Southern Hills and Basins
In the South Alligator valley there is a juncture of two biogeographical systems: that associated with the Arnhem Land plateau and that associated with the Marrawal plateau (which extends towards Katherine Gorge). The result of this is a large variety of habitats, great species diversity and large numbers of uncommon or endemic species.
Among the animals that are difficult to see are the brightly coloured hooded parrot, the endangered Gouldian finch, the vulnerable red goshawk, and nocturnal animals such as Calaby's mouse and the Kakadu dunnart. Among the animals that are more commonly seen are the black-breasted buzzard (a kite that is easily identified because of the white 'bulls-eyes' in its wings) and the antilopine wallaby (often confused with the red kangaroo).