Friday, June 25, 2010

Why are the leatherbacks classified as critically endangered?

I receive a flyer from the ACF a little while ago and it has been sitting on my desk. It listed 3 endangered and one critically endangered species, which was the Leatherback turtle. I would have thought the long-footed potoroo would be much more at risk of extinction, with a much more localized distribution and a smaller overall population
I was intrigued and I started to read up on the Leatherbacks, and the more I read the more impressed I was by this animal. They're widespread with the largest geographical spread of any turtle, resident in three oceans and travelling as far north as Norway and as far south as the Cape of Good Hope. The species has been around a long time in its current form. More modern turtles have a proper carapace but the leatherback as its name suggests just has tough layers of skin. It is big, the largest reptile after three crocodiles species, and that enables it to stay warm, and it stays warmer than expected for a reptile of its size because of a number of adaptations including the oilness of its flesh.
The definiton of critically endangered isn't quite what I understood it to be. It's a relative term. It means that the population has or will decline by 80% in three generations. That intrigued me. The classfication system is complex, more complex than I thought people would have expected it to be. The terms come from the IUCN Red Book.
The other place to look is the CITES appendices. I hadn't quite got the distinction between the two and that CITES and IUCN are unrelated organizations, and the definitions are determined independently. CITES is only about trade, about controlling trade in animals to conserve them. And the devil (or the angels) in CITES is in the appendices. Leatherbacks are listed in Appendix 1, which outlaws harming or killing of the species. The thing about the appendices is the lower the number the more the the species that is listed is at risk.
The IUCN is a broad-based organization that operates at the level below governments. It has over 1000 organizational members and some 13,000 individual scientists as members. CITES is an international treaty between some 89 governments out of some 200 in the world (the UN has 193 members).
I'm glad I went on that little exploratory journey.

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