Effect of nestbox construction and colour on the occupancy and breeding success of nesting tits Parus spp.

Abstract

Capsule Breeding performance was not affected, although variation in nestbox occupancy may result from perceived differences in protection from predators and insulation properties.
Aim To assess if nestboxes of different construction and colour were occupied differently by breeding tits and affected breeding success.
Methods A total of 292 nestboxes of different construction and colour were placed in a range of habitats and their occupancy, and the clutch size, brood size and number of young fledged of the birds that used them were measured.
Results Overall 272 tit nests were included in the analysis. Although there were species-related differences in the occupancy of the different types of nestboxes, more tits nested in the boxes constructed from woodcrete (64% of nests) compared to the wooden boxes (36%). More tits nested in green (72%) rather than brown boxes (28%) and in boxes with entrance holes (68%) rather than wedges (32%). The clutch size, brood size and number of young fledged did not vary in relation to nestbox type.
Conclusion Within the parameters of the experimental design of this study, tits are more likely to nest in woodcrete boxes than in wooden boxes, and in wooden boxes that are green and have holes rather than brown boxes with wedge entrances. It is likely that the smaller internal volume, internal darkness, insulating properties and perceived protection from predation were the reasons for these differences.