Chelodina (Macrochelodina) expansa
Broad-shelled river turtle, Broad-shelled snake-necked turtle
Least Concern (nationally), Vulnerable (SA), Threatened (VIC)
The Broad-shelled turtle is the largest freshwater turtle in Australia, and the largest long-necked turtle species on Earth. It has a broad, oval carapace getting up to 50cm in length, and females are typically larger than males. Rich brown to blackish above, they can also have very fine patterning. The plastron and underside is usually more of a creamish colouration. They have a broad and flattened head, with eyes and nostrils right at the front. The neck may actually be longer than the carapace when full extended, but is usually around 36cm when fully grown.
Being a long-necked turtle species, they are completely carnivorous. Common prey items are frogs and tadpoles, crustaceans such as yabbies and small crayfish, aquatic insects and fish, although due to their large size, larger prey items such as lizards and ducklings can be taken. Long-necked turtle species are known to ambush small bird species drinking at the water’s edge, rapidly extending their neck and striking out explosively to snatch unsuspecting prey and drag them beneath the water’s surface.
This species prefers murkier waters in areas three metres deep or more. They can be found in permanent water sources such as rivers, ponds and swamps. They prefer living in waters with lots of structures present, such as logs, root systems and fallen trees. They also prefer undisturbed environments out of the water, with lots of groundcover for when nesting occurs.
Broad-shelled turtles are found throughout the Murray-Darling River system of south-eastern Australia. A number of distinctive populations have been located across central and coastal Queensland areas.
Mostly active from about October through till April. Over the winter months, they do not move around or eat as much as temperatures wouldn’t allow these ectotherms to digest their food properly. They spend most of their time underwater, although when water levels drop, they have two strategies for survival. Some will come out of the water and move over land to find a new water source. Others may choose to bury themselves in the mud and enter an extended period of aestivation until the water levels rise again.