Urban and rural chickadee response to novel object and simulated predator

Urbanization is changing natural landscapes worldwide, pushing species to
quickly acclimate or adapt if they are to survive in urban environments.
Mountain chickadees (Poecile gambeli) readily nest in both urban and rural
environments without suffering apparent reproductive costs. However,
whether urban-nesting chickadees are successful in these environments due
to differences in behaviour between urban and rural birds remains
untested. We examined the behavioural responses of urban and rural nesting
mountain chickadee females when presented with a novel object (red plastic
cup) or simulated predator (imitation squirrel model) at the nest.
Behavioural responses depended on both the type of model and the habitat.
As expected, mountain chickadees responded more strongly to squirrel
models than novel objects; however, the magnitude of the difference in
response depended on habitat. Urban birds seemingly ignored the novel
object, spending little time investigating, and re-entering the nest box
quickly. In contrast, rural birds spent more time reacting to the novel
object and alarm calling within 5 m of the nest. When presented with a
predator model, the urban birds reacted relatively more strongly (compared
to the novel stimulus) than rural birds, spending more time within 5 m of
the nest and alarm calling. These results suggest that either mountain
chickadees in urban environments quickly acclimatize to the presence of
novel objects or, potentially, that less neophobic birds
disproportionately settle in urban environments or experience positive
selection in urban areas. Either way, reduced neophobia may aid in
mountain chickadees’ ability to readily and successfully nest in such
habitats.