250 
N.L. McKenzie, L. Fontanini, N.V. Lindus, M.R. Williams 
Figure 1 Eastern end of Koolan Island, showing 
principal 1993 collecting sites. 
Milton, F.C. van Ingen and W.H. Butler collected a 
range of arachnid, myriapod and insect specimens 
from Koolan between 1965 and 1990. The bulk of 
these invertebrate collections remain to be 
identified; only the butterflies and the registered 
specimens of arachnids and myriapods are listed 
herein. Butterfly nomenclature follows Common 
and Waterhouse (1981). The butterflies were 
identified by M.R. Williams; we have incorporated 
the records listed by Koch and van Ingen (1969) 
and Koch (1975) although the relevant specimens 
have neither museum registration numbers nor 
field collection numbers. 
The February 1993 field work was carried out at 
the height of the "Wet", when most tropical plants 
flower and set seed (Wheeler et al. 1992). This is 
also the best time to collect the region’s indigenous 
earthworms. Kimberley earthworms aestivate deep 
in the soil profile during the six- to eight-month 
dry season; they are active near the surface only 
during the "wet” (McKenzie and Dyne 1991). There 
were heavy rains during the fieldwork in February 
1993; soil profiles on Koolan were damp to moist. 
A total of 28 earthworm quadrats (cf McKenzie 
and Dyne 1981) were sampled in the range of 
habitats on the eastern part of the Island: savanna 
woodlands, rainforest patches (semi-deciduous 
vine thickets), house gardens, and along a creek on 
the north side of town. Additional grab samples of 
earthworms were taken in town to increase the 
number of taxonomic vouchers. The earthworms 
were identified by Geoff Dyne (Department of the 
Environment, Sport and Tourism, Canberra). Land 
snails were sought opportunistically in two vine 
thickets and in town; earlier records were gleaned 
from taxonomic literature. The land snails were 
identified by Vince Kessner (Adelaide River, 
Northern Territory). 
The W.A. Museum holds reptile and mammal 
specimens collected by island residents such as N. 
Lindus (from 1981 to 1993), L. Vernon (= L.F., 1983 
- 1993), G. A. Robinson (1961), O. Milton (1965 - 
7), F.C. van Ingen (1965 - 74). Specimens were also 
contributed by visitors such as W.H. Butler (June 
1965 and November 1973), B. Maryan and D. 
Robinson (August 1992) and other biologists 
during brief visits. During our February 1993 field 
work on Koolan, we used mist nets and ultra¬ 
sound recorders to survey bats that were foraging 
in the savanna woodlands, mangroves and town. 
Bats were also sought in their day-roosts in caves 
and buildings. We set traps for non-volant 
mammals in the savanna woodlands and along the 
edge of the mangroves and foot of the scree slope 
near site V2 (Figure 1), and made nighttime 
spotlighting traverses along the island's road 
network. In contrast, our approach to sampling 
amphibians and reptiles was entirely opportunistic. 
Reptile taxonomic names follow Ehmann (1992); 
Numbers prefixed with "R" or "M" in the 
vertebrate species lists refer to specimen 
registration numbers at the W.A. Museum. Other 
specimen numbers in brackets relate to data from 
animals captured during the 1993 survey, but 
subsequently released. 
One of the authors, Lee Fontanini (= L.F.) lived 
on Koolan Island from 1983 to 1993. The bird list 
herein summarises her 10 years of monthly 
observations in terms of species' seasonal presence, 
abundance and habitat-use. Nomenclature follows 
the Blakers et al. (1984). Mangroves around Koolan 
are either narrow fringes or difficult to reach, so 
her visits were infrequent (once or twice per year) 
and restricted to the stands in "Barramundi Bay", 
south of town. These are by far the largest stands 
on the island. 
Latitude and longitude coordinates cited in the 
text were measured from the "Yampi" 1 100 000 
series topographic map. 
RESULTS 
Earthworms 
We recorded two indigenous species belonging 
to the genus Diplotrema, and an introduced species 
Dichogaster bolaui (Michaelsen) that was only found 
in town gardens. In contrast, Diplotrema were 
common in the vine thickets, scarce in the savanna 
woodlands, and were not found in the townsite. 
To confirm the scarcity of earthworms in the 
