Differentiating Between Freshwater and Saltwater Crocodiles

Australia is a habitat for a wide variety of reptiles, including freshwater crocodiles and saltwater crocodiles. While both species are indigenous to Australia and are recognized predators, saltwater crocodiles, colloquially known as “salties,” are more inclined to attack humans compared to freshwater crocodiles, commonly referred to as “freshies.” For travelers visiting Australia, it's essential to learn how to distinguish between these two species based on their physical attributes, diet, and natural habitats. Understanding how to remain safe around both species is crucial to avoid potential attacks.

Assess the size of the crocodile. One of the primary distinctions between freshwater and saltwater crocodiles lies in their size. Freshwater crocodiles are notably smaller, typically reaching lengths of around two meters, with males reaching up to three meters and weighing a maximum of 90kg. In contrast, saltwater crocodiles can grow up to six or seven meters in length and weigh over 1000kg.

• Saltwater crocodiles are so massive that they are considered the largest reptiles in the world by mass. They often appear imposing both in water and on land, a stark contrast to the smaller freshwater crocodile.

Observe the crocodile's head shape. Take note of the crocodile's head shape to distinguish between freshwater and saltwater species. Freshwater crocodiles typically have elongated, slender snouts, while saltwater crocodiles have broader, thicker snouts.

• Exercise caution if you suspect the crocodile is a saltwater species based on its size; approaching too closely could lead to an attack.

Examine the crocodile's teeth size. Compare the size of the crocodile's teeth to determine its species, as each species has distinct jawlines and tooth sizes. Freshwater crocodiles have straight jawlines with uniformly sized teeth. In contrast, saltwater crocodiles exhibit irregular jawlines with varying tooth sizes, with some teeth nearly twice the size of others.

• Due to their smaller stature, freshwater crocodiles also have smaller teeth compared to saltwater crocodiles.
• If you suspect the crocodile is a saltwater species, refrain from close examination to avoid the risk of an attack.

Identify dietary disparities. Saltwater and freshwater crocodiles have distinct dietary preferences, influenced by their size and respective habitats.

• Saltwater crocodiles, or 'salties,' commonly prey on small reptiles, fish, turtles, and wading birds. They may also target larger prey such as wild pigs, buffaloes, and livestock.
• Freshwater crocodiles, or 'freshies,' typically consume smaller river-dwelling animals like insects, fish, frogs, turtles, waterbirds, and snakes. Occasionally, they may also feed on small mammals.
• A notable distinction lies in their interaction with humans—saltwater crocodiles have been known to attack and consume humans, while freshwater crocodiles rarely exhibit such behavior.

Search for freshwater crocodiles in inland water bodies. Freshwater crocodiles are primarily found in northern Australia, inhabiting lakes, swamps, billabongs, and upstream river sections. While they can tolerate saltwater, they prefer freshwater environments due to the antagonistic behavior of saltwater crocodiles.

• Occasionally, freshwater crocodiles may venture into saltwater areas, albeit infrequently.

Search for saltwater crocodiles in lagoons, rivers, and swamps. This species inhabits estuaries, rivers, lagoons, and swamps, predominantly in the Australian tropics and along coastlines.

• Saltwater crocodiles may be spotted on beaches as well as near saltwater rivers and creeks. Many Australian beaches issue warnings regarding saltwater crocodiles, as they are commonly found along the coast.

Avoid encounters with saltwater crocodiles. These crocodiles exhibit more territorial and aggressive behavior compared to freshwater counterparts. Male salties, especially, defend large territories vigorously and react aggressively to intruders. Conversely, freshwater crocodiles are typically less hostile towards humans and display less territorial behavior, though they may retaliate if provoked.

• Avoid approaching crocodile nests, typically located near riverbanks, swamps, or estuaries, as female saltwater crocodiles fiercely guard their nests.
• Avoid swimming in waters inhabited by saltwater crocodiles due to their territorial nature, and maintain distance if encountering them on land.
• Australian authorities often provide advisories on areas with high saltwater crocodile populations, indicating zones to avoid.

Exercise caution around freshwater crocodiles. While less aggressive than saltwater counterparts, freshwater crocodiles still warrant caution. Avoid provoking them by maintaining distance and refraining from obstructing their paths.

• Although some individuals swim in freshwater crocodile habitats without incident, exercising caution is advised.
• Avoid proximity to freshwater crocodiles during their breeding season, particularly in July and August, when females may display heightened aggression and territoriality.

Remember freshwater crocodiles are protected species. Freshwater crocodiles are protected in Australia, with an estimated population of around 100,000 individuals. Habitat loss poses a significant threat to their survival.

• Saltwater crocodiles also enjoy protected status, yet poaching and aggressive trapping have escalated aggression among male individuals in recent years as they vie for territory. While protected, a regulated number of animals and eggs are collected annually under permits issued by State and Territory Governments.