Incorporation of cigarette butts into nests reduces nest ectoparasite load in urban birds: new ingredients for an old recipe?
+ Author Affiliations
- e-mail: isalorull@gmail.com
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.
