Successful Urban Bumblebees

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Photo courtesy of Wikimedia Commons/Ivar Leidus
Bumblebees have adapted surprisingly well to life in urbanized environments.

Increased urbanization hasn’t been positive for most wildlife; however, one surprising species has managed to adapt to modern cityscapes. According to a recent study from The Royal Society, the independent scientific academy of the United Kingdom, buff-tailed bumblebee colonies (Bombus terrestris ssp. audax) have better reproductive success when located on urban land rather than agricultural land.

A research group spearheaded by Ash E. Samuelson conducted a 10-week study of 38 bee colonies placed across southeast England. The scientists used wild-caught queen bees to establish hives, which they then located in sites with various degrees of urbanization. The team closely tracked colony growth, reproductive output, nutritional stores, parasite prevalence, and colony lifespan. To their surprise, they found that bumblebee colonies in central London and suburban villages were larger and longer-lived, with higher rates of young with reproductive ability, larger food stores, and fewer brood parasites than those in rural, agricultural areas. The researchers report: “Our results show a link between urbanization and bumblebee colony reproductive success, supporting the theory that urban areas provide a refuge for pollinator populations in an otherwise barren agricultural landscape.” (Read the paper by searching for “bumblebee colony urban environments” on the Royal Society website.)

Farming practices that do little to benefit pollinators may explain these results. In agricultural areas, which tend to focus on monocultures, there’s much less plant diversity than can be found in cities. That dramatically reduces the amount of pollen and nectar that can be stored by a colony, and can even negatively impact the bees’ immune systems.

Exposure to below-lethal doses of pesticides affects bees’ foraging and feeding behaviors, as well as inhibits their reproduction. While city gardens certainly aren’t devoid of all pesticides, research has shown that bees in agricultural areas are exposed to higher pesticide concentrations at higher rates than their urban counterparts, which could be affecting the wild bee population.

What can we do to aid our pollinators? Help bees directly by planting a diverse range of pollinator-friendly flowers, such as lavender, hyssop, mint, hollyhocks, dahlias, sweet peas, and foxgloves. You can also support policies to limit the use of bee-harming pesticides in agriculture.

Mother Earth Gardener
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