title: Incorporation of cigarette butts into nests reduces nest ectoparasite load in urban birds: new ingredients for an old recipe?
abstract: Birds are known to respond to nest-dwelling parasites by altering behaviours. Some bird species, for example, bring fresh plants to the nest, which contain volatile compounds that repel parasites. There is evidence that some birds living in cities incorporate cigarette butts into their nests, but the effect (if any) of this behaviour remains unclear. Butts from smoked cigarettes retain substantial amounts of nicotine and other compounds that may also act as arthropod repellents. We provide the first evidence that smoked cigarette butts may function as a parasite repellent in urban bird nests. The amount of cellulose acetate from butts in nests of two widely distributed urban birds was negatively associated with the number of nest-dwelling parasites. Moreover, when parasites were attracted to heat traps containing smoked or non-smoked cigarette butts, fewer parasites reached the former, presumably due to the presence of nicotine. Because urbanization changes the abundance and type of resources upon which birds depend, including nesting materials and plants involved in self-medication, our results are consistent with the view that urbanization imposes new challenges on birds that are dealt with using adaptations evolved elsewhere.
authors.affiliation: Departamento de Ecología Evolutiva, Instituto de Ecología, Universidad Nacional Autónoma de México, México 4510, Mexico.
authors.forename: Monserrat
authors.initials: M
authors.lastname: Suárez-Rodríguez
authors.forename: Isabel
authors.initials: I
authors.lastname: López-Rull
authors.forename: Constantino Macías
authors.initials: CM
authors.lastname: Garcia
mesh_terms: D000818:Animals; D002482:Cellulose / Q000031:analogs & derivatives / Q000032:analysis / Q000494:pharmacology; D046369:Finches / Q000469:parasitology* / Q000502:physiology; D008800:Mexico; D008925:Mites / Q000502:physiology*; D009425:Nesting Behavior; D009538:Nicotine / Q000032:analysis / Q000494:pharmacology; D011157:Population Dynamics; D046370:Sparrows / Q000469:parasitology* / Q000502:physiology; D062789:Tobacco Products; D014507:Urbanization
chemical_list: C005062:acetylcellulose; D009538:Nicotine; D002482:Cellulose