The Isles of Scilly are home to the rarest ant in Britain - the red-barbed ant, Formica rufibarbis. The red-barbed ant gets its name from red dorsal hairs found on its thorax although locally it is known as the St. Martin's ant, as this is its stronghold.
The red-barbed ant displays distinctive reproductive behaviour. During courtship, young winged females climb to the top of a blade of grass or plant stem to attract the attention of males by scent. After mating, the new queens try to establish a new colony. The queens mate only once in their lifetime and store sperm inside their bodies to fertilize eggs for the rest of their life.
The red-barbed ant excavates its nests in the ground or under stones. Each nest may contain a colony of workers with one or more queens and a brood. The queens are found in the bottom of the nest up to 30cm below ground and are protected by worker ants that attack any intruders such as other ant species and insects.
The red-barbed ant is one of the most endangered species in the UK. It was first discovered in 1896 and has always been considered rare but due to the loss of suitable habitat, their populations are currently declining.
The red-barbed ant is particularly fussy about where it lives, liking heathland with bare patches of ground with short vegetation so that it can get sufficient warmth from the sun. Many of these British heathland habitats are also threatened by development or overgrown due to a lack of grazing and other suitable management.
Whilst the red-barbed ant in Scilly is secure and flourishing, on the Mainland it is found to be struggling and close to extinction, with only one remaining nest where all the winged reproductive ants that swarm out in the early summer are found to be the same sex, making reproduction impossible. A rescue operation has been set up to save the red-barbed ant on mainland Britain. It is Funded by the Heritage Lottery Fund with partners Zoological Society of London (ZSL), Isles of Scilly Wildlife Trust, Surrey Wildlife Trust, and ant experts.
In June 2007, the ZSL came to the island of St. Martin's to carry out a thorough survey of the ants and to collect some mated females, for captive rearing. As you can imagine, finding mated queen ants on a huge area of heathland is rather like finding a needle in a haystack! None the less the expedition found over 40 red-barbed ant nests located on Chapel Down, St. Martin's. A previous total number of nests found on Chapel Down was 11, and other nests were found on several of the Eastern Isles.
ZSL took 34 queens for the captive rearing programme; they were safely transported back to London Zoo and are now happily laying eggs in their new home, a specially designed breeding and quarantine facility. Ants will be reared in captivity and stringent health screening will be carried out prior to releasing captive reared colonies into the wild in order to minimise the risk of transfer of exotic pathogens. Further expeditions to Scilly will take place in 2008 and 2009.
The breeding programme aims to rear red-barbed ants in captivity at London Zoo for release in the wild, and the project will also manage the habitat at existing red-barbed ant sites in Surrey and create suitable habitats at other nearby sites where the ant has been found in the past but lost due to lack of appropriate management. Relatively small areas of land can support a high density of nests.
The existing wild population in Surrey where there is only one remaining nest, will be supplemented with captive-reared stock and reintroductions will be made with the aim of establishing resident breeding populations in that area.
The project aims to reintroduce at least 40 captive-reared nests into the wild annually for the duration of the project. The first introductions will be made in the summers of 2008 and 2009. Volunteer's assist with captive rearing, recording and monitoring red-barbed ants and nests in the wild and habitat management.
Article courtesy Isles of Scilly Wildlife Trust.
Tags: Formica | Rufibarbis | Conservation
What is AntBlog?
We're hobby Myrmecologists blogging captive colony development and promoting insect conservation... more
Featured Content
What's new?
Ant Community Ecology in Bird's Nest Ferns
Tropical rainforests are hot...
Ant mimicry - myrmecomorphy
Many species of ants form sy...
Formica rufibarbis
The Isles of Scilly are home...
Lasius niger
Lasius niger, the black gard...
Camponotus Ligniperda
Camponotus Ligniperda are Eu...
Pheidole pallidula
Pheidole pallidula is a spec...