Kittiwake Population On St Martin’s Has Collapsed

There has been a collapse in the kittiwake population on St Martin’s.

That’s the conclusion of ornithologists who have been studying the birds for years across Scilly.

Dr Vik Heaney, who works with the Wildlife Trust and RSPB on the islands, surveying bird populations, says there has been a 40% decline in the population since 2000.

This year, around 70 pairs tried to breed in the area around the daymark on St Martin’s, with most laying eggs, but she says their recent counts have shown the number of chicks are down to half their initial level and these are very small for their age.

Vik says the causes are complex, but the most likely culprit is a decline in their food supply, sand eels. She says the parents are having to fly further to find these, leaving the chicks open to predation by gulls, crows and rats.

The sand eel levels have declined due to more variable levels of their food source plankton, most likely because of global warming, says Vik. She says there are fewer eels and they’re in deeper waters.

There is an ongoing project to rid the off-islands of rats and this could help more chicks survive, says Vik, but it still won’t solve the food supply problem.

There is ongoing work to electronically tag the birds to find out where they’re feeding.

Vik thinks the decline is, “absolutely devastating.”

She said kittiwakes are beautiful little gulls with an amazing call and finding their usual breeding grounds silent is very upsetting.

But there may be some good news. A small colony on St Agnes, near the Turk’s Head looks as though it’s faring better than the one on St Martin’s, although Vik says it’s too early to tell if those chicks will survive the next few weeks.