An Aesculapian Snake (Zamenis longissimus) Photo by By FelixReimann – Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=7433690

Dear Readers, the UK has three native snakes species (the Grass Snake, the Smooth Snake and the Adder), but for a long time it’s been known that there is a population of a fourth species, the Aesculapian Snake, hanging around the Regents’ Canal in central London very close to London Zoo. The Zoo maintains that the snakes did not come from them, but from a local facility that bred the animals, from where they were either released or escaped. I have spent many cheery minutes surveying the undergrowth by the side of the canal to see if I could see a snake, but no luck so far. There are thought to be about forty individuals of these attractive snakes, and with climate change bringing warmer weather there’s every chance that they might thrive. They are about 2 metres long and live on small mammals, which they kill by constriction – the snakes are totally harmless to humans.

As you might have guessed, the Aesculapian Snake gets its name from the staff of Aesculapius, the Greek god of medicine – because snakes shed their skins, and are hence re-born, they were thought to be a symbol of healing. A few isolated populations of the species are believed to have been taken to the location by the Romans, who used the snakes in some of the rituals in Temples of Aesculapius.

Aesculapius with his staff (and snake) from the Museum in Epidauros (Photo by By original file by Michael F. Mehnert – File:Asklepios – Statue Epidauros Museum 2008-09-11.jpg, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=8718607

Anyhow, it turns out that the snakes on the Regent’s Canal are not the only ones in the UK. A population escaped from the Welsh Mountain Zoo near Conwy in Wales, and there are apparently some others hanging out in Brigend. The Conwy population has nearly 70 individuals. But how are these snakes, native to the warmer parts of Europe, doing in our still relatively-chilly climate? Apparently they are excellent climbers, and often find their way into outbuildings and attics for the winter, according to a study by Tom Major at Bournemouth University.

Aesculapian snake in a tree in Austria (Photo By Christoph Leeb – Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=6971873)

Major attached trackers to 21 snakes and then released them. He found that almost all the males preferred to hang out in gardens and buildings, while the females preferred woodland, although they liked to lay their eggs in compost heaps. Sadly, six of the snakes being tracked died during the study – three were run down by traffic, including two pregnant females – Major hypothesises that they were looking for somewhere to lay their eggs. Three snakes were taken by predators, with one tracking device ending up in a buzzard nest, evidence of how versatile these birds of prey can be.

Incidentally, the young snakes look very different to their parents and I suspect could be easily mistaken for adders by the unwary. As adders are venomous I fear that this might lead to casualties inflicted by those lacking knowledge of how shy and retiring all of our reptiles are.

Young Aesculapian snake (Photo CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=291070)

I take issue with the New Scientist’s headline that this is an ‘invasive’ species, however. The three populations are small in size, and haven’t increased worryingly in all the time that they’ve been here. There is quite enough animosity towards snakes, without stoking it further. In fact, I have written to New Scientist to complain. I shall be interested to see what they say. Harrumph!