WEST KIMBERLEY PLACE REPORT - Department of Sustainability ...

considered to provide insights into the evolutionary refuges they occupy, however the
rates of endemism and species richness are not as high as on the Kimberley Plateau
and adjoining islands. One significant patch which may warrant further investigation
into its significance for endemism and species richness is found in the Ningbing
Ranges in the east Kimberley. The Ningbings feature karst landscapes similar to those
associated with the Devonian reefs of the west Kimberley. In another group of
invertebrates, the second highest richness values behind Chillagoe, Queensland, for
the family Pupillidae (minute, air-breathing land snails), was also found, centred on
the Prince Regent 1:100,000 map sheet, and possibly in the rainforest patches of
Prince Frederick Harbour and St Georges Basin.
An estimated 1,500 vine thicket patches occur in the Kimberley (Kenneally and
McKenzie 1991), of which very few have been surveyed to date. It is expected that a
more accurate understanding of greater flora and fauna richness will be revealed over
time as thickets are surveyed in greater detail. High species richness counts for ants
(Andersen 1992b), spiders (Main 1991), scorpions and pseudoscorpions (Andersen
and Burbidge 1991) have been recorded within Kimberley vine thickets. At this time
there is insufficient national data available to determine the true significance of these
groups.
In broad comparative terms, rainforests of much greater age, community complexity
and species richness are found in eastern Australia. However when comparing the
vine thickets of the Kimberley to other hot, dry rainforests across northern Australia,
their importance as areas of invertebrate refugia is readily apparent even when based
on the limited surveying that has taken place to date.
Vine thickets of the northern Kimberley coast and islands and the Kimberley
Plateau, and the Devonian reefs of the west Kimberley, are of outstanding
heritage value to the nation under criterion (a) for their evolutionary refugial
role that has resulted in high invertebrate richness and endemism.
Mangrove refugia: Preferable perches
The west Kimberley has the highest mangrove species richness in Western Australia,
with 16 species in the northwest Kimberley, more than are found in the extensive
mangal communities of Cambridge Gulf and the Ord River (13 species) (Kenneally
1982; Wells 1982). Nationally however, greater species richness can be found in Cape
York (30), and Arnhem Bay in the Northern Territory (20 species) than in the
Kimberley Plateau region, or further south and west at Roebuck Bay (11) (Abrahams
1995, Wells 1982). An ANHAT analysis of the richest mangrove family
Rhizophoraceae also confirmed higher richness and endemism scores in Cape York
(Jardine River and Temple Bay), Cooktown and the Northern Territory (Darwin and
Charlotte Rivers and Melville Island) than for the Kimberley (Mitchell, Lawley and
Roe Rivers and St Georges Basin (Kenneally 1982)).
Mangal communities found between Broome and Napier Broome Bay are an
important part of the Kimberley's refugial story. These communities provide a habitat
for a number of birds that in other parts of Australia are not confined to mangroves,
including species such as the great-billed heron (Ardea sumatrana) and brown-tailed
flycatcher (Microeca tormenti). McKenzie et al. (1991) notes that it is difficult to talk
of the refugial role of mangroves in isolation from rainforest communities. The two
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