Crocodilians: Natural History & Conservation: Crocodiles, Caimans, Alligators, Gharials

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Crocodilian images which reveal fascinating stories told from a visual perspective.

CROCODILIAN SPECIES LIST

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Master of the Air-Water Interface

Baby saltwater crocodile floating

June is a difficult month for baby saltwater crocodiles. Nearly all the saltwater crocodile nests in the Northern Territory of Australia have hatched by now, although only a quarter of all eggs laid will result in viable, live hatchling crocodiles. Once free of the confines of the egg, the crocodiles have a tough struggle to survive. Staying close to the water's edge, hidden amongst the vegetation, they must keep a watchful eye out for the predators who would eat them - monitor lizards, birds such as Jabiru storks and fish eagles, large fish such as barramundi, and worst of all... other saltwater crocodiles! Although their mother will protect them for several weeks after hatching, other adult crocodiles care not for the fate of others' young and will eat them as readily as any other prey item.

Cannibalism has been observed in many crocodilian species, and probably exists in them all. In saltwater crocodiles, at least, it is not as barbaric a mechanism as it sounds, and in fact is an important factor in controlling population growth. When populations of saltwater crocodiles are healthy, there is much nesting and many hatchlings enter the population. However, with insufficient habitat and resources to support them all, it is beneficial for the existing population if few of these hatchlings survive very long. If the population is depleted, however, there will be fewer adults to prey upon the hatchlings, and survival of the young becomes much greater - an adaptive mechanism to ensure faster recruitment of young into the population to aid recovery of numbers. This has been in operation in the saltwater crocodile population in the Northern Territory, whose numbers were greatly depleted by extensive hunting between 1945 and 1971. High survival of the juveniles in the 70's following protection has led to a rapid recovery of the population which now approaches the carrying capacity of the habitat in many areas, l eading of course to greater cannibalism of the young once again. This is bad news if you're a baby saltwater crocodile, but good news for saltwater crocodiles in Australia as a whole - a testament to their ability to survive.