July 2009 Volume 20 Two - Indigenous Flora and Fauna Association

Frogs
in Melton
Whistling Treefrog
Melton has an enviable and quite distinct diversity of frogs, despite being in the drier
western region of Melbourne and despite its status as one of the fastest growing
municipalities. Seven species have been recorded in the Melton area so far.
In 2008, after a long dry spring, Melton waterways were
dry; consisting of small isolated waterholes separated
by stretches of dry, parched creek bed. Early December
suddenly brought a weekend of dramatic rains. Creeks
ran high and local wetlands that had been long empty
were filled with water. Waterways that had been silent were
suddenly loud with frog calls. This meant it was a good time
for Melton Environment Group to record frog calls for the
Melbourne Water Frog Census.
Three common frog species, Pobblebonks, Common
Froglets and Spotted Marsh Frogs, were calling loudly in
numerous localities around Melton. The Pobblebonks were
particularly conspicuous, giving their loud territorial “growl”
and grappling aggressively with each other in the submerged
vegetation.
The various frog species can be readily identified by their
distinctive calls, even though the frogs remain unseen. The
loud resonant “bonk” of the Pobblebonk (Limnodynastes
dumerilli), also called Banjo Frog, is the most recognizable.
Almost everyone living in close proximity to a waterway is
familiar with this call, heard mainly during warmer weather.
It also has a distinct territorial “growling” call. The Common
Froglet (Crinia signifera) is by far Melton’s commonest frog.
Its cricket-like “creek creek creek” is heard all year round and
almost anywhere there is water, with vegetation cover. The
“tic” of the Spotted Marsh Frog (Limnodynastes tasmaniensis)
is heard in open, grassy or rocky ponds, often with little or no
vegetation cover. They seem to be the first frogs to colonise
the new man-made wetlands that are often now mandated for
new residential development; and they are often heard where
no other frog species are heard. A significant proportion of
Spotted Marsh Frogs in the Melton area have a rapid fire call,
a series of 4-5 “tics”, as heard in northern and central Victoria,
rather than the single “tic” usually heard in Melton (and in the
rest of southern Victoria). The line of demarcation between
the two populations of marsh frogs may not be as strictly
defined as existing records may suggest.
The soft purring call of the Spadefoot Toad (Neobatrachus
sudelli) can also be heard in Melton South, in chorus with the
more raucous Froglets, Pobblebonks and Marsh Frogs. This
colony of Spadefoot Toads was discovered calling in Rees Road
wetland in Melton South in May 2007. These burrowing frogs
avoid the drought by spending most of their lives beneath
the ground, only emerging to feed and breed when heavy
rain falls. These are only heard at night, and until 2008 they
had only been recorded at a single wetland in Melton South.
These frogs have been recorded by the Melbourne Water Frog
Census in Melton South, Sunbury and Patterson Lakes only.
In 2007, while recording these calls for the census,
environmental science student Richard Akers heard the faint
high pitched whistling calls of Whistling Treefrogs, echoing
across the paddocks in the distance. Driving around muddy
tracks in the dark, following the whistling calls, indicated that
they were calling from somewhere near the adjacent Arnolds
Creek. An unwillingness to venture into muddy paddocks
with a small sedan limited closer investigation.
When heavy rains came again in December 2008 the
area was again visited. It was decided to check a
small dam that was once in the middle of paddocks
INDIGENOTES VOLUME 20 NUMBER 2 9