Oftentimes, these come from the same people who want under-represented clades. They just end up being extra support against their own interest. If you look at the meta-wishlist votes, the example Carnivorans I mentioned out-rank a lot of birds and primates. And yet, there's constant demand for "real" birds. The big question then becomes if people actually want birds. If the people really do want habitat birds, why aren't they dominating the upper whole of the meta-wishlist? Only 2 birds are in the Top 10 and neither are from South America (which is also constantly touted as an under-represented region). So now we have to ask if people actually want more South American birds, or if they're fine with their main goal being diluted by redundant Carnivorans.
Many people want more monkeys and birds, but they also want other things. I can see that monkeys and birds are obvious taxonomic gaps in the vanilla roster. When I try to recreate zoos I've visited, I almost always have issues because there aren't any options for some important niches. I don't consider myself a monkey or a bird person, despite my love for tamarins and raptors.
Like many people, I'm a carnivorans fan. I think big cats, large small cats, hyenas, large canids, bears, and pinnipeds tend to be the 'stars' of zoo sections, and I don't generally like substituting 'big star' animals unless the appearance/foliage tags match almost exactly. On that front, I still need the American black bear for many recreations, and media presence, not zoo presence, would make the walrus an important pick for any coastal pack. Medium-small cats, foxes, small dogs, otters, procyonids, meerkats, skunks, badgers/badger-like, civets, red pandas, martens/ferrets, and mongooses usually seem like filler or fun oddballs to me. I'm a bit more open to substituting some of these, especially those that are uncommon in zoos, but I still think the ocelot, serval, and coati are important/needed for many recreations. They all have decent zoo presence, media presence, and demand. Media presence and demand would also make the sea otter and honey badger pretty good candidates. Beyond those, I would still be willing to pay for several more cats, especially the fishing cat; more oddball small dogs and foxes, especially jackals and raccoon dogs; and some oddballs like martens, a black-footed ferret, civets, and a mongoose. Cute carnivorans can sell packs to a wider audience, and I don't think Frontier would stop working them into packs whatever the wishlist says. I might as well vote on a few favorites.
Pachyderms, giraffes, zebras, kudu, sometimes buffalo, bison, moose, elk, tapirs, and perhaps caprids with climbing rocks are the main ungulates/ungulate-like that I've seen to get the 'big star' treatment while smaller antelope, other deer, pigs/peccaries, camelids, rare equids and farm animals are usually filler or conservation projects. While I still miss kudu, wapiti, bighorn sheep, muskox, and watusi cattle a bit as 'stars,' I am somewhat ok with some of the options for substitutions. For filler ungulates, most want at least two for Asia, especially a deer and the blackbuck. I like muntjacs mostly and would be willing to pay for many species beyond them, but I don't badly need any additional ungulates. I'll still probably keep a few in my wishlist because Frontier is sure to add them anyway.
Red kangaroos and giant anteaters are other mammals that also come close to that zoo niche. Smaller xenarthra, other marsupials, most afrotheria, monotremes, rodents, and lagomorphs are usually seen as filler or neat oddballs. I miss tree kangaroos, tamanduas, arboreal porcupine(s), echidnas, maras, agoutis, and maybe a domestic rabbit, but I think the lineup of oddball mammals is not bad given habitat/hitbox limitations. For reptiles, large crocodilians, Komodo dragons, perhaps green anacondas, and perhaps giant tortoises have star power. Small-medium tortoises, smaller monitors, smaller crocodilians, freshwater turtles, and exhibit animals are usually filler. Chameleons and cobras have star power among exhibit critters; I'm open to a habitat tortoise; and I really want at least one freshwater turtle for ponds even if they don't seem super likely. To build a good Australian zoo, which sounds fun, I'd also want/need an echidna, rock wallaby, perentie, grey kangaroo, possum, and bilby. Besides turtles, I'm mostly ok with habitat reptiles for the moment, but there are so many cool options for small mammals even if I wouldn't call many of them very essential. South America and Australia could definitely use more, though.
For primates, I've seen great apes, baboons/baboon-like, occasionally gibbons, rarely spider monkeys, and golden snub-nosed monkeys (in China) get the 'big star' treatment with larger, dedicated enclosures, good theming, and plenty of space for many guests to spend time viewing them. When spider monkeys and gibbons have large brachiating frames, they can seem like stars, too. I don't personally need geladas or golden snub-nosed monkeys, but they are important to quite a few people and would be very cool. My beloved gibbons and the missing spider monkeys are basic essentials to me, and they also can work as filler. Lemurs and tamarins/marmosets are common, well-loved, and adorable filler animals. We've got a good lineup of lemurs, but I'm still anxiously waiting on tamarins. Capuchins, howler monkeys, sakis, guerezas, guenons, and mangabeys are all generic filler monkeys, which the game is also sadly lacking. I've incorporated several favorites into my wishlist. Given how few we have and seem likely to get, I'm a bit picky about which I'd vote for, but I'm willing to pay for a bunch of them.
Birds generally don't seem like 'big star,' animals to me, but I miss and need them as filler. Penguins, peafowl, flamingos, ratites, eagles, condors, rarely shoebills, and occasionally secretary birds seem like the stars among them. Apart from the flying ones, the rhea, probably one for Africa, and maybe an American flamingo, I think Frontier is mostly done on that end. Waterfowl, pelicans, domestic fowl, wild pheasants, cranes, storks, other wading birds, parrots, kookaburras, hornbills, owls, toucans, and other flying birds usually seem like filler and oddballs. This is where the bird roster suffers. Only a few categories have one member. Granted, ibises, spoonbills, pheasants, and the flying ones are usually kept in aviaries, but I still miss them. Larger, colorful, and talking parrots like macaws, African greys, and cockatoos are a common sight as are smaller ones guests can feed like lorikeets and budgies. Hornbills, toucans, and kookaburras are also common and fun oddballs. Flying birds are heavily demanded on every channel. For habitat birds, ~10 species, including the grey crowned crane, ~3 ducks, and one of the pink trio, would get me to an acceptable place, but there are plenty of other slots on my wishlist for other wants and needs. I badly want flying birds and some basic species, but I don't care as much about the oddballs although I'd still be willing to pay for a few.
