Habitat-specific variation in bacterial loads of wooden nest boxes in
the pre-breeding period
Abstract
Among environmental factors affecting life - history traits of birds
breeding in nest boxes, an influence of microbial communities is
relatively poorly understood. In this study, nest boxes used for
breeding by great tit (Parus major) and blue tit (Cyanistes caeruleus)
were sampled before the start of the breeding season to assess the
bacterial loads of the nest box. Samples from the entrance hole and the
interior of the nest box were taken at two different study sites: an
urban parkland and a natural forest. Nest boxes were sampled to check if
their bacterial loads differed between habitats. The second objective of
this study was to check whether the occupancy of the nest boxes during
the previous season would influence the bacterial load of the nest box.
To verify this prediction, two categories of nest boxes were sampled at
both study sites: nest boxes occupied by any of the two tit species in
the previous season for breeding and nest boxes that had remained empty
that year. The bacterial load of the nest box was significantly higher
in the forest study area in both the occupied and unoccupied nest boxes.
The nest boxes used for breeding in the previous season had
significantly higher bacterial loads, but only in the forest area. Our
results suggest that the bacterial load of the nest box can vary between
habitats and may be positively related to the presence of the nests in
the previous breeding season.