LC
Barred Warbler Curruca nisoria



Justification

Justification of Red List category
This species has a very 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 increasing, 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 1,150,000-2,110,000 mature individuals, with 579,000-1,060,000 breeding pairs (BirdLife International 2021), and comprises approximately 50% of the species' global range, so a very preliminary estimate of the global population size is between 2,300,000-4,220,000 mature individuals, although further validation of this estimate is desirable. The species' population in Europe is considered to have undergone a suspected increase over three generations (10 years) (BirdLife International 2021). As this region holds around half of the species' global range, the global population size is considered to be increasing over three generations.

Trend justification
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Ecology

This is a forest species but can occur in open woodland with a variety of structured vegetation: woodland margins, dense thorny bushes, clearings with rich undergrowth, isolated tree stands, young plantations, riverine thickets, hedgerows at railsides and roadsides, pastures, meadows, parks and orchards. Breeding occurs from May to July. The nest is an open elaborate cup-shaped structure coated externally with spider webs and the silk of caterpillar cocoons. It is usually hidden in dense thorny bush such as Rubus, rose (Rosa) or hawthorn (Crataegus), occasionally in juniper (Juniperus), c. 30–200 cm above ground. Clutches are three to six eggs. The diet is mainly made up of insects during the breeding season but fruits become steadily more important once breeding has finished and just before and during migration. The species is migratory, wintering in east Africa (Aymí et al. 2015).

Threats

In eastern Germany, the intensification of agriculture, ploughing of grassland and disappearance of large areas of low-intensity pastures and unproductive grassland have driven habitat loss. Population and range fluctuations may have climatic causes, as the species does not tolerate damp, cool, early-summer weather. The disappearance of Lanius collurio may have also caused declines through the interdependence of both species (Hagemeijer and Blair 1997).

Conservation actions

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

Conservation Actions Proposed
Habitat management for this species should include extensive grazing as this keeps vegetation varied and well structured and thus suitable for this species (Aymí et al. 2015).

Acknowledgements

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


Recommended citation
BirdLife International (2024) Species factsheet: Barred Warbler Curruca nisoria. Downloaded from https://datazone.birdlife.org/species/factsheet/barred-warbler-curruca-nisoria on 22/11/2024.
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 22/11/2024.