Interspecific differences in response to novel landmarks in bumblebees (Bombus sp.)

We provide evidence for interspecific differences in the behaviour of bumblebees which suggests that there may be important differences in the way that they navigate. Bumblebees commonly investigate the novel landmark presented by a human standing in open countryside. When doing so they perform a characteristic flight similar to that observed when a naïve bee first leaves the nest, suggesting that they are memorising the location of an unfamiliar landmark. We compare the frequency with which different bee species perform this behaviour. Striking patterns emerge. Only workers of certain bumblebee species were recorded investigating novel human landmarks, notably Bombus lapidarius and B. soroeensis. Other species such as B. pascuorum, B. hortorum and B. pratorum never performed this behaviour, yet were abundant in the study area. We suggest that this behaviour may be indicative of species with long foraging ranges and therefore greater need to pay attention to landmarks.