What is nectar robbing?
AThe ancient relationship between flowering plants and pollinators is based on cooperation: one is given help with reproduction, while the other earns a high-energy meal. Delve deeper, though, and it becomes clear that this is a complicated relationship.
Flowers use an astounding array of shapes, colours and scents to entice their preferred pollen porters; for example, deep, tubular flowers are accessible to only the longest tongues. However, many shorttongued bees have learned to sidestep this inconvenient anatomy. These resourceful foragers bite holes through the corolla to gain access to nectaries.
Flowers such as comfrey, aquilegia and honeysuckle commonly bear the mark of a thief. Buff-tailed and red-tailed bumblebees are known to pilfer, and can learn this behaviour from one another; other bees are not averse to using the holes created by these thieves.
Interestingly, research shows that nectar robbers don’t necessarily have a negative effect on a plant’s ability to set seed, and many bee species combine theft with honest foraging.
Having chewed a hole in the base of a comfrey flower with its mandibles, a bumblebee extends its tongue into the corolla to ‘rob’ nectar.