LC
Common Grasshopper-warbler Locustella naevia



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. 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. For these reasons the species is evaluated as Least Concern.

Population justification
In Europe, the total population size is estimated at 1,270,000-2,250,000 mature individuals, with 638,000-1,130,000 breeding pairs (BirdLife International 2021), and comprises approximately 70% of the species' global range, so a very preliminary estimate of the global population size is between 1,810,000-3,210,000 mature individuals, although further validation of this estimate is desirable. The species' population in Europe is considered to have undergone a small decline over three generations (10 years) (BirdLife International 2021). As this region holds the majority of the species' global range, the global population size is considered to be decreasing slowly over three generations.

Trend justification
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Ecology

This species breeds at the edges of open woodland, in damp grazing land, in rank grasses, beds of nettle (Urtica) and brambles (Rubus fruticosus), scrubby sedge or reed marshes, at field edges and on upland moorland with willow (Salix) and birch (Betula) scrub. Egg-laying occurs from late April to mid-July in western Europe and clutches are typically five to six eggs. The nest is a thick cup of grass, stems and leaves built on a base of dried leaves and lined with finer material, such as feathers or hair. It is usually placed on or near the ground in thick vegetation, often in a grass tussock, bramble or sedge. The diet is mostly insects but spiders (Araneae) and some small molluscs are also taken. The species is a long distance migrant, passing through the Iberian Peninsula to winter in West Africa (Pearson and Kirwan 2015). The obscurior race that breeds in the Caucasus probably winters in North-East Africa. The straminea race that breeds in Central Asia winters in southern Asia with large numbers spending the non-breeding season in India although some also migrate to North-East Africa. The mongolica race is presumed to winter in southern Asia (Pearson and Kirwan 2015).

Threats

This species suffers from changing land-use practices, such as the intensification of agriculture, leading to the destruction of grassland (Hagemeijer and Blair 1997), wetland drainage and scrub clearance (Hagemeijer and Blair 1997, Pearson and Kirwan 2015). The species is also likely to be affected by future climate change (Huntley et al. 2008).

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

This species would benefit from the preservation and promotion of low-intensity farming methods, which provide much suitable habitat (Hagemeijer and Blair 1997).

Acknowledgements

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


Recommended citation
BirdLife International (2024) Species factsheet: Common Grasshopper-warbler Locustella naevia. Downloaded from https://datazone.birdlife.org/species/factsheet/common-grasshopper-warbler-locustella-naevia on 28/12/2024.
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 28/12/2024.