Data from: Comparison of the reproductive biology of hole-nesting passerines breeding in oak and spruce forest on Velký Kosíř hill nearby Prostějov

Avian breeding densities are often considered to be suitable proxies of
habitat quality. However, this simple method to estimation of habitat
quality has some shortcomings. Better than simply relying on breeding
densities it is to consider also survival and reproductive success of
birds inhabiting respective habitats. Here we compared the proportion of
occupied nest-boxes and reproductive success of birds between two
contrasting environments – deciduous (Quercus petraea) and coniferous
(Picea abies) forests. Proportion of occupied nest-boxes was larger in the
oak forest. Here also the two most frequent breeders, the great tit (Parus
major) and the collared flycatcher (Ficedula albicollis), started to breed
earlier in the season. The great tit had also larger clutches and breeding
success in the oak forest. However, they laid second clutches more
frequently in the spruce forest. This study offers only weak conclusions
about quality of the two habitats. Further studies would benefit from
space replicates and long-term monitoring of both adult and offspring
survival.