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Friday, March 16, 2007

St. Patrick Banished Snakes from Ireland

Friday's Urban Legend: FALSE

Connie Barlow describes A St. Patrick's Day Parable.
Ireland is a land of no snakes. It has no slithering serpents. There are no rat snakes in Ireland; there are no rattlesnakes; there are no garter snakes. There are no snakes at all.

The absence of snakes in Ireland seems to cry out for an explanation — but only if one regards or ventures to the island from outside: from England, say, or from continental Europe. To the indigenous Celts, there would, of course, have been nothing to explain. The Gaelic peoples no more needed to explain an absence of snakes on their island home than they needed to explain an absence of kangaroos. To those who came to Ireland from abroad, however, a dearth of serpents was a striking anomaly in need of an answer.

We humans must have answers. And so arose the legend of St. Patrick and the snakes. The reason Ireland has no snakes, the story goes, is that Patrick charmed all snakes on the island to come down to the seashore, slither into the water, and drown. So Ireland did once have snakes, but it has them no more. Patrick charmed them all into the sea.
She goes on to explain why there are no snakes in Ireland but I prefer to swtich to the website of the Smithsonian National Zoological Park for their explanation of Why Ireland Has No Snakes.

Now snakes are found in deserts, grasslands, forests, mountains, and even oceans virtually everywhere around the world. Everywhere except Ireland, New Zealand, Iceland, Greenland, and Antarctica, that is.

One thing these few snake-less parts of the world have in common is that they are surrounded by water. New Zealand, for instance, split off from Australia and Asia before snakes ever evolved. So far, no serpent has successfully migrated across the open ocean to a new terrestrial home. As the world's oceans have risen and fallen over the millennia, land bridges have come and gone between Ireland, other parts of Great Britain, and the European mainland, allowing animals and early humans to cross. However, any snake that may have slithered it's way to Ireland would have turned into a popsicle when the ice ages hit.

The most recent ice age began about three million years ago and continues into the present. Between warm periods like the current climate, glaciers have advanced and retreated more than 20 times, often completely blanketing Ireland with ice. Snakes, being cold-blooded animals, simply aren't able to survive in areas where the ground is frozen year round. Ireland thawed out for the last time only 15,000 years ago. Since then, 12 miles of icy-cold water in the Northern Channel have separated Ireland from neighboring Scotland, which does harbor a few species of snakes. There are no snakes in Ireland for the simple reason that they can't get there.

[The book cover is from a book by Sheila MacGill Callahan (Author) and Will Hillenbrand (Illustrator). You can buy it on]


  1. I understood that Hawaii is now having problems with snakes, which were introduced to the islands, there being no native snakes, and therefore no native defenses against snakes.

    Is this true?

  2. Yes indeed:
    It surprises me that a similar problem has not arisen in ireland (or maybe it has and I haven't heard about it.)

  3. According to Carl Zimmer in his book 'Evolution' pythons arrived on Krakatau successfully crossing 27 miles of sea from the mainalnd after the eruption

  4. OK, so St. Patrick and the snakes is just a legend. But what about St. Urho, who drove the grasshoppers out of Finnland?

  5. It'd be cool if somebody found fossil snakes, but knowing almost nothing about Ireland's geology, I don't know if that's possible.