We worked with Green&Blue to look at if bees preferred to use different colour Bee Bricks, or if they preferred bricks placed at different heights. Chris and Rachel, two MSc students at the University of Exeter, placed coloured Bee Bricks out in gardens across Cornwall. A cool, wet spring meant that the bees didn't get going as quickly as we'd like so we didn't get large numbers of bees nesting in the bricks. There were definitely bees nesting though, mainly mason bees (Osmia spp.), but also some leaf cutter bees (Megachile spp). The most striking result we found was that bees really don't like nesting in bricks placed on the ground!
Chris and Rachel installing a Bee Brick structure testing whether the height of the brick affects the number of bees nesting in the brick.
Chris and Rachel also surveyed solitary bees in the areas surrounding the sites where the bees were nesting. They didn't see many cavity nesting bees (the ones likely to use the bricks) in either standard household gardens or bigger public gardens. The cavity nesting bees they did see were foraging on native and introduced garden plants, but more were seen on native flowers. Based on this evidence we know we can help bees by providing nesting areas and a range of native flowers for them to forage on. We will be continuing this study into whether bees have a preference for colour bricks by going back next year to see how many of the nesting bees emerge, and whether more bees use the bricks in the second year they are out.
Photos © Ros Shaw Post written by: Dr Rosalind Shaw Associate Research Fellow Environment & Sustainability Institute University of Exeter