The Shiant Isles has recently been declared rat-free. During a four-year programme to eradicate the rodents, the Royal Society for the Protection of Birds (RSPB) placed traps filled with cocoa and peanut butter-flavoured wax blocks to catch them.
This project has been focused on making the island rat-free to support the seabird populations providing additional protection for the birds who breed on the islands.
Two years after the completion of the project there is no evidence of rats meeting the internationally agreed criterion for rat-free status.
The Isles are a group of islands five miles east of the Outer Hebrides and form one of the most important seabird breeding colonies in Europe, providing a home for around 100,000 pairs of nesting seabirds each year.
The rats were not native to the islands and were thought to be the descendants of rats that came ashore from shipwrecks in the 1900s. Over the years the rats on the islands were feeding on eggs and chicks of the birds that breed there, including puffins, razorbills, and guillemots.
At the other end of the world in South Georgia, an island off the tip of Antarctica teeming with penguins, seals and rare birds, another initiative to eradicate rats has also been a success story. It was once home to five million rats but now it has zero.
It took over 10 years to reduce the rat population to zero by dedicated team members who dropped rat poison from helicopters and used three rodent detection dogs to rid the island of rats that had been devastating the wildlife for over 200 years.
South Georgia is an incredibly mountainous place. It’s only a hundred miles long, which doesn’t sound massive, but it’s like a section of the Alps have been chopped off and dropped into the ocean. All around the edge of the island are pockets of greenery and vegetation, and that’s where most of the animals and bird life live.
The island was first discovered by Captain Cook who reported back to England saying that this was a real haven for seals. Sailing vessels began to head down to South Georgia to harvest the seals and take the skins. The ships were infested with rats as most ships at this time were and the rats found the island an ideal home.
The rats on the island were basically eating anything in sight. South Georgia is an island without trees so any bird on the island nests on the ground or it nests under the ground and burrows. As a result, South Georgia became a free for all for the rats to eat the chicks and eggs.
The latest war on rats is taking place in New Zealand where they are planning to be rat free by 2050.
In this corner of the South Pacific about 80 per cent of New Zealand’s bird species are at the risk of extinction. Recently, there has been a decisive cultural shift in the attitudes of New Zealanders resulting in the project becoming mainstream.
Perhaps the growth of the global rat population is now on the wane but don’t get too excited.
There are over 11 million rats in the UK and in New York the population is estimated to be around 8.5m.
Gordon is the former president and chief executive of BMMI. He can be reached at firstname.lastname@example.org