Plea to gardeners: keep a little patch unclipped to help save bumblebees
from the guardian
Let the neighbours mutter in dismay. Unruly, overgrown gardens have been highlighted as a vital refuge for the nation's dwindling bumblebee population, in a countrywide survey by conservationists.
Patches of garden that are left to run wild have been ranked as one of the richest for nesting bumblebees, offering better shelter and food resources than farmland and wooded areas, the report finds.
More than 700 volunteers took part in the National Bumblebee Nest Survey, with each scouring a garden and at least one other natural habitat to help with the understanding of the insects' favoured nesting sites.
Britain has about 25 native species of bumblebee, although three have been declared nationally extinct. Populations of nine other species are so precarious they have, or are due to be, designated special concerns by the government's Biodiversity Action Plan. In total, 15 species have seen serious contractions in their numbers, a drop that has alarmed conservationists.
The survey, published today in the Journal of Applied Ecology, found that gardens had among the highest densities of bumblebee nests, with an average of 36 nests per hectare.
Farmland fencing was also identified as a rich habitat for the insects, with 37.2 nests per hectare. Other countryside habitats made less suitable nesting grounds, with hedgerows being home to about 30 nests an hectare and woodlands just 11 nests an hectare.
Bumblebees build nests above ground or just beneath and line them with moss and leaves. Slightly neglected gardens are particularly good habitats for the bees because of the abundance of nesting options, such as compost heaps and bird boxes, and additionally the rich variety of flowers over the year that many gardeners cultivate.
"These kinds of gardens really provide a refuge for bumblebees, as long as people don't manage them too carefully," said Juliet Osborne, an ecologist at Rothamsted Research, the agricultural research centre based at Harpenden, Hertfordshire. "If you've got different grass areas, flower beds, compost heaps and hedges, there's a vast variety of habitats for bumblebees," she said.