The puffins and rats of Lundy

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Lundy Island is a tiny island in the Bristol Channel and it’s made of granite rock, so it’s got quite high cliffs and a sort of flattened top with sort of grassy vegetation on it and lots of herbaceous plants.

Well, Lundy was a very important breeding site for puffins, and indeed for other seabirds, in particular Manx shearwaters. Both species like to, well they have to nest in burrows. They use burrows that were there already, probably made by rabbits, and they do indeed compete with each other in order to occupy those burrows. But the whole point of seabirds breeding on these isolated islands is, of course, that there’s no land-based mammalian predators there, and these birds are very vulnerable to predation by species such as foxes, badgers, rats, because they can simply come into the burrow or dig the burrow out and help themselves to the contents, and then that’s it - whereas with the bird predators, which hunt from the air of course, the chicks are actually hidden in the burrows so the young birds are not at risk of predation.

Since the birds have been co-existing quite happily with the rats, apparently for many hundreds of years, it was quite controversial at the time to start this eradication programme but, in fact, the numbers of puffins had dwindled to virtually zero and something had to be done. And, of course, there’s the other species, the Manx shearwaters, which we shouldn’t totally forget about because they have the similar habit as the puffins of nesting within the burrows, and they are also very threatened by land-based predators. And as a country we do have a responsibility to look after our population of Manx shearwaters because we have quite a high proportion of the total numbers breeding on Lundy, so it was our responsibility to eradicate those predators.

The scheme went ahead, and it was a collaborative project. There was the RSPB, the Landmark Trust and Natural England all working together and, what they did was, they set up a grid over the whole island and placed baited traps within each grid, and then people went and examined the traps every day to check. And this was started in the year 2001. Certainly, by 2003/2004 there were no rats left on the island at all. Although the Manx shearwater numbers have increased reasonably well, the puffins have been much slower to return to the island, and I can give you an idea of how sort of fragile this is; in 2008 there were six active nests observed. Just six. And you compare that to the 3,900 pairs that were nesting on the island reasonably recently - 1939 - it’s not that long ago.

Remember that the puffins’ life can last for up to 30 years, so in fact they could well have been experiencing breeding failure for some years before it was noticed, because they would still be coming to the island, they would lay the eggs, but on the other hand all of the chicks might not have survived, so it would have been a very slow, initially a very slow decline.