One of Northern Ireland's rarest bees has been discovered crawling around in dried-up vegetation at the north coast beach of White Park Bay.
The northern colletes bee (Colletes floralis) was thought to have vanished from Northern Ireland – until 2003, when it was found by the RSPB at four sites along the north coast.
Now a number of individuals have been discovered at White Park Bay by volunteer butterfly surveyor Patrick Barton, who was scouring the grasslands for butterflies when something else caught his attention.
Except for the occasional flicker of translucent wings, the bees' striped abdomens and fuzzy fox-coloured thoraxes were barely visible as they burrowed around on the sand amid the dried up vegetation.
"I was thrilled to see the bees. I knew something about them was different," Patrick said. "I had seen similar in the far north of Scotland on a family holiday years ago."
The insects, now confirmed to be northern colletes bees, are classified as rare and actively breed from mid-June to late August in coastal habitat such as White Park Bay.
Solitary female bees make burrows in sandy soil before getting to work laying eggs in chambers within the burrows. They will usually nest closely together at the same site but they are not social insects and act individually.
As much as 50% of the European population of the northern colletes bee is concentrated in the UK – specifically the north coast of Northern Ireland and the Scottish western isles.
At a time when bee populations are said to be in decline, sightings such as that of the northern colletes at White Park Bay are valuable as in indication of the health of local ecosystems, the National Trust said.
Giant's Causeway conservation expert Dr Cliff Henry said he hoped the increase in sightings was a sign their decline is slowing.
"There are 101 recorded species of bee in Ireland, and unfortunately 42 of these are in decline," he said.
"At White Park Bay the National Trust takes great effort to maintain the habitat in suitable condition for the bee. The level of cattle grazing is closely monitored and large areas of bramble, blackthorn and bracken have been cleared in recent years to preserve the flower-rich grassland that the bees depend on."
The northern colletes bee hadn't been sighted in Northern Ireland since 1933. But after a hiatus of 70 years, it was rediscovered at four sites on the north coast during an RSPB survey.
It is believed once to have been more widespread in Ulster, but changes in land use over the last century have reduced and fragmented its preferred habitat – flower-rich dune grasslands.
The bee is now only known from the sites on Northern Ireland's north coast, north and west Scotland with strongholds in the Scottish western Isles and several coastal areas of the Irish Republic.
Northern colletes bee:
Appearance: Medium-sized, slender bee. The abdomen is black with a narrow white band on each segment. The upper side of the thorax and the face are covered in fox-coloured hairs.
Habit: A solitary bee, meaning that a single female constructs and provisions a nest. The only bee species which is more widespread in Ireland than Britain.
Nesting: Nest aggregations have been found in gently sloping or flat ground in dry dune slacks. These can be identified by the presence of holes, which in suitable weather will have adults flying in and out.