Melton has an enviable and quite distinct diversity of frogs, despite its 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 & 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 & 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 & central Victoria, rather than the single "tic" usually heard in Melton (& 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 & 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 only a few years ago but is now close beside a rapidly growing residential neighbourhood. This small insignificant looking wetland was formed by the damming of a deep gully, creating a narrow deep dam. Intermittent flows in Botanica Springs Creek after rain cause the water level to fluctuate wildly. Some sedges and numerous weeds grow around the edges and rocky shelves, strewn with builders' rubbish. The previous week the dam was half empty, the waterline surrounded by bare rocky banks.  After heavy rain the previously high and dry grass was now submerged and water was running over the bank. There was also a deafening chorus of frog calls. Numerous Pobblebonks were hopping about on the wet ground.

The calls of the usual Pobblebonks, Spotted Marsh Frogs & Common Froglets were almost drowned out by the piercing birdlike calls of Whistling Treefrogs (Litoria verreauxi). Although these frogs are quite small, (2-4cm) their calls are surprisingly loud, and can be heard over a kilometer way. At close range this can be deafening. After a while as the night grew darker, the soft purring of Spadefoot Toads could also be heard. Five frog species made this a record for Melton. A visit the following evening brought a greater surprise. As we approached the dam Richard remarked that he could hear a Growling Grass Frog (Litoria raniformis). The narrow dam with its lack of aquatic vegetation looked the most unlikely place to find one of these threatened frogs. However the loud growling call coming from the water's edge was unmistakable. It continued to call loudly as the digital recorder was placed close by. Despite the loudness of its call the frog itself remained unseen among the submerged grasses. The following night he recorded three Growling Grass Frogs. This made a total of six frog species from a single small wetland, (Treefrog Hollow?) and an unlikely looking one at that. Faint treefrog calls were also heard from two other similar dams across the paddocks, indicating future frog census activity after the next heavy rains.

Several hundred metres upstream at the beginning of 2008 a manmade wetland was created as part of a new residential development. This wetland, Botanica Springs, was extensively planted with indigenous plants. A year later the wetland is now densely fringed with several species of rushes, and edged with large tussocks of Poa grass and Lomandra, interspersed with small teatrees, bottlebrushes and Red Gums. The wetland now supports numerous Spotted Marsh Frogs and Pobblebonks, with a few Common Froglets. As the wetland vegetation becomes more diverse we may expect the wildlife population to become more diverse also. Hopefully some of the Growling Grass Frogs will find their way upstream to this wetland.

The recordings from this and several other wetlands around Melton were forwarded to Melbourne Water Frog Census, with data sheets attached. A description of this wetland and the surprising diversity of frogs found there, especially the information concerning the threatened Growling Grass Frogs, was also forwarded to the Melton Shire Environmental Department. Growling Grass Frogs are protected under the Environment Protection & Biodiversity Conservation Act 1999 (EPBC Act).
This has since resulted in an EPBC referral prior to a residential development taking place beside this site. This should result in future development here being more frog-sensitive (and as a result more wildlife friendly). This is a positive result from Melbourne Water Frog Census activity.

Thanks to Melton Shire Environmental Department for their alertness in referring the existence of the Growling Grass Frogs. This environmental awareness by Melton Shire should help ensure that future residential development in Melton is conducted in an environmentally sensitive manner. It also shows the value of keeping your local council's environmental department informed of what wildlife is found around your region, especially threatened species.

Daryl Akers

All the frog photos are by Richard Akers,  The Spadefoot Toad photos were taken in August 2007, when we first heard them in Rees Rd.  All the other photos were taken on 21st December 2008 at the Clarkes Road dam.