Ynghylch

As the name suggests, bilberry bumblebees are fond of feeding on the flowers of bilberry plants. These make up a very important part of the diet of queens in spring, though they may also visit sallow blossoms. Worker bees are less picky and forage on a range of flowers including heathers, bird's-foot trefoil, and clovers.

They're sometimes known as mountain bumblebees, as they're usually found in mountain or upland habitats. They like a mosaic of habitats that includes flower-rich grasslands as well as areas of heath. Queens emerge from hibernation in April to look for a nest site. They'll often nest underground in old mammal burrows. Once she's found a suitable site, the queen insulates it with dry materials such as grass, stores some pollen and nectar for the larvae to feed on, and lays her eggs.

The first bees to hatch are female worker bumblebees. The workers help the queen raise the next brood and take over the pollen and nectar collecting duties. In late summer, the queen starts to lay eggs that produce male bees and new queens instead. Once new queens have mated, they spend late summer and early autumn fattening up on pollen and nectar, preparing to spend the winter tucked away in a sheltered spot - usually burrowed into loose soil. They'll emerge the following spring to make their own nest.

The bilberry bumblebee was once widespread across northern and western Britain, but the population has declined dramatically. This is thought to be a result of habitat loss. The bilberry bumblebee's dependence on high altitude habitats also makes it highly vulnerable to changes as a result of the climate crisis, especially as it appears to have a lower heat tolerance than bees found at lower altitudes.