Why are there no snakes in Ireland? The legend and the science

It’s almost that time of the year again when Ireland’s patron saint, St. Patrick, is celebrated across the world. But did you know he rid the island of snakes?

If you’ve ever been to Ireland, you might notice that the Emerald Isle is free from wild snakes. In fact, it’s one of only a handful of countries in the world – including New Zealand, Iceland, Greenland, and Antarctica – to have no native snake population!

But have you ever wondered why? If so, you’ve come to the right place. Keep reading to find out the Irish folklore and the scientific reasons why there are no snakes in Ireland.

The legend

The patron saint of Ireland and the myths of the snakes has been a huge cornerstone of Irish mythology.
Saint Patrick

According to legend, it is believed that Ireland’s patron saint, St. Patrick, rid Ireland of its snake population in the 5th century AD when he was on a mission to convert the country’s people from paganism to Christianity.

It is said that the Christian missionary chased the snakes into the Irish Sea after they started attacking him during a 40-day fast he undertook on top of a hill.

Since then, snakes have not lived on the island of Ireland.

The science

There are no snakes in Ireland because several ice ages made life unsustainable for snake populations.

While it’s a great tale, the story of St. Patrick banishing these slithering reptiles from Ireland is unfortunately not the real reason why the island is free from snakes.

In fact, it’s more to do with the Irish climate – hey, it had to come in useful somehow!

About 100 million years ago, when snakes first evolved, Ireland was still submerged underwater, so the reptiles were unable to make the island their home.

When Ireland finally rose to the surface, it was attached to mainland Europe, and thus, snakes were able to make their way onto the land.

The cold climate is considered to be the main reason why there are no snakes in Ireland.

However, about three million years ago, the Ice Age arrived, meaning that snakes, being cold-blooded creatures, were no longer able to survive, so Ireland’s snakes vanished.

Since then, scientists estimate that the European climate has changed around 20 times, often blanketing Ireland with ice. This made the conditions of the island unstable for cold-blooded reptiles, such as snakes, to survive.

According to scientists, the last time Ireland was covered with ice was in the previous ice age, about 15,000 years ago, and since then the climate has stayed pretty much stable. So why are there still no snakes in Ireland all these thousands of years later?

By this last ice age, Ireland became separated from the rest of mainland Europe causing a 12-mile water gap – the North Channel – between Ireland and Scotland. This made it impossible for snakes to reach the island.

So why does St. Patrick get all the credit?

St. Patrick gets the credit for their being no snakes in Ireland, when really he had nothing to do with it.

According to Nigel Monaghan, naturalist and keeper of natural history at the National Museum of Ireland in Dublin, “At no time has there ever been any suggestion of snakes in Ireland, so [there was] nothing for St. Patrick to banish.”

It is unknown from where precisely the legend came that St. Patrick was to thank for ridding the Emerald Isle of its snake population, but many people believe that snakes were, in fact, a metaphor for paganism.

St. Patrick was a Christian missionary in Ireland in the 5th century, and many people believe that the legend that he rid the island of its snakes is actually a metaphor for his role in banishing the druids and other pagans from the island of Ireland.

Paganism and St. Patrick today

Many believe the fact there are no snakes in Ireland is symbolic for St. Patrick banishing paganism from the country.
Credit: Steven Earnshaw / Flickr

Many pagans today refuse to celebrate holidays which celebrate the elimination of one religion in favour of another so many choose to wear a snake symbol on St. Patrick’s Day.

If you see someone wearing a snake badge on their lapel this March 17th instead of the usual shamrock or ‘Kiss Me I’m Irish’ badge, then now you know the reason why!

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