Records of the Western Australian Museum 17: 249-266 (1995). 
Biological inventory of Koolan Island, Western Australia 
2. Zoological notes 
N.L. McKenzie 1 , L. Fontanini 2 , N.V. Lindus 2 and M.R. Williams 1 
1 Department of Conservation and Land Management, PO Box 51, Wanneroo, Western Australia 6065 
2 RMB 312 Manjimup, Western Australia 6258 
Abstract - In terms of its biota, Koolan is the most thoroughly inventoried 
island on the Kimberley coast. We provide annotated lists of the animal 
species known from the island: three earthworms, eight land snails, two 
scorpions, one centipede, nine spiders, two ants, 34 butterflies, one 
amphibian, 35 reptiles, 116 birds and 18 mammals. In addition, the W.A. 
Museum holds unsorted collections of moths and beetles. A range of animals 
have been introduced, including an earthworm Dichogasler bolaui, a land 
snail Laevicaulis alle, an ant (Monomorium destructor), a cockroach and four 
mammals including the feral goat ( Capra hircus). Koolan's indigenous fauna 
is a sub-set of taxa known from the adjacent mainland, although the blind 
snake Ramphotyphlops yampiensis, and the land snails Kimboraga koolanensis 
and Amplirhagada astuta, appear to be endemic to the island. The bird list 
was accumulated during 10 years of monthly observations, but data on other 
components of the island's fauna are uneven because of sampling artefacts, 
with a bias towards large land snails, large butterflies and snakes. 
Nevertheless, the richness of these groups indicates that the numerous 
rugged sandstone islands along this tropical sub-humid coastline support 
complex faunas. 
INTRODUCTION 
Koolan is the only Kimberley island with a long 
history of invertebrate and vertebrate collection. 
While the earliest record we can find is of the land 
snail Kimboraga koolanensis described by Iredale 
(1939), most collections have been made since 1965. 
Broken Hill Pty Ltd developed an iron ore mine 
on the island during the 1960's. By 1985 there were 
150 houses and nearly 900 residents, and a range of 
exotic plants and animals had been introduced. 
Fortunately, domestic cats and un-sterilised female 
dogs were forbidden. 
The geology of Koolan is described in Tyler and 
Griffin (1993). The island has an area of 2580 
hectares. Its Proterozoic sandstone lithology is 
expressed as rugged slopes, ridges and uplands 
mantled with rock scree and shallow skeletal soils 
that support savanna woodland communities of 
eucalypts over hummock grass. The coast is steep 
with narrow gullies and frequent embayments, but 
few beaches. 
Koolan has a tropical sub-humid climate. It 
receives an average of about 960 mm of rainfall 
annually. The "Wet" usually extends from 
December to April, although most rain falls in 
January, February and March. Virtually no rain 
falls from May to November. 
Data on of the island's indigenous animals were 
accumulated gradually by island residents and 
occasional visitors. This opportunistic pattern of 
sampling has left gaps in our knowledge of the 
island's vertebrates and macro-invertebrates, 
particularly among the relatively immobile taxa 
likely to be most affected by introduced species. 
The only systematic biological surveys were 
monthly bird observations made by one of the 
authors (L.F.) over the period 1983 to 1993. 
From 9 to 15 February 1993, two botanists and 
one zoologist from CALM collected plants, 
earthworms, land snails, reptiles and bats to reduce 
this sampling bias. The field work was carried out 
just a few months after the mine closed to provide 
a basis for monitoring the persistence of indigenous 
and introduced species; the town and mine 
infrastructure were being dismantled at the time. 
This paper reviews the zoological data available 
from Koolan. Keighery et al. (1995) present the 
corresponding botanical data. 
METHODS 
The majority of the zoological voucher specimens 
from Koolan were collected opportunistically by 
BHP employees resident on the island. Most are 
lodged at the Western Australian Museum, but 
some Koolan land snail specimens are held by the 
American Museum and the Chicago Field Museum 
of Natural History (Solem 1985). 
A search of the invertebrate registers at the W.A. 
Museum revealed that L. Vernon (= L.F.), O. 
