LC
Common Chiffchaff Phylloscopus collybita



Justification

Justification of Red List category
This species has an extremely large range and the population size is extremely large, hence does not approach threatened thresholds for the range or population size criteria. The population trend appears to be stable, and hence the species does not approach the thresholds for Vulnerable under the population trend criterion. For these reasons the species is evaluated as Least Concern.

Population justification
In Europe, the total population size is estimated at 72,100,000-114,000,000 mature individuals, with 36,000,000-56,700,000 breeding pairs (BirdLife International 2021), and comprises approximately 95% of the species' global range, so a very preliminary estimate of the global population size is between 75,900,000-120,000,000 mature individuals, although further validation of this estimate is desirable. The species' population in Europe is considered to have remained relatively stable over three generations (10 years) (BirdLife International 2021). As this region holds the vast majority of the species' global range, the global population size is considered to be stable over three generations.

Trend justification
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Ecology

The species occupies lowland deciduous forest and woodland with low undergrowth, as well as parks, hedgerows, shelterbelts, overgrown cemeteries, large gardens and reedbeds. In the east of its range it is found in spruce Picea and pine Pinus forests of Siberian taiga. Frequently, it inhabits damp alder Alnus and willow Salix woodland and river valleys and in the south of its range it prefers habitats with at least some tall trees but, exceptionally, breeds in coastal scrub lacking tall trees. It breeds from April until early August and lays five to six eggs. The nest is a ball of dry grasses, leaves, moss, plant fibres and feathers, normally placed on the ground and well concealed in a bramble bush Rubus fruticosus, a patch of nettles Urtica, grass or other thick vegetation. The diet is mostly insects and their eggs and larvae but also includes other arthropods, small molluscs Gastropoda, seeds and berries (Clement 2015). Most populations of the species are migratory (Snow and Perrins 1998).

Threats

Fluctuations in the British population are believed to be likely due to droughts in the non-breeding quarters in the West African Sahel (Clement 2015). In Finland, the species suffers from habitat fragmentation, interspecific competition from Willow Warbler P. trochilus and Goldcrest Regulus regulus, and climate change (Lampila et al. 2009).

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
Although this species is not threatened locally it may benefit from protection and restoration of its habitat. Monitoring should be implemented to detect population changes.

Acknowledgements

Text account compilers
Rutherford, C.A., Martin, R.


Recommended citation
BirdLife International (2024) Species factsheet: Common Chiffchaff Phylloscopus collybita. Downloaded from https://datazone.birdlife.org/species/factsheet/common-chiffchaff-phylloscopus-collybita on 22/12/2024.
Recommended citation for factsheets for more than one species: BirdLife International (2024) IUCN Red List for birds. Downloaded from https://datazone.birdlife.org/species/search on 22/12/2024.