Greenish Warbler Phylloscopus trochiloides


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). The population trend appears to be increasing, and hence the species does not 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 14,400,000-19,700,000 pairs, which equates to 28,900,000-39,400,000 mature individuals (BirdLife International 2015).

Trend justification
The population is suspected to be increasing owing to a continuing westwards range expansion. The European population is estimated to be stable (BirdLife International 2015).


This species breeds in lowland and montane mixed birch (Betula) and conifer forests, also in broadleaf woods of beech (Fagus), maple (Acer) and lime (Tilia) interspersed with birch and pine (Pinus). It is also found in parks, gardens, riverine thickets and swamp-woodland with willows (Salix) and poplars (Populus). In central Asia it is also found in mixed taiga forests of fir (Abies), in the north-west Himalayas it is mainly found in oak (Quercus) forests, also juniper (Juniperus) and birch subalpine meadows with rhododendrons (Rhododendron) and in dwarf junipers or willows. In the north of the range it breeds in birch clumps and shrubs. The breeding season is from May to mid-August (Clement 2006). The nest is a large, domed structure with a side entrance and is made from grasses, plant fibres, moss, rootlets and leaves and is lined with finer material such as hair, fur, down and feathers. It is sited on the ground in tall vegetation or low scrub, under stones, windfall or tree roots and sometimes in a crevice in a bank, old wall or tree stump. Clutches are three to seven eggs (Snow and Perrins 1998). The diet is mostly small invertebrates but also takes fruits of elder (Sambucus) and some seeds. The species is migratory (Clement 2015).


There are not thought to be any current significant threats to this species within its European range.

Conservation actions

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

Conservation Actions Proposed
No conservation measures are currently needed for this species within its European range.


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

Recommended citation
BirdLife International (2022) Species factsheet: Phylloscopus trochiloides. Downloaded from on 03/07/2022. Recommended citation for factsheets for more than one species: BirdLife International (2022) IUCN Red List for birds. Downloaded from on 03/07/2022.