Animal of the Week -- October 1, 2007

Hello one, hello all,

There are probably more than just a few fans of Sandi Toksvig (and no that is not code) among the readership of AOTW, so I would like to apologise up front for the recycling of a joke made by the diminutive Dane on the News Quiz last week. The joke will naturally stick out like a sore thumb among the remainder of my humourless rambling.

This week's animal is Crocodilus porosus (saltwater or estuarine crocodile), the largest reptiles alive in the world today. All around the eastern Indian Ocean and into parts of the western Pacific, these humongous reptiles inhabit the coastal waters and freshwater swamps, rivers, lakes, and billabongs. Pretty much anything is on the menu for salties, from dragonflies and tadpoles for the chicks, to people, dingoes, leopards, kangaroos, and water buffalo for adult males. The largest male ever recorded was 8.6 m (28.3 ft) long, for such a beast Toksvig would have been a mere morsel.

Saltwater crocodiles are thought to be the only animals that think of people as regular prey and they cause about 300 deaths worldwide annually. Although the big question is who would win in a fight between a shark and a crocodile. The largest great white and the largest bull saltie are well matched in size, although sadly for them as love a good "who would win discussion", they'd never meet, crocodiles having a tropical range (and the largest ones mostly fresh water) and great whites being animals of temperate regions. Should the crocodiles meet the slightly more diminutive tiger sharks, the two would probably ignore each other, both preferring easier prey, the shark might take smaller crocs, and the croc maybe smaller sharks (see pic).

Of the 23 species of crocodile or alligator in the world today, the saltie is the least endangered, although in parts of south Asia and the Pacific these magnificent beasts have become locally extinct due to habitat loss and conflict with people Fortunately the vast empty expanses of northern Australia and New Guinea and these animals remarkable ability to disperse through deep ocean water means that the species should be safe.

Where they do come into conflict with human beings in Australia, policy has been to transport them from residential areas and pleasure beaches to areas not frequented by people. However, researchers tracking relocated animals were surprised to discover that some had navigated up to 150 miles to make it back to the area from where they were removed. Turns out that saltwater crocodiles, particularly the males, are highly territorial. They travel great distances through rivers and coastal waters to find patches not already inhabited to which they can stake their claim and once they find them, they stick to them.

Will this discovery see Yorkshire folk forsaking their homing pigeons in favour of these distant relatives of birds for crocodile races? Probably not until global warming really kicks in. Although the ability of these cold-blooded, dangerous, ancient reptiles to traverse great distances to navigate home after long periods of time does at least explain Margaret Thatcher's recent reappearance at Number 10 (thanks Toksvig).

Bye!