264 
N.L. McKenzie, L. Fontanini, N.V. Lindus, M.R. Williams 
Table 6 Additional reptiles that might occur inshore 
or on Koolan Island. 
Cheloniidae 
Caretta caretta 
Chelonia depressa 
C. mydas 
Eretmochelys imbricata 
Dermochelyidae 
Dermocltelys coriacea 
Chelidae 
Chelodina rugosa 
Gekkonidae 
Crenodactylus ocellalus 
Diplodactylus conspicillatus 
D. mcmiUani 
D. taeniatus 
D. stenodactylus 
D. ciliaris 
Nephrurus asper 
Rhynchoedura ornata 
Pygopodidae 
Pygopus nigriceps 
Agamidae 
Chlamydosaurus kingii 
Ctenophorus caudicinctus 
Diporiphora magna 
Pogona microlepidota 
Scincidae 
Carlia munda 
C. rufilatus 
Cryptoblepharus 
plagiocephalus 
Ctenotus robustus 
C. yampiensis 
Egernia douglasi 
Lerista praefrontalis 
Morethia ruficauda 
Notoscincus ornatus 
N. wotjulum 
Proablepharus tenuis 
Varanidae 
Varanus scalaris 
V. tristis 
Elapidae 
Demansia psammophis 
Pseudonaja nuchalis 
Rhinoplocephalus 
punctatus 
Vermicellii multifasciata 
Colubridae 
Cerberus rynchops 
Fordonia leucobalia 
Myron richardsoni 
Hydrophidae 
Hydrelaps darwiniensis 
Hydrophis elegans 
(Bathurst), Glaphyromorphus isolepis (Cockatoo) and 
Varanus glebopalma (Bathurst). 
The 10 years of systematic bird records from 
Koolan provide a benchmark for assessing the 
potential bird richness of the many islands that are 
scattered along the Kimberley coastline. One 
hundred and sixteen species were recorded during 
the period, 73 non-passerines and 43 passerines. 
The Welcome Swallow record extends the known 
distribution, and Brush Cuckoo and Barking Owl 
have not previously been recorded on islands in 
the Kimberley (R.E. Johnstone, pers. comm.). 
Absences from the bird list are likely to reflect 
the absence of suitable habitats rather than 
incomplete survey of resident species or regular 
visitors. Koolan is too dry for many Torresian bird 
species. Its annual average rainfall (960 mm) is 
significantly less than many islands of similar size 
further north (South-west Osborne, Katers, D'Arcy 
etc). This is reflected in the minute size and floristic 
paucity of its rainforest patches, which may explain 
the absence or rarity of many "rainforest birds" 
(sensu. Johnstone and Burbidge 1991) on the island. 
Examples include the Torresian Imperial Pigeon, 
Green-winged Pigeon, Orange-footed Scrubfowl, 
Little Shrike-thrush, Rufous Fantail, Rufous Owl, 
Rainbow Pitta, Varied Triller, Green-backed 
Flycatcher and Figbird. Some rainforest birds were 
recorded only in town, probably attracted by the 
high proportion of broad-leafed tropical plants in 
the reticulated gardens of the houses: Yellow 
Oriole and Rose-crowned Fruit-Dove. Low rainfall 
may also explain the absence of massive scree 
species such as Black Grass-Wren and White-lined 
Honeyeater, although White-quilled Rock Pigeons 
occur in similar sandstone habitat on the adjacent 
mainland and on Hidden Island, further south in 
the Buccaneer Archipelago (N.McK., unpubl. data). 
The relatively small areas of mangrove around 
Koolan Island allow an equivalent explanation for 
the rarity or absence of certain mangrove birds that 
are common in larger stands that occur in 
embayments along the mainland coast just a few 
kilometres away: Chestnut Rail, Little Bronze 
Cuckoo, Mangrove Kingfisher and Mangrove 
Robin were not recorded, while the Kimberley 
Flycatcher, Mangrove Golden Whistler, Broad¬ 
billed Flycatcher, Shining Flycatcher and Red¬ 
headed Honeyeater were seen on only a few 
occasions. 
The absence of Golden-headed Cisticola and 
Tawny Grassbirds reflects the rarity of tall 
grasslands normally found on black-soil plains and 
flats around swamps on the adjacent mainland. 
Riparian and fresh-water swamp birds are poorly 
represented on Koolan because there are no 
permanent natural creeks or lakes. Some species 
were seen a few times over the 10 years of 
observation (e.g.. Sacred Ibis, Royal Spoonbill, 
Baillon's Crake and Buff-banded Rail). Others 
typical of these habitats on the adjacent mainland 
were not recorded, including Brolga, White- 
browed Robin, Red-backed Wren, Bar-breasted 
Honeyeater, Yellow-tinted Honeyeater, Black- 
chinned Honeyeater and Chestnut-breasted 
Mannikan. These species will become more 
common if the main ore-extraction pit adjacent to 
the loading jetty becomes a fresh-water lake as 
discussed in Keighery et al. (1995). 
A number of other land birds are known from 
the adjacent mainland or other islands along the 
coast (Smith et al. 1978): Spotted Nightjar, Letter¬ 
winged Kite, Black-breasted Buzzard, Collared 
Sparrowhawk, Grey Shrike-Thrush, Jacky Winter, 
Restless Flycatcher, Black-tailed Treecreeper, 
Singing Bushlark, Fairy Martin, Grey-crowned 
Babbler, Singing Honeyeater, Red-browed 
Pardalote, Zebra Finch, Star Finch, Masked 
Woodswallow, Magpie and Torresian Crow. The 
reason for their absence from the Koolan list is 
unclear. They may eventually be recorded there; a 
third of the birds listed from Koolan were 
encountered three times or less over the 10 year 
period of observation. 
Of the four mammals introduced, only goats 
appear to have survived. The fourteen indigenous 
