Habitat preferences and nest site selection by sympatric populations of Middle Spotted Woodpecker (Dendrocoptes medius) and Syrian Woodpecker (Dendrocopos syriacus) in natural mountain forests of Southwest Iran

Abstract

We examined habitat preferences and nesting requirements of sympatric populations of Middle Spotted Woodpecker (Dendrocoptes medius) and Syrian Woodpecker (Dendrocopos syriacus). We carried out our study in 2015–2018 in natural mountain forests of Southwest Iran. We compared selected features of nesting, territory, and outside territory tree stands of the studied woodpeckers. The Middle Spotted Woodpecker occupied only oak forests, but the Syrian Woodpecker inhabited heterogenic forests that included the preferred tree of this species, the Mount Atlas Mastic. We recorded that in the breeding territories of the Middle Spotted Woodpecker, a greater area covered by tree crowns, as well as a larger number of trees, and a larger trunk basal area were observed in comparison to the territories occupied by the more plastic Syrian Woodpecker. Different habitat preferences demonstrated by both species could be a result of the selection of tree stands that provide the necessary food resources for each woodpecker species. Adaptation of Syrian Woodpecker to use heterogenic forest stands including tree species that produce fruits and as Mount Atlas Mastic trees, which likely allowed this species to colonise in Asia and Europe non-forest tree stands as orchards or gardens. Our results showed that poor tree condition and large tree trunk dimensions had a positive impact on the selection of nesting sites by both species. The presence of trees with large trunk dimensions was associated with multiple years of use of woodpecker breeding sites in the studied forests. Maintaining habitats in suitable condition for both studied woodpeckers can be achieved by preserving natural forests in the mountain regions of Iran.