I don't envy the individual who would like to sift through Omaha's approximately 1,300 species and attempt to determine what animals fit into this category, although some of the areas of the zoo wouldn't apply here. Beauval likely has a lot of species as well, making this an interesting match, but how many zoos of the world have more than 1,300 species? I'll give an overview on Omaha, as I have tended to do in this ZooChat Cup. **
Omaha has the world's largest Nocturnal House that contains a superb Australian exhibit with vast underwater viewing windows for Johnson's Freshwater Crocodile, Krefft's River Turtle, Pink-bellied Side-necked Turtle, Fly River Turtle and Northern Australian Snake-necked Turtle. There are also Tammar Wallabies, Short-beaked Echidnas, at least 7 or 8 bat species and a wealth of other animals inside the Kingdoms of the Night complex. Someone else can supply a list of 'island' species.
There is the Lied Jungle tropical house and I have no idea how many species would qualify for an 'Islands' category. The same goes for the full-size Aquarium inside the zoo. The Desert Dome has a section called The Red Center of Australia with an astonishing lineup of Aussie reptiles; some of the snake species are found at very few other zoos in North America and there are even exhibits for species such as King Brown Snake, Death Adder and Perentie. There is an Insect House, two Bornean Orangutan exhibits, a Wild Kingdom Pavilion with probably a handful of 'island' species, and here was the list of animals found in Expedition Madagascar in 2018:
Fossa, Aye-aye, Red Ruffed Lemur, Black-and-White Ruffed Lemur, Ring-tailed Lemur, Black Lemur, Mongoose Lemur, Common Brown Lemur, Red-collared Brown Lemur, Crowned lemur, Grey Mouse Lemur, Giant Jumping Rat, Straw-coloured Fruit Bat, Madagascar Ibis, Madagascar Teal, Madagascar Button Quail, Lesser Vasa Parrot, Radiated Tortoise, Flat-tailed Tortoise, Madagascar Big-headed Turtle, Malagasy Hognose Snake, Madagascar Ground Boa, Plated Lizard, Spiny-tailed Iguana, Cheke's Day Gecko, Giant Day Gecko, Oustalet's Chameleon, Panther Chameleon, Powder Blue Reed Frog, Tomato Frog plus various Mantellas and freshwater fish.
** I have visited more than 520 different zoos and aquariums in my lifetime, and 23 out of the 32 finalists for the ZooChat Cup. However, I have focused on Omaha's Henry Doorly Zoo during the final because, by some quirk of fate, many of the zoos that are in the 'Final 8' are ones that I have yet to visit!
Plzen - never visited
Wroclaw - never visited
Chester - never visited
Beauval - never visited
Vienna - never visited
Zurich - was there in 2003
Bronx - was there in 2008
Omaha - was there in 2018, 2012 and 2008