This IBA consists of a series of contiguous protected areas in the north-west Kimberley. Between them, the Prince Regent River Nature Reserve, Mitchell River National Park, Lawley River National Park, Camp Creek Conservation Park and Laterite Conservation Park are believed to support potentially sustainable populations of all of the key bird species. However, this IBA could be extended to adjacent unsurveyed areas of unallocated Crown Land and Aboriginal Crown Reserve if these were shown to support large populations of the key bird species, particularly the endemic Black Grasswren. This extensive area represents the highest rainfall (>1200 mm) in monsoonal north-west Kimberley and has not been stocked with cattle which damage woodland habitats, especially riverine vegetation and alluvial flats, leading to higher densities of birds such as Partridge Pigeon and White-browed (Buff-sided) Robin. Much of the country comprises rugged King Leopold sandstones. Mitchell Plateau itself is a bauxitic laterite plateau with palm (Livistonia) forests. The high rainfall sustains the richest rainforests on the Kimberley mainland, important for species such as Rainbow Pitta and, on the coast, substantial areas of mangroves, important for species such as Chestnut Rail.
There are historical records of Red Goshawk and Western (Crested) Shrike-tit (Hill 1911). Other notable species recorded by Johnstone and Smith (1981) include Rufous Owl and 14 species of mangrove birds. The endangered Gouldian Finch was relatively common in the IBA in the 1970s but has since disappeared from many former sites (Johnstone and Smith 1981). This species was not recorded in any of 228 Atlas of Australian Birds surveys undertaken in the IBA from 1998 to 2008 (Atlas of Australian Birds database), although it is possible that small numbers may continue to persist. Similarly, the near threatened Australian Bustard was frequent in the 1970s (Storr et al. 1975; Johnstone and Smith 1981) but was not recorded in any of 228 Atlas of Australian Birds surveys from 1998 to 2008 (Atlas of Australian Birds database).
Non-bird biodiversity: This area is one of only two in Australia with an intact mammal fauna. It includes the threatened golden bandicoot Isoodon auratus and Golden-backed Tree-rat Mesembriomys macrurus, and the Kimberley endemics Scaly-tailed Possum Wyulda squamicaudata, Monjon Petrogale burbidgei and Kimberley Rock-rat Zyzomys woodwardi. It has a rich reptile fauna. There are numerous small rainforest patches that protect endemic reptiles such as the rough-scaled python and several species of camaenid land snail.
Pressure/threats to key biodiversity
Management of fire, particularly control of extensive hot fires, is essential. Management of feral animals, especially cats, is essential. Increasing numbers of wild cattle need to be controlled. Mining and industrial development in and close to the IBA needs to be closely regulated in this region of low human impact.
The IBA consists of five conservation reserves. See separate section for details.
BirdLife International (2020) Important Bird Areas factsheet: Prince Regent and Mitchell River. Downloaded from
http://www.birdlife.org on 06/06/2020.