Moss carder bees of Cornwall

Credit: Moss carder bumblebee (Bombus muscorum) by Emma Smith

Once widespread in the UK, the Moss carder bumblebee is in now in decline and found mostly in small, fragmented populations. Two key sites on Cornwall’s north coast, Penhale and Gwithian & Upton Towans, have been identified to better understand why this species is declining in the south of England.

The Moss carder bumblebee typically forages closer to its nest than do most other species, meaning that each nest only covers a small area, which must provide all the nests’ food needs. Therefore habitat loss and fragmentation are likely to have a disproportionately larger important effect, causing declines. Climate change, leading to warmer summers, is also a potential threat to this bumblebee, which is associated with cooler, wetter areas, and still thrives in northern Scotland. Unlike other declining bumblebee species, such as the Brown-banded carder bumblebee (Bombus humilis) it has not responded to habitat management interventions and continues to decline.

This project aims to increase our understanding of the bumblebee’s ecology, abundance and distribution at its Cornish sites. We will be recording the distribution of individual bumblebees, their forage preferences and inhabited habitats; this knowledge will inform our conservation practices and hopefully help to reverse the Moss carder bumblebee’s decline.

In addition, we aim to raise awareness about rare bumblebees in the project area and to increase data collection by volunteers in Cornwall, including establishing a new BeeWalk transect.