Bit late to the party but here's a slightly alternative roster for a coastal / islands pack. Going with 7 habitat animals and imagining some N American beach and marina-themed scenery.
Sea Otter
Pack headliner and understandably, favourite coastal mammal for many. They do well in captivity when well cared for and provided with lots of enrichment and moving water. Would really need some unique animations to make them worth having in the game: floating on back, carrying pups, holding hands and tapping shellfish would be ideal and if implemented, could represent PZ's best work.
Hawaiian Monk Seal
A tropical climate seal on the verge of extinction. Very uncommon in captivity but the need to conserve them means that there are some kept at research aquariums, although they are not on display. I'm putting it in the pack because there is an increasing conservation need to protect, breed and rehabilitate them, and because they fit well with the game mechanically.
Black-tailed Deer
The more coastal alternative to the white-tailed, preferring to skirt the edge of forests rather than dense growth. Gives us an American deer with a range along the Pacific line from Alaska to California. Looks similar to the beautiful mule deer with ears almost as large.
Falkland Steamer Duck
Very large, non-flying duck native to...you guessed it, the Falkland islands. It was a toss up between this and the non-flying Galapagos cormorant for me, but this would give us a duck/goose base. Beautiful colouration with some slight variations. Does well in captivity, living up to 20 years.
Grandidier’s Vontsira
Small, rare carnivoran that inhabits a very small coastal range of Madagascar. Looks like a mongoose but is more closely related to the fossa. There are a few species of vontsira, including the very beautiful ringtailed vontsira, but this is the beach-dwelling cousin. Love its floofy tail and I am a sucker for small, unusual carnivorans so here ya go, this is a Villanelle pack after all we gotta have some stripey bandits.
Waigeou Cuscus (Waigeou Island, Indonesia)
The most leftfield choice here and I don't doubt a highly unlikely pick for Frontier. Just here to raise awareness of it really. I love how extraterrestrial it looks, like a gecko-cat wearing prada. From a small Indonsian island. There are possibly none of this especially rare and beautiful subspecies in captivity anywhere, but other cuscus are increasingly being kept and bred for conservation purposes as most are critically endangered. I'd prefer a cuscus to a tree kangaroo personally, I find them very interesting. Has a prehensile tail, eats flowers and would really liven up any nocturnal house.
View attachment 407943
Brown Pelican
My preferred pelican due to its wider Americas range and beautiful plumage. The smallest pelican species, it does well in captivity.
I'm not including a sea turtle, much as I love them. They are very difficult to reproduce and keep happily in captivity. They are best kept as rescues / hatchlings for the purposes of rehabilitation. Most specimens in aquariums are temporary residents who will be released back to the wild. The Hawaiian seal is in pretty much the same boat except that sea turtles migrate...I don't like heavily migratory species in zoos. I do understand why they are on so many people's lists though, they're absolutely beautiful animals and I was lucky enough to swim with one once - probably an Olive Ridley - in the sea off Sri Lanka. Long may they live in the wild.