Night
movement in diurnal skinks
488 Park Road, Park Orchards, Victoria, 3114, Australia
Phone: +61 3 98123322 Fax: +61 3 98123355 Mobile: +61 412 777211
E-mail: adder@smuggled.com
Originally published in
hard copy in Victorian Naturalist (February 2009), 126(1):27.
Lampropholis delicata and Saproscincus mustelina
are common small diurnal skinks in urbanised parts of south-east Australia
(Hoser 1989).
Nocturnal
movement in these reptiles is either unknown or never recorded.
At 9 PM on the evening of Thursday 17 April 2003, I drove a car into the single car garage at the residential house address of 105 Jenkins Road, Carlingford, (a Sydney suburb).
To do this, the
roller-door had to be manually opened and then shut again.
Early the
following morning (7 AM) the process was repeated, this time to move the car
out of the garage.
Found resting
were five Saproscincus mustelina and
two Lampropholis delicata. All were positioned directly under the
narrow lip of the door, more-or-less in line and were exposed as the door was
opened.
By virtue of
the absence of the lizards the previous evening, it was inferred that these
skinks had moved into this position during the intervening night hours.
The same night,
there was heavy rain in the area.
It's therefore
believed that the lizards had been literally washed out of their resting areas
and sought refuge in the nearest area not at risk of flooding.
Both species
are common in the area.
Immediately
adjacent to the garage door area is a concrete driveway and concrete paths.
Some distance
from that is gardens and potential night resting spots (cover) for the lizards.
The general
area is well elevated and the garden is sloping with numerous rises and dips
created by rock gardens, pots and the like.
It's therefore
assumed that the lizards didn't just move to higher ground to avoid rising
floodwaters, but instead actually traveled some distance in search of a more
suitable resting spot.
While the above case doesn't show that the two species are usually nocturnal, it does indicate that under exceptional circumstances, including something as frequent as heavy rain, nocturnal activity by diurnal species may occur and depending on climatic extremes may occur more often than the published literature may indicate.
In the 1970's
and 1980's when I kept Lace Monitors (Varanus
varius) and Bluetongues (Tiliqua
spp.) in large outdoor "pits", these reptiles were seen active at
night during and following heavy rain, as they searched for alternative hiding
spots.
At the time,
this activity was thought to be a manifestation of the captive situation.
The case
documented above involving the Saproscincus
mustelina and Lampropholis delicata indicates that my original conclusion may
not have been entirely correct. Put
differently, the same nocturnal activity may also occur in non-captive monitors
and large skinks.
Reference
Hoser, R. T.
1989. Australian Reptiles and Frogs. Pierson and Co. Sydney,
Australia:238 pp.
Non-urgent email inquiries via the Snakebusters bookings page at:
http://www.snakebusters.com.au/sbsboo1.htm
Urgent inquiries phone:
Melbourne, Victoria, Australia:
(03) 9812 3322 or 0412 777 211