The Australian Freshwater Crocodile is a medium-sized crocodile species found in the Northern parts of Australia.
They inhabit freshwater habitats such as rivers, lakes, and swamps. They are generally smaller and less aggressive compared to their larger relative, the Saltwater Crocodile.
They primarily feed on fish, crustaceans, and smaller prey. As a result, they are less likely to be a threat to humans than the Saltwater Crocodiles.
Australian Freshwater Crocodile Taxonomy
In the Animal Kingdom, Taxonomy is used as the science and practice of classifying different species and sub-species based on their biological and genetic makeup.
Family
The family that the Australian Freshwater Crocodile belongs to is called Crocodylidae. This is the family of True Crocodiles native to the tropical and sub-tropical areas of the world.
These Crocodiles can be found in places such as Africa, Asia, the Americas and Australia.
There are currently 3 recognised genera and a total of 18 recognised species in this family.
There are more species in the Crocodilia Sub-Family such as Alligators and Caiman but these species aren’t considered ‘True Crocodiles’.
The most obvious external differences are visible in the head, with Crocodiles having narrower and longer heads, with a more V-shaped than a U-shaped snout compared to Alligators and Caimans.
Genus
The genus that the Australian Freshwater Crocodile belongs to is called Crocodylus. While some sources consider the 3 genera of Crocodylidae as ‘True Crocodiles’, the species in this genus really are the ‘True Crocodile’ species.
There are currently 13 recognised species in this genus and a few recognised sub-species. There are also 5 extinct species in the genus.
The Crocodylus genus likely originated from Africa with species spreading towards South-East Asia and the Americas. However, some scientists believe their roots can be traced to Asia and Australia.
Species
The scientific name for the Australian Freshwater Crocodile is Crocodylus johnsoni and there are currently no recognised sub-species.
This species was first described in 1873 by an Australian naturalist named Johann Ludwig Gerard Krefft.
Some literature describes the species as Crocodylus johnstoni instead of johnsoni. However, they are referring to the same species.
Australian Freshwater Crocodile Description
The Australian Freshwater Crocodile is a relatively small species of crocodile when you compare it against the larger Australian Saltwater Crocodile.
Adults typically reaching lengths of around 2 to 3 meters (6.5 to 10 feet) although some individuals occasionally growing a bit larger.
They have a slender and elongated body with a streamlined, V-shaped snout. This snout shape distinguishes them from the broader, almost U-shaped snouts of saltwater crocodiles.
Their coloration is light olive to brownish-grey. One of the distinct features of the Australian Freshwater Crocodile is the presence of dark bands or irregular spots along their back and tail.
These bands or spots are often more noticeable in younger individuals and tend to fade as the crocodile ages.
They have relatively long limbs with webbed toes that are adapted for swimming. Their tails are muscular and strong, enabling efficient propulsion through the water.
Their eyes and nostrils are positioned on top of their head, allowing them to remain almost fully submerged while they come to the surface.
The Australian Freshwater Crocodile has sharp teeth designed for capturing and holding onto their prey.
Natural Habitat and Distribution
The Australian Freshwater Crocodile has a limited geographical distribution primarily within the northern parts of Australia.
Their geographical distribution extends through parts of Queensland, the Northern Territory and Western Australia.
They are predominantly associated with freshwater habitats such as rivers, streams, lagoons, and swamps.
They tend to prefer habitats with relatively clear freshwater. They prefer freshwater habitats as opposed to saltwater or brackish environments.
These crocodiles are often encountered in the freshwater sections of rivers and in various wetland ecosystems in northern Australia. They are well-adapted to these environments and can be seen basking along the banks.
Australian Freshwater Crocodile Behaviour
The Australian Freshwater Crocodile is generally less aggressive than their larger relative, the Saltwater Crocodile.
Freshwater Crocs are known to be shy and often bask in the sun on the banks of rivers and other sources of water.
They are more active during the day and are considered territorial, particularly during the breeding season.
Their diet consists of small vertebrates, including fish, frogs, insects, and occasionally birds. They are skilled hunters, using stealth and patience to catch their prey.
The Australian Freshwater Crocodile will breed during the wet season. Females build nest mounds near the water’s edge and lay eggs.
After incubation, the mother assists the hatchlings in reaching the water. They are protective of their nests and young.
