The Puffin colonies on Ailsa Craig and on the
From the
records held by the Arran Natural History Society there are signs that the
number of sightings in
There is no
doubt in my mind that a major factor contributing to this was the outstanding
work of Dr Bernard Zonfrillo and his team in eradicating rats from Ailsa Craig.
In 1871, the Puffin colony on Ailsa Craig was
described as in "bewildering numbers... so great that they darkened the
sky" . But by 1934 they were
"practically extinct". What
happened in between was that rats from ships had been introduced. The first rat was recorded in 1889, and a year
later the light-keepers killed over 900 rats. "They are all over the
island, from the very top down to the water's edge". Puffins nest in burrows and once the egg is
hatched both adults go regularly to sea for fish for the young chick. This makes the young particularly vulnerable
to rats.
Attempts to eradicate the Ailsa Craig rats
were carried out in the 1920's, but they failed due to the poisons used being
ineffective. Ailsa Craig was infested by
rats until 1990 when Dr Zonfrillo and his team got involved. On 15 April 1991 the last live rat was seen on
Ailsa Craig.
To find out
how this was done, with the aid of over five tons of lethal Warfarin
rodenticide, a Sea King helicopter, a lot of hard work and a systematic
monitoring program over years, I recommend this article by Dr
Zonfrillo “Before and After the Eradication of Rats” on the Ayrshire Birding
Website
After more that ten years of monitoring work, it was success at last. Non-breeding Puffins always outnumber breeding
pairs but the increase continues. This
year (2008) on occasions there have been over two hundred Puffins around Ailsa
Craig, all potential future breeders. The future looks bright for Puffins in the
As Dr
Zonfrillo says, “It's not just the Puffins that are benefiting since the rats
were exterminated. Other sea-birds on
Ailsa Craig are successfully producing more chicks, plus rare plants, other
mammal species such as Pygmy Shrews and even the island's reptiles, Slow Worm and
Common Lizard are flourishing again, now the rats have gone.”
Based
on the experience of Ailsa Craig, it is interesting to speculate if the rats
and mink could be exterminated on Pladda or