Introduction:

One of the more troublesome aspects of ranching cattle in the Top End region of Australia is the threat posed by crocodiles, especially when cattle drink in rivers inhabited by the ferocious saltwater variety.

The Latin name for the salt-water variety is Crocodylus porosus. One big difference from their freshwater cousins is the stubby snout and considerably stouter frame. Saltwater crocs can also grow up to 7m (21 feet) in length as opposed a maximum of around 3m (9 feet) for the ‘freshies’(fresh water crocodiles) and are quite capable of attacking and eating humans, whereas ‘freshies’ won’t pose a threat unless seriously provoked.

Being a reptile, crocodiles are ‘cold-blooded’ relying upon the heat of the sun for their body warmth. This is why you can very often see them basking on riverbanks in the daytime. If they get too hot, they can slip into the water to cool off. They do not have any of the sophisticated body temperature regulation systems that mammals have for example. During the dry season (March-Oct), many crocs are hibernating. Their main time for feeding and activity in general is during the wet season.

They have a keen sense of smell and can be attracted from several miles downstream by a wounded animal. (We were told us how when the centre of the town of Katherine was flooded last year, a 20ft croc was seen heading down the main street in the direction of the butcher’s shop!)

As well as rivers, saltwater crocodiles inhabit coastal estuaries, swamps and may be seen swimming out to sea, but also dwell in billabongs (a large pool of water) and pools well inland, which they reach by river systems during periods of flood and also by limited overland excursions.

In the spring, females will lay 30-80 hard-shelled eggs in a nest created from soil, vegetation and debris located on a riverbank or side of a billabong. She will defend the nest aggressively until such time as the babies hatch, at which point she will carry the hatchlings to the water in her mouth, trying not to swallow any along the way of course!

As with snakes, crocodiles have a ‘bad rap’ with people due to the ferocious ‘monster’ image we have fixed in our psyche and which is reinforced in films and by the media in general. But statistically, one is far more likely to come foul of an automobile accident. In 1986, for example, 2, 873 Australians died in automobile related accidents. Four people died as a result of attacks by crocodiles during the 4-year period between 1982-86.

Vocabulary:

• estuaries
• cold-blooded
• inhabited
• hatchlings

Materials:

Availability of research materials including:

• computers
• reptile resource books
• encyclopedias
• journals to record data and observations

Preparation:

• research saltwater crocodiles’ habitat
• identify key locations of their location on the continent
• identify population density in ‘saltie’ environments
• list other species of animals that cohabitate with the saltwater crocodiles
• investigate a local newspaper for organization of topics, headlines, etc.

Procedure:

• Discuss the parts of a newspaper. Each group will write your own article for the ‘Saltie Times”
• Gather information about saltwater crocodiles and the animals that share their environment. Be sure to credit any resources of information used.
• Articles can be fun, but deal with serious issues of wildlife management, population interaction, etc.
• Keep on track, making sure your articles are accurate.
• Select clip art, computer graphics, etc., to highlight specific articles.
• Summarize the activity with a discussion of each article or feature, emphasizing what you learned about crocodile habitats and interaction with local populations.

Analyze and Conclude:

• Identify three issues that concern saltwater crocodile management and protection, i.e., poaching laws, endangered species laws, etc.
• Explain why it is important to accurately report environmental information to others.
• What are the characteristics of a good environmental reporter?
• Did you follow a newspaper format, utilizing the (5) Ws (who, what, when, where, and why) in each of their articles?
• Does artwork supplement the reports and showcase your creativity?

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