Longtail project success on Calf

RODENT CONTROL: Volunteers take a break from setting traps designed to rid the island of brown rats.

RODENT CONTROL: Volunteers take a break from setting traps designed to rid the island of brown rats.

  • by Kate Hawkins

Work on the Calf longtail eradication campaign is not for the faint-hearted.

With around 1,025 bait points to service, there isn’t much time to sit around and contemplate the scenery, though there are days when it’s good to pause in your toil to take in the dramatic land and seascape.

Weather seldom daunts the properly wrapped up and shod, though it can be hard going through knee-high heather and bramble thickets.

All field workers are equipped with waterproof equipment, including notebooks, and everybody is well-briefed about hygiene and personal safety.

Walkie-talkies keep people in touch with each other, leading at times to some bafflement at Cregneash, where MNH staff occasionally pick up stray messages from the Calf.

At least after a long hard day there is the warmth of the observatory wood stove to go back to and some catching up with the day’s findings over a brew and hot meal.

Life on a small island forces you to think about sustainability. Fresh water comes from a well and is in limited supply, and all fuel for electricity generation and cooking has to be brought over by boat.

Conversely, all non-burnable or compostable waste (including waste bait) needs to be taken off the Calf for recycling or disposal, which generally makes us more conscious of the waste we are generating while we are out there.

Just before Christmas, non-toxic wax blocks flavoured with chocolate were added to the bait points. These show up teeth marks of any investigating rodents and are vital for detecting any residual longtail activity.

To date, only a few blocks have been found with teeth marks on them, one nibbled by a longtail, others by mice and the occasional rabbit.

In March, the rodenticide in the bait points will be replaced by wax blocks in preparation for the next monitoring phase of the project and these will be checked monthly for up to two years for signs of rodent activity.

All being well, the number of bait points will be reduced this spring, though points around harbours and other key areas around the Calf and Kitterland will be left in place for monitoring purposes.

Strict precautions will be in place to avoid re-introduction of rodents from boat holds or cargo deliveries and there is an emergency action plan in case any longtails are detected after the eradication operation.

A very important element in the project planning is the avoidance of harm to wildlife other than longtails.

The likelihood of birds of prey eating poisoned longtails is minimised by the design of the bait stations and the tendency of affected longtails to make for their burrows and die out of sight.

However, a mysterious upsurge in bait-take in December appears to have been the work of clever crows pulling out the guard wires across the ends of the bait point pipes, prompting adjustments to the wires to make them more secure.

Fortunately, birds are less susceptible to the rodenticide than mammals and we hope that not too much damage was done before remedial action was taken.

It’s early days yet, but I think I can safely say that this project has succeeded in demonstrating what can be achieved if people work together in a common interest.

If we remain vigilant and manage to keep longtails off the Calf, we can look forward to seeing increasing numbers of Manx shearwaters and other seabirds on the island and around the south west coast, with knock-on benefits for resident wildlife watchers and visitors to the Isle of Man.




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