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Not much is known about the status of reptiles as a whole. Of more than 8,700 species, only 1,386 have been evaluated by the IUCN Red List of Threatened Species, and 180 of those are still deemed data deficient. Of the remainder, 35% of reptile species worldwide that have been evaluated by the IUCN are threatened:
203 species are listed as Vulnerable
134 species are listed as Endangered
86 species are listed as Critically Endangered
Many reptile species have remained almost unchanged for hundreds of millions of years, yet are now in danger of extinction due to the ecent activity of humans. This can be directly through hunting, or indirectly, through the destruction of their natural habitat. The most common threat to reptiles has been the introduction of invasive species by humans, such as predator species, or plants that have drastically changed the reptiles’ habitat.
In the last year alone, seven species of reptile have shown genuine deterioration in status and had to be re-categorised by the IUCN:
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Species | Distribution | 2007 IUCN Red List Category | 2008 IUCN Red List Category | Threats |
Cuban Crocodile
Crocodylus rhombifer
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Cuba
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Endangered
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Critically Endangered
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Illicit hunting, hybridisation with native American crocodiles
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Madagascar Big-headed Turtle
Erymnochelys madagascariensis
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Madagascar
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Endangered
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Critically Endangered
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Hunting for subsistence, fishing bycatch
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Radiated Tortoise
Astrochelys radiata
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Madagascar
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Vulnerable
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Critically Endangered
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Hunting for food and international trade, habitat destruction
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Ploughshare Tortoise
Astrochelys yniphora
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Madagascar
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Endangered
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Critically Endangered
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Hunting for international trade, human-caused fires
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Spider Tortoise
Pyxis arachnoides
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Madagascar
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Vulnerable
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Critically Endangered
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Habitat destruction, hunting for food
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Flat-tailed Tortoise
Pyxis planicauda
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Madagascar
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Endangered
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Critically Endangered
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Habitat loss from fire and agriculture, hunting for trade
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Data from IUCN (2008)
No species have shown genuine improvement.
Those species most in danger are island species, such as the Philippine forest turtle (Heosemys leytensis), which usually have evolved without predation and human interference for millions of years. Not only are they often unable to adapt quickly to a change in their habitat, but they have nowhere to go, and so cannot spread or move to a more suitable area.
Continue on page 6
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The gharial Gavialis gangeticus is a critically endangered species throughout its restricted range. © Paddy Ryan
The rare African spurred tortoise Geochelone sulcata occupies the southern edge of the Sahara desert.
© Eunkyung Chae
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