Parental provisioning behaviour in Pied Flycatchers Ficedula hypoleuca is well adjusted to local conditions in a mosaic of deciduous and coniferous habitat.

摘要

Capsule: Pied Flycatchers are better able than Great Tits to adjust their feeding behaviour to varying conditions in the same area. Aims: Great Tits breeding in a mosaic of deciduous and coniferous forests in the northern temperate region exhibit consistently lower breeding success in their preferred deciduous habitat than in coniferous habitat. This was explained by the unexpectedly poor nestling feeding conditions in deciduous forests of this region. We studied whether the same paradox applies to Pied Flycatchers that occupy the same habitats in the same area. Methods: Parental provisioning behaviour was studied using video-recording and experimental manipulation. Caterpillar abundance and basic breeding parameters were measured in different habitat types. Results: Parental provisioning frequency and the proportion of caterpillars in nestling diet was lower, while food objects were on average larger, in coniferous compared with deciduous habitat. However, the total volume of caterpillars and adult Lepidoptera delivered to nestlings did not differ between habitats. In contrast to Great Tits, offspring body parameters in Pied Flycatchers did not differ between habitat types. Conclusions: These results demonstrate how the relative suitability of particular habitat types varies between species and is dependent upon geographical location.