Unusual nectar-thieving behavior in Brazil

Abstract

When an animal is observed visiting a flower, we tend to think of it as a mutualistic interaction, in which both participants benefit to some degree. However, not all such interactions are mutualisms, as in instances where one partner (the animal) benefits at the expense of the other partner (the plant). In pollination ecology, the lopsided beneficiaries of interactions like these are called nectar “robbers” or “thieves”. This seems to be the case for the bananaquit (Coereba flaveola), a member of the tanager family, seen here in a backyard in the city of Campinas, São Paulo, Brazil, consuming nectar from immature non-native Ixora flowers. Although bananaquits occasionally pierce mature flowers from the side to rob nectar (Sci Rep 2022; doi.org/10.1038/s41598-022-16237-9), the bird pictured here is mechanically opening a closed immature flower with its beak to access the nectar. Does the premature opening of a flower affect its development and the plant's reproductive success? Here, the bananaquit could be considered a nectar thief because of the temporal mismatch, given that the flower's pollen is unavailable or nonviable. Has this behavior spread through the local population of bananaquits, and how did it emerge? Is it a learned behavior by the bananaquit having observed a conspecific or else a different species? Is it a spontaneous behavior that arose independently in certain individuals? Physically opening an immature flower might represent a previously undocumented form of thieving. Further investigations are necessary to determine the relative gains and losses associated with this type of animal–plant interaction.