Lundy is a small island 11 miles off the coast of Devon, in south-west England. At time of writing, early in 2003, it is inhabited by one of the only two remaining established colonies of ship rat in Britain (the other being on the Shiant Islands in the Hebrides), as well as the usual/inevitable raffish collection of Norway rats.
Until the mid 18th C the ship rat, a.k.a. The Old English Rat, was the only rat in Britain: it is the rat of legend, the rat mediaeval barns were rife with. The Lundy rats are believed to have swum ashore from a shipwreck of the Spanish Armada. They are unusually small - about gerbil-size - and have a high proportion of white-bellied agoutis, a colour very rare elsewhere in the world. They cohabit amicably with the neighbouring Rattus norvegicus colony, disproving the Victorian idea that the invading Norway rat deliberately killed the native ship rat (rather than out-competing it).
The ship rat colony has lived on Lundy for 400+ years, and the Norway rat colony has been there for about 200 years, without apparent ill effect on the island's puffins and Manx shearwaters. In the last few decades, however, seabird numbers have fallen.
Dr Keith Hiscock, marine biologist and long-standing member of the Lundy Field Society, reports that the rare and interesting sea-life all around Lundy is in sharp decline as at spring 2003. Since the seabirds on Lundy are fish-eaters, one need look no further than the decline in nearby fish-stocks to explain the decline in birds.
Occasional predation of bird-chicks has been reported - in an area well away from either rat colony, on an island inhabited by gulls, peregrine falcons, domestic cats and deer (who kill ground-nesting birds and suck out their bones for the calcium to make antlers).
R. rattus is primarily vegetarian, and the Lundy strain are tiny and very lightweight in build. Some years ago a couple called Joan and Roger Branton ran a ship rat domestication project using animals wild-caught on Lundy, and found that these rats had no interest in meat and and were unable to recognize bird-eggs as food.
However, the Lundy Seabird Recovery Project, a coalition between English Nature, the National Trust, the Royal Society for the Protection of Birds (R.S.P.B.) and a tourist organization called the Landmark Trust, has decided the fall in seabird numbers must be due to predation by the ship rat. The sole evidence is that two ship rats were found to have feathers in their stomach contents: unsurprizing, since rats are scavengers and the island is littered with the carcases of seabirds killed by gulls.
The L.S.R.P. claims there are "up to" 40,000 rats on Lundy: but repeated scientific surveys have put the ship rat colony at around 400 individuals (the normal size for a wild rat colony), plus a similar number of Norway rats.
If the rats were predating on seabirds it might be desirable to cull them to relieve pressure on the bird colonies, even if the decline in birds was due to lack of fish. But one could equally say a decline in seabird numbers is a good thing because it relieves pressure on the increasingly rare fish.
Nor is extermination neccessary even if the ship rats were taking eggs. The Shiant population is maintained at around 200 individuals by judicious culling, and cohabits with the local seabirds without harm. But since January 2003 the L.S.R.P. has been attempting to poison all the rats on Lundy, using second-generation rodenticides not licensed for outdoor use. These will not only cause suffering to the rats but will get into the food-chain and kill the islanders' cats, as well as any birds which scavenge on the carcases of poisoned rats.
The L.S.R.P. regards the ship rats as of no scientific interest because they are "not indigenous". However, ship rats probably came to Britain with the Romans - i.e. they've been here as long as brown hares, and twice as long as rabbits, both of which we treat as native species.
Worldwide ship rats are not endangered: indeed they are one of the commonest mammals on earth. But they are probably the rarest mammal in Britain, with a total population less than 1,000 - and it's a crying shame to wipe them out: especially as there's no scientific evidence that doing so will do the seabirds of Lundy the slightest good.
The real reason for this mass extermination is that the Landmark Trust, which promotes bird-watching holidays, feels that the rats are untidy and bad for tourism. In fact ship rats are pretty and playful creatures, and Britain's rarest mammal would be a major tourist attraction in its own right if they would only promote them properly. This is the preferred option of the Lundy Field Society.
[It occurs to me that the Landmark Trust's increasing promotion of Lundy as a tourist destination must mean an increase in the resident human population, to cater for those tourists. An increase in the human population nearly always means an increase in the cat population - and cats, much as I love them, are the major predator on British birds.]
The British charity Animal Aid has produced a leaflet campaigning against the extermination. For copies of this leaflet, and further details of how you can help, please 'phone their office on 01732 364 546 ext. 29, or e-mail them at firstname.lastname@example.org.
Anyone who is concerned about the destruction of this unique colony should write a.s.a.p. to the following organizations, and to the Britsh press: