Last year was not a good year for bumblebees, according to the Bumblebee Conservation Trust.  The trust has been collecting data on bumblebee numbers since 2008, through the BeeWalk.  The BeeWalk project began as as a small scale initiative at Weybourne, Norfolk.  This involved counting the bumblebees seen on a monthly walk along a set route from March to October.  The BeeWalk was opened up first to members of the BCT and then to the wider public - a citizen science project.  

Today, it is the Trust’s longest running (and largest) project.  For each site in the BeeWalk scheme, the bumblebee species seen are recorded, and whether the bee is a queen, worker or male.  Also recorded is information about the site (habitat type, land use, temperature and other relevant information).  The fact that the BeeWalk has been running for some years and is now widespread (across England, Wales and Scotland) means that it is possible to monitor how bumblebee populations are changing and correlate with any changes in climate and land use.

In March last year, bumblebee numbers were relatively OK, having emerged from winter dormancy into warm and sunny conditions. Queen bumblebees need stable weather to establish their colonies.  In April the weather turned wet and cold but numbers remained stable.  But in June, the weather was particularly ‘unseasonable’ and worker bees of many  species were noticeably absent from many counts.  The effect was especially true of those species that normally reach peak numbers in early summer.  White tailed and red tailed bees were down by 60% and 74% respectively. In contrast, the garden bumblebee (Bombus hortorum) showed a smaller decline of just 12%.

In July and August, the weather improved as did numbers but across the country overall bumblebee numbers (for all species) were down by 22%.  The red tailed bumblebee has declined year on year since 2015, but last year was the worst.  On a more positive note, some of the rarer species (the shrill carder & brown banded carder) have shown year on year increase.

The decline highlights the sensitivity of pollinators to changing weather patterns, and emphasises the need for conservation efforts through:

• Protecting natural environments
• Restoring wild flower meadows
• The use of sustainable land management practices eg avoidance of insecticides (such as the neonicotinoids)
• Improving habitat connectivity to support bumblebee  movement and survival