Journal of the Royal Society of Western Australia, 87:85-95, 2004 
Reptile assemblage of the Abydos Plain, 
north-eastern Pilbara, Western Australia 
RAHow 1 and J Dell 1 - 2 
1 Western Australian Museum, Locked Bag 49, Welshpool DC WA 6986 
2 Present Address: Department of Environment, PO Box K822, Perth WA 6842. 
(Manuscript received May 2003 ; accepted November 2004) 
Abstract 
A seventy-four day survey extending over three years recorded a diverse herpetofaunal 
assemblage of 72 species. Five frog species were recorded after episodic rainfall events, while 
fifteen snake species and one turtle were infrequently recorded. Data from 51 lizard species showed 
strong habitat preferences. Lizard assemblages on loams associated with creek lines differed from 
those on the sands of the Abydos Plain and those adjacent to rocky substrates. These habitat 
preferences, marked seasonal patterns in activity, and a high proportion of rarely captured species 
indicate that additional species probably remain to be recorded. Fire had a marked effect on the 
abundance and composition of species in Triodia habitats on sandy soils with burrowing and 
fossorial forms surviving best. 
Keywords: herpetofauna, lizards, diversity, variation, habitat preference, fire response 
Introduction 
The diverse herpetofauna of Australia's arid regions 
came to international prominence with the pioneering 
work by Pianka (1969, 1986) and Pianka & Pianka (1976) 
and the comparisons that were made between lizard 
assemblages in desert regions of North America, Africa 
and Australia. Those studies have now been extended for 
over thirty years (Pianka 1996) and have made a major 
contribution to the field of community ecology as well as 
our understanding of lizard assemblages in arid Australia. 
The arid zone of Australia covers over 55% of the 
continent (Williams & Calaby 1985), but studies of arid 
zone reptile species have mainly focussed on populations 
and assemblages in Tnod/a-dominated habitats of central 
Australia (James 1994; Downey & Dickman 1993; Masters 
1996) and the Great Victorian Desert (Pianka 1986, 1996) 
with some studies in more heterogeneous areas of the 
southern arid interior (Read 1995; Smith et al. 1997; 
Thompson et al. 2003a; Cowan &c How 2004). There have 
been no published studies examining the herpetofauna 
of the extensive arid Pilbara region of Western Australia. 
The Pilbara bioregion covers 179 287 km 2 (Thackway 
& Cresswell 1995) and is considered to comprise four 
subregions (McKenzie et al. 2000). One of these, the 
Chichester subregion, consists of Archaean granite and 
basaltic plains covered by shrub steppe of Acacia pyrifolia 
and Triodia pungens with Snappy Gum ( Eucalyptus 
leucophloia) tree steppes on the ranges. This component 
encompasses the Abydos Plain, the major landform on 
Woodstock and Abydos stations of the northeastern 
Pilbara (Tinley 1991a). 
Despite the large area and extensive anthropogenic 
activity in the Pilbara, there have been few attempts to 
document the faunal diversity of the region on a 
systematic basis (Dunlop & Sawle 1980; R.Teale, Biota 
© Royal Society of Western Australia 2004 
Environmental Sciences unpubl; P.K Kendrick, CALM 
Karratha unpubl.) The herpetofauna of the Pilbara is 
known to have high endemism with many species 
confined to small geographic areas within the broader 
limits of the Pilbara bioregion (Storr et al. 1983, 1990, 
1999, 2002). 
As part of a three year survey to document the faunal 
diversity of Woodstock and Abydos stations, data were 
gathered on the composition and structure of numerous 
vertebrate assemblages in the area (How et al. 1991; How 
& Cooper 2002) to provide baseline information on 
species habitat preferences and diversity for future 
management of the area (Berry et al 1991). Woodstock 
and Abydos stations cover an area of over 150 000 ha of 
the north-eastern Pilbara and have been the focus of 
several pioneering biological studies of the arid zone in 
Western Australia including plants (Burbidge 1943, 1945, 
1959), mammals (Ealey 1967a, 1967b, 1967c) and fire 
(Suijendorp 1967). 
In this study, we examine the composition and habitat 
relationships of the reptile assemblages on the extensive 
Abydos Plain over a three-year period and compare this 
information with other studies of reptile assemblages in 
arid Australia. 
Survey Methods 
Woodstock and Abydos stations lie some 150 km 
south of the township of Port Hedland, and the study 
area covers the upper reaches of the Yule and Turner 
Rivers that drain northwesterly across a major 
physiographic unit of the Pilbara, the Abydos Plain. Over 
the three years of this study, rainfall showed appreciable 
seasonal and annual variation (Table 1). Major episodic 
rainfall events in March 1988, during the first survey 
period, and February 1989, after the fourth survey, 
flooded Coorong Creek and all other ephemeral streams 
and drainage lines associated with it. 
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