A Bad Habit for Birds?
Recent research suggests that urban birds might incorporate cigarette butts into their nests as a means of repelling insects and parasites. Nicotine is the tobacco plant’s natural defense against herbivores, but research suggests that birds might be using this defense mechanism to their advantage.
The study, summarized here by Scientific American, demonstrated that House Sparrow and House Finch nests containing filters from smoked cigarettes had fewer parasites than those without. However, the study does not address whether the chemicals in the filters also negatively affected the health of the chicks in the nest. Without this key piece of information, it’s difficult to know whether including cigarette filters in a nest provides a net advantage to urban birds. Although discarded cigarettes are not on our list of recommended nesting materials to provide for birds, it is interesting to consider that some birds might be deliberately feathering their nests with the unsavory litter.