• Name: Red-barbed (St Martin's) ant | Formica rufibarbis
  • Size: Worker size: 4-8 mm | Queen size: 12 mm
  • Life span: Red barbed ant Workers may live 1-3 years | Queens can live for up to 14 years (10 years may be more usual)
  • Diet: Nectar and small invertebrates | they will milk Aphids for their honeydew
  • Reproduction: Queens mate only once during their lifetime; storing sperm inside their bodies to fertilize eggs for the rest of their life
  • When to see: Spring, Summer & Autumn (March to September)
  • Where to see: Heathland areas with bare patches of ground and short vegetation to enable warming from the sun (records of Scilly colonies on St Martin's, Tean, Great Ganilly & Nornour 
  • Conservation status: Red Data Book | Endangered (in Britain).
  • Population Trend: Decreasing (but doing well in Scilly)
  • Threats:  Loss of habitat, climate change (changes in weather patterns), predation or slave-making from other species. 
  • Fun Fact: The Red-barbed ant is considered one of the most endangered species in the UK being only found in Scilly and Chobham Common in Surrey

Description: The Red-barbed (St Martin's) ant gets its name from the distinct red colouration of its thorax (middle section) cause by tiny red hairs, which contrast with its black head and abdomen (bottom); it is the rarest ant in Britain!

The Red-barbed ant displays distinctive reproductive behaviour.  During courtship, young winged females climb to the top of a blade of grass or plat stem to attract the attention of males by scent.  After mating the new Queens try to establish a new colony.

The red-barbed ant requires successional heathland and dry, sun exposed habitat for nesting and foraging.

Suitable habitat involves bare ground, short grass and heather mosaics over loose or sandy soils within maritime heath and grassland; as found on St Martin's.  Nests are either excavated in the ground or under stones.

Whilst the Red-barbed ant in Scilly seems to be doing well, if not flourishing, on the Mainland it has been found to be struggling and close to extinction. 

In the early 2000's a project was initiated to collect mated females from Scilly for captive breeding and release into the wild, in Surrey, in an effort to establish additional resident breeding populations in that area. 

Want to know more?  You can find out more about the re-indtroduction of Red-barbed ants to Surrey from the 2008 Conserving the red-barbed ant (Formica rufibarbis) in the United Kingdom Report.   If you want to help us find out more regarding the distribution of this little Scilly speciality please report and record your sightings (with pictures) via the iRecord App. 


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With thanks to Ian Condon for the use of St Martin's Ant Image