Wood Warbler Phylloscopus sibilatrix


Justification of Red List Category
This species has an extremely large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (extent of occurrence <20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). Despite the fact that the population trend appears to be decreasing, the decline is not believed to be sufficiently rapid to approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size is extremely large, and hence does not approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern.

Population justification
In Europe, the breeding population is estimated to number 7,060,000-11,100,000 pairs, which equates to 14,100,000-22,100,000 mature individuals (BirdLife International 2015). Europe forms c.80% of the global range, so a very preliminary estimate of the global population size is 17,600,000-27,600,000 mature individuals, although further validation of this estimate is needed.

Trend justification
In Europe, trends between 1980 and 2013 show that populations have undergone a moderate decline (EBCC 2015).

Distribution and population


This species breeds in lowlands, in moist and shady deciduous woods, typically beech (Fagus), mixed oak (Quercus), hornbeam (Carpinus) and sweet chestnut (Castanea), with closed canopy and sparse undergrowth. It is also found in mixed stands of spruce (Picea), alder (Alnus), birch (Betula), pine (Pinus) or occasionally ash (Fraxinus).The optimal breeding areas are mixed stands with trees of mixed ages spaced well apart. In its African non-breeding grounds it uses humid evergreen forest, moist thickets, forest edge, dry woodland and forested mountain slopes as well as wooded savanna and scattered trees in forest clearings, often in fig trees (Ficus), occasionally in mangroves. It breeds from May to July and normally lays five to seven eggs. The female chooses the nest site and builds the nest which is a ball of dry grasses, leaves, plant stems and fibres, bark strips and animal hair. It is usually built on the ground but occasionally found under a fallen tree or roots (Clement 2015). The diet is mainly insects and other invertebrates, with some fruit taken in the autumn. The species is migratory and winters in sub-Saharan Africa (Snow and Perrins 1998).


In some areas changing forestry management practices have caused declines in this species (Mallord et al. 2012).

Conservation actions

Conservation Actions Underway
CMS Appendix II. Bern Convention Appendix II. There are currently no known conservation measures for this species.

Conservation Actions Proposed

Habitat quality should be restored through appropriate management, including the introduction of a moderate grazing regime (Mallord et al. 2012).


Text account compilers
Ekstrom, J., Butchart, S., Symes, A., Ashpole, J

Recommended citation
BirdLife International (2021) Species factsheet: Phylloscopus sibilatrix. Downloaded from on 22/09/2021. Recommended citation for factsheets for more than one species: BirdLife International (2021) IUCN Red List for birds. Downloaded from on 22/09/2021.