Thompson & Thompson: Western bearded dragon, an early coloniser of rehabilitated areas 
smaller than that of P. minor. It can therefore be 
concluded that the daily distance moved by P. minor is 
generally greater than that moved for other lizards of a 
similar size. 
The return of P. minor to previously used retreats and 
foraging sites suggests that they have a good spatial 
knowledge of their area, and their movement patterns 
are not random. Some P. minor foraged in confined areas, 
others moved in varying directions across the terrain, 
and others moved in a consistent direction for a number 
of consecutive days. Movement in a consistent direction 
despite walking around obstacles (shrubs, logs, etc) for 
one or more days suggested there was some 'purpose' or 
destination for the direction of movement. This 
'purposeful' movement was not related to capture and 
processing. 
Our intensive pit-trapping program at 11 sites for a 
period of seven days during September and December 
2000; January, April, July, September and December 2001; 
and January 2002 (approximately 45 000 pit-trap days in 
total) only resulted in a single recapture of an adult P. 
minor between field trips, suggesting low site fidelity. 
However, we caught a single female P. minor (#2.6) in 
September within 50 m of where it was caught in the 
previous April, suggesting that this individual had 
remained in the vicinity. It might not have moved if these 
lizards have an activity area in which they forage over an 
extended period, or if it was inactive during the cooler 
winter months. Perhaps P. minor restrict their movements 
to an activity area, and our low recapture rates are due to 
their avoidance of pit-traps, as spooling showed. 
Additional data are necessary to ascertain if P. minor 
confine their movements to an activity area over an 
extended period. 
Studies of the spatial ecology of reptiles often use 
radio-transmitters to locate animals each day. As a 
consequence, linear distance moved rather than the 
actual distance travelled is recorded, as it is not possible 
to determine accurately how far an animal actually 
travelled during the intervening period. Knowledge of 
the ratio of 'foraging distance' to 'linear distance' moved 
for P. minor enables an estimate to be made of daily 
foraging distances from linear displacement data 
collected using radio-transmitters. The ratio of 'foraging 
distance' to 'linear distance' for P. minor was about 1.68:1 
for known distances travelled (excluding days when the 
lizards did not move from their overnight retreat) 
although the range varied markedly as some P. minor 
returned to their point of departure in the morning (ratio 
-> °°), while others moved in almost a straight line for 
most of the day (ratio = 1). 
Pianka (1986) reported that P. minor in the semi-arid, 
red sand-ridge. Great Victoria Desert eats ants, along 
with a wide variety of other invertebrates and plant 
material. One of the P. minor we monitored was 
frequently recorded on ant mounds, presumably feeding 
on ants (although it may have used these mounds as 
perches or basking sites) and another was caught with a 
mouth full of black bull-ants indicating that ants form 
part of the diet of P. minor in the Ora Banda area. 
P. minor as an early coloniser 
The conditions found on rehabilitated waste dumps 
(e.g. steep sides, lack of cover and leaf litter) would be a 
hostile environment for many small reptiles. The 
movement of P. minor from the top of the waste dumps 
and up and down the steep sides, across deep rip lines, 
and into the adjacent undisturbed area indicates that they 
will move across a variety of terrains to forage. This, 
together with their extensive daily movements, their 
willingness to move across unvegetated areas and climb 
steep slopes, and their propensity to forage widely and 
feed in dense low shrubs (Atriplex spp and Maireana spp) 
are likely reasons why it is an early colonising species in 
rehabilitated waste dumps. Interestingly, ants are also 
early colonisers of many rehabilitated mine sites (Majer 
1989) and are a food source for P. minor. 
Reproduction 
Pianka (1986) reported P. minor to have a mean clutch 
size of 7.6 eggs and commit 19.5% of their body mass to a 
clutch. Greer (1989), in summarizing the available 
literature, reported clutch sizes for P. minor from 3-19, 
but mostly 5-8. The higher clutch sizes in Greer's data 
came from Bradshaw (1981) who reported a mean of 8.2 
and a clutch size range of 5-19 eggs. More recently, 
Harlow el al. (2002) reported clutch sizes of 7, 8 and 9 for 
three P. minor, which are similar to the five (7, 7, 8, 9 and 
10) that we recorded. Our measure of relative clutch mass 
(34.4%) is considerably higher than that reported by 
Pianka (1986; 19.5%) but similar to that reported by 
Harlow et al. (2002; 30.0%). We observed that the egg 
mass increases in the few days prior to parturition and 
there was a noticeable reduction in body tissue volume, 
particularly at the base of the tail. We presume that the 
shelled egg mass is increased by the uptake of water just 
prior to laying and this would account for the difference 
between the relative clutch mass values reported for 
oviducal and laid eggs. Given that some P. minor will 
double and triple clutch in a single summer (Bradshaw 
1981; B Jennings, University of Texas at Austin, personal 
communication), these medium-sized lizards make a 
considerable energetic contribution to reproduction. The 
mean egg mass reported by Harlow et al. (2002) was 
smaller (2.02 g) than our eggs, although their neonates 
were generally heavier (mean 1.94 g) and longer (SVL = 
38.3 mm). Harlow et al. (2002) reported the incubation 
period at 29 °C as 60.4 days (58-64), which is similar to 
those we incubated at 27.5 °C, and at 25 °C Harlow et al. 
(2002) reported they took a mean of 105.2 days (range 
100-109) to hatch. 
Field data and captive breeding records indicate the 
first hatchlings for the season appear either late in 
December or in early January. They have a SVL of 35-37 
mm, body mass of 1.3-2.0 g when they hatch, and by 
April have increased their SVL to 65-85 mm with a 
corresponding body mass of 7-11.5g. The presence of 
hatchlings on waste dumps provides additional evidence 
this species can establish itself in rehabilitated areas. 
Acknowledgements: The authors would like to thank Jessica Oates, 
Patrick Cullen, Rebecca Ince, Elizabeth McGuire, Joanna Coleman, Ryan 
Phillips, Chris Clemente and Craig Douglas for the field assistance. All 
lizards were caught under a licence issued by the Department of 
Conservation and Land Management (GGT). Financial support for this 
research was provided by OMG Cawse Nickel Pty Ltd, Placer Dome Asia 
Pacific West Operations, Kalgoorlie, and the School of Natural Sciences 
and the Centre for Ecosystem Management at Edith Cowan University. 
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