Nest-switch and nest site selection pattern in the double-brooded Japanese tits (Parus minor)

Most studies on nest site selection in multiple-brooded birds indicate
that breeders tend to reuse the original nest site for subsequent breeding
attempts within the same season. However, there are also some instances
that many breeders may choose to move and build a new nest. The factors of
habitat affecting nest switching of multiple-brooded avian species are
poorly investigated. In this study, we investigated whether facultatively
double-brooded Japanese tits (Parus minor) adapt their nest site
characteristics in response to changes in environmental conditions during
the second breeding attempt. Our results showed that second breeding nest
boxes of Japanese tits had lower shrub height and fewer total number of
tree species, but taller nest box height and higher shrub density compared
to the control nest boxes. Compared with first-breeding nest boxes,
second-breeding nest boxes used by Japanese tits had lower shrub height
and higher shrub density. Our results suggested that Japanese tits
selected nest sites for second breeding based on nest site
characteristics, which may be related to food availability or predator
avoidance.