Studies on Hole-Nesting Birds in Natural Nest Sites

Abstract

Hole-nesting birds in natural nest sites was studied and compared with those in nest-boxes. The study was performed in 1975-1977 in a wooded area north of Arnhem, Netherlands, where many roads are bordered with old deciduous trees, rich in tree holes. Conifers had few holes. The density of suitable holes was noted for different areas. Hole parameters and nest heights were measured to determine species' preferences. Interspecies competition and species composition were investigated. The territoriality of great tits was discussed. Other birds observed include the starling, pied flycatcher, blue tit, marsh tit and red start.