About Heleioporus australiacus (Shaw & Nodder, 1795)
Heleioporus australiacus, commonly called the giant burrowing frog, is a large frog species that reaches up to 10 centimetres (3.9 in) in length, and it is the largest frog found in Victoria. Its back is typically grey, dark brown, or black, while its belly is white. It has yellow spots along its sides and a yellow stripe running along the upper lip, extending from the back of the eye to the back of the tympanum; this stripe is pink-orange in newly metamorphosed frogs. The species has rough, bumpy skin. During the breeding season, males often have black spines on their fingers. It has a silver iris and a vertical pupil. Because of its large size and bumpy skin, it is often mistaken for the cane toad, but cane toads lack vertical pupils, and their current range does not overlap with the giant burrowing frog's habitat. This species inhabits sandstone heathland, dry sclerophyll forest, and wet sclerophyll forest, ranging from north of Sydney to eastern Victoria. As their common name suggests, these frogs have burrowing ability. During autumn and spring, usually after heavy rainfall, males call from burrows on the edges of creeks. Their call is a very low-pitched "ou-ou-ou-ou-ou" that resembles an owl's call (which inspired the common name), and each call only lasts one or two seconds. The spines on males' fingers may be used for fighting. Females lay between 750 and 1250 unpigmented eggs, which are deposited either in inundated burrows or under heavy vegetation in dams, ditches, and slow-flowing streams. Tadpoles develop within the stream and leave when it floods. The tadpoles are grey, with grey fins that have light flecks. They grow up to 80 millimetres (3.1 in), making them very large, and they are very slow-moving. Their development takes 3 to 11 months. They have been observed in clear water with a pH between 4.3 and 6.5, and a temperature range of 8.5 to 26.5 °C. Giant burrowing frogs are difficult to locate, and they are best seen at night after thunderstorm activity in summer, or after substantial rainfall.
