say the
roseate spoonbill or the
scarlet ibis (my favorite) are the most critical addition. A flash of red/pink would add some color to SA sections and they are unique from the other birds in the game. The scarlet ibis is one of the big 4 birds I'd add to the game (though I'd also be happy with the spoonbill), the others being the mute swan, mandarin duck, and grey crowned crane (though I'd accept a secretary bird). An
American Flamingo would be nice to contrast against the in-game greater flamingo. Rheas are also good for non-tropical rep, and I'd personally prefer the
Darwin's Rhea. The
jabiru is interesting, but I don't think it's common in zoos. The
red legged seriema, trumpeters, and
curassows seem interesting and underrated. If I must pick one underrated habitat bird, I would probably go with the
Muscovy duck. They are unique, common in captivity, and have domestic compatibility.
For flying birds, the popularity of
macaws and
toucans is well justified. The
Andean condor, burrowing owl, and
harpy eagle are both popular and essential as well. For more obscure options, I would probably pick my favorite bird, the
hoatzin. They don't really have a zoo presence anymore, but they are extremely interesting from a visual and taxonomic perspective.
Quetzals, conures, and blue footed boobies also seem interesting and possible, but I'm not sure that they're underrated.
Hummingbirds would be cool if they work.
Most Underrated: Muscovy duck and Hoatzin, Maybe Blue footed booby for the Galapagos?
Carnivorans:
The
South American Coati is extremely popular. I actually wouldn't mind if they added both species. I don't really think it's overrated. The popularity of the
ocelot and
spectacled bear also makes sense. The
bush dog has some fans, and a
SA fox might be good for dog taxa completion, but it's nowhere near as important as the others. I think the
Margay cat is very underrated for an ocelot alternative, especially if they add tamarins. They hunt them, and it would be similar to the fossa. I wouldn't be too upset if we got an ocelot instead. The
pampas cat, Andean cat, and jaguarundi seem possible, but I don't think they are or should be high priority. The most underrated carnivoran is probably the
kinkajou. They are cute, nocturnal, and unlike much else we have. They are a member of the raccoon family, and one I'd heard of as a kid while I somehow didn't know what a coati was until I got here. The
tayra is possible, but I don't really think it's underrated.
Most underrated: Kinkajou and Margay Cat
Ungulates:
The rating of the
collared peccary makes sense. I also think
guanacos and/or vicuñas are underrated. A wild camelid would be a cute addition. Deer are underrated. The
pudu is probably more popular, and I like it as a candidate. My favorite, though not often kept out of its native range, is the marsh deer. It looks like a maned wolf color-wise, and I saw a cute video of a marsh deer playing with a maned wolf.
Marsh deer look different from any deer we have and have aquatic behavior. The
white tailed deer is also an option that would cover NA.
Most Underrated: Deer
Other Habitat Animals:
Maybe I'm one of few that thinks this, but I saw the
tamandua as a critical pick the moment the sloth went into a box. The tamandua would provide an alternate arboreal critter from that family that would work well in an Amazon house. I also agree with others here that
agoutis are deeply underrated, and I would personally go with the red rumped (as long as it's a reddish tropical one, I don't actually care) to get an Amazon agouti. I don't think a second
armadillo is necessary, and they aren't very popular anyway. The popularity of the
Patagonian mara makes sense. I think the
Brazilian porcupine is sort of underrated and should definitely be prioritized over the North American. There are a few other rodents (
paca, pacarana, viscacha, etc.) that are underrated, maybe, but I don't think they're as important as the others mentioned.
Most Underrated: Southern Tamandua and Agoutis
Small Exhibit Animals/Reptiles:
The
Emerald Tree Boa is my favorite, and I'm glad it has such a high ranking.
Eyelash vipers, blue poison frogs, green anaconda, and mata mata turtles are also decently appreciated and cool. The
Argentine tegu is underrated, especially if they could get it to work in a habitat.
Most Underrated: Argentine Tegu (I hope it's a habitat animal, though!)