Bilberry bumblebee

How to recognise it

A small to medium bumblebee with a yellow collar and a second yellow band, and a vivid orange-red tail extending over more than half the abdomen — a far larger red area than the red-tailed bumblebee shows.

• Orange-red covering more than half the abdomen, which no other British bumblebee shows.
• Two yellow bands on a black body.
• Upland: moor, mountain and northern heath, on bilberry.
• Flies April to August at altitude.

Body length 10–17 mm (typically 13 mm).

Biology

Social organisation

Eusocial, colony dies each autumn

A true colony with a queen and workers, but only for one season: everyone dies in autumn except mated new queens, who overwinter alone. Bumblebees.

Colony size at peak

30–120 individuals

Colony lifespan

One short upland season.

Winter

Mated new queens overwinter alone in the ground.

Castes

Queen, Workers, Males, New queens

Nesting

Burrows in the ground

Nests underground, often in old rodent burrows under heather and bilberry, on moorland and mountain slopes.

Carries pollen

Corbicula (pollen basket) on the hind leg

On the wing

April to August

Lifecycle

1. 1EmergenceQueens emerge in April, timed to bilberry flowering.April to May.
2. 2Short seasonA compressed colony cycle to fit an upland summer.
3. 3ReproductionReproductives from July.

Where it lives and what it does

Habitat

Upland moor, mountain, northern heath and open woodland with abundant bilberry.

Distribution

Northern and upland Europe. In Britain, largely confined to northern and western uplands — the Pennines, Wales, the Lake District and Scotland.

Behaviour

Closely associated with bilberry, which it works heavily in spring, moving onto heather and legumes later. Its retreat to higher ground is consistent with a warming climate compressing suitable range upwards, and it is monitored as an indicator for that.

Pollination role

A significant pollinator of bilberry, and therefore of an upland fruit crop that matters to birds, mammals and — in Fennoscandia — to people.

High on bilberry and upland heath flora, where alternatives are scarce.

What it forages on

Bilberry above all in spring, then heather, legumes and thistles.

Honey

Keeps only a few days of stores

A few days' worth in wax pots.

Relationship with people

How people interact with it

A moorland species most people meet only while walking. Its uphill retreat makes it one of the more frequently cited British examples of a climate-driven range shift.

Conservation

Declining at the southern and lower edges of its range. Upland habitat change, overgrazing that removes bilberry, and warming are all implicated.