Rare red ants get a helping hand


Jan 25, 2007

Red-barbed ants have not been bred in captivity before

Conservationists have been awarded almost £50,000 to help save a rare species of red ant from becoming extinct in mainland Britain.

Red-barbed ants have declined as a result of a loss of habitat, and are now only found at one site in Surrey.

A team, led by the Zoological Society of London (ZSL), plans to captive breed the species at London Zoo before releasing them into the wild next year.

The project has been funded by a National Heritage Lottery grant.

The ant (Formica rufibarbis), described as one of the UK's rarest native species, is restricted to one colony in Surrey and a few sites on the Isles of Scilly, 28 miles (45km) off the coast of Cornwall.

"The ants are quite unusual because they form nests that are either all female or all male," said Emily Brennan, ZSL's native species conservation programme manager.

"We have only got one nest left in Surrey, and that nest is only producing females," she told BBC News.

"So it is going to become extinct on mainland Britain, unless we re-introduce a number of new nests, some of which must be male nests."

She described the captive breeding programme, based at London Zoo, as a trip into the unknown.

"It seems as if the ants have quite a complicated lifecycle; they use pheromones but we do not know what these pheromones are yet, so we want to try to isolate these in our research facilities.

"This will be really interesting because no-one has been able to get them to reproduce in captivity before."

Scientists will take females from the nest in Surrey, and males from colonies found on the Isles of Scilly.

Invasion threat

Mrs Brennan said the main reason behind the ants' demise was the loss of suitable heathland habitat.

"They needed warm areas and many of the heathlands had short heather and bare ground. But for many years, they became overgrown and too cold for the species," Mrs Brennan explained.

However, she said that there had been a lot of recent work to restore the areas to favourable conditions.

Another threat facing the nests, surprisingly, comes from another species of ant.

"They can be invaded by a species called slave-maker ants, which seem to be spreading quite rapidly across the UK," she reveals.

"What they do is take all the pupae, carry it off to their own nest and bring them up as slave-maker ants - this is what happened at one site in Surrey.

"So at the sites we are going to be working on, we are going to be making sure these ants are not in the area."

The project, which also involves Natural England and two Wildlife Trusts, will use volunteers to monitor and manage the selected sites.

Researchers aim to re-introduce at least 40 captive-bred nests each year, beginning next year, until the ants are well enough established to fend for themselves.