At least 13 threatened animal species find refuge on Mornington, including the Northern Quoll, Freshwater Crocodile, Red Goshawk, Peregrine Falcon, Grey Falcon, Australian Bustard, Purple-crowned Fairy-wren, and the extraordinarily beautiful Gouldian Finch, one of Australia’s rarest birds. Indeed, Mornington protects one of the largest remnant populations of Gouldian Finches in Australia. The Spectacled Hare-wallaby, Ghost Bat and the Orange Leaf-nosed Bat are also likely to occur here.

Several hundred plant species occur on Mornington, including at least ten rare or threatened species: Acacia gloeotricha, A. manipularis, Echinochloa kimberleyensis, Triumfetta hapala, Eucalyptus ordiana, E. mooreana, Grevillea latifolia, Jacksonia remota, Livistona victoriae, and Olax spartea. Given how few botanical collections have taken place in the Central Kimberley, there are likely to be several plant species on Mornington that are new to science. For example in June 2004 the students of Kimberley TAFE found an undescribed species of Heliotropium.