REMARKABLE REPTILE REPORTS

Reptiles fascinate people, no doubt about it. They are beautiful, weird, scary, wily, sometimes dangerous and very good at adapting fast to their environment. They are not usually thought of as invasive species, though, but a cobra found on São Tomé in the Gulf of Guinea off West Africa, called locally the cobra-preta, was thought to be an exotic invader – that is until genetic analysis proved otherwise. Until now, people thought it had been introduced to the island to control rats but, as it is a deadly species that can grow to 3m in length, scientist Luis Ceriaco felt that was unlikely. Because of his work, this snake has now been correctly reclassified as a new species, Naja peroescobari, endemic to the island and not invasive at all – still deadly though.

Staying with snakes, in another story reported in New Scientist and the Journals, some populations of the colubrid Japanese tiger keelback snake (Rhabdophis tigrinus) have been found to sequester toxins from the prey they eat (toads) that the snakes store in specialised nuchal glands. This confers a defence to the snakes’ own predators which would receive a dose of toxins if they attack.  On some islands in its range these snakes and the toxic toads are sympatric; on other islands the toads don’t occur and the snakes’ prey is different and is toxin-free. Fascinatingly, researchers Akira Mori and Gordon Burghardt have found that only snakes that had stored toxins from toads stood their ground and were aggressively defensive when attacked; those without stored toxins fled. It seems that the snakes change their behaviour when they “know” they are loaded with acquired toxins. This is thought to be unique amongst reptiles.

Another recent story in the herpetological press is about the discovery of nineteen new species of gecko.  Most of us love geckos; I do anyway, as they are charming and often extraordinarily agile and colourful reptiles. We have one species, the Moorish gecko Tarentola mauritanica, in the house and office in France that I have written about elsewhere. All these new species, though, have been found by herpetologist Lee Grismer in a single locality, a small area of Burma (now called Myanmar) of just 50km by 90km. It is astonishing to find so many species of this lizard in such a small area.  The landscape in which they live has huge blocks of sculpted, cave-rich limestone rising to 400m above the plain where the geckos are safe from predators. In isolation in the plain, the limestone blocks are isolated habitats that have become islands of evolution (think Darwin’s Galapagos finches).

You can find pictures of some of these newly-discovered geckos here: https://tinyurl.com/y99xmjyj but below is the Moorish gecko photographed by Dr Betts in France.