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.
In Europe, the breeding population is estimated to number 14,900,000-22,700,000 pairs, which equates to 29,700,000-45,500,000 mature individuals (BirdLife International 2015). Europe forms c.55% of the global range, so a very preliminary estimate of the global population size is 54,000,000-83,000,000 mature individuals, although further validation of this estimate is needed.
The population is declining in North and Central Europe owing to habitat conversion, cooler summers, and decreasing insect populations caused by pollution and insecticides. In Europe, trends between 1980 and 2013 show that populations have undergone a moderate decline (EBCC 2015).
This species inhabits almost any open woodland or timbered area with raised perches providing an open view. During the breeding season it favours well-spaced mature trees to younger trees and bushes, and thus has adapted well to avenues, parks, gardens, orchards and other man-made habitats, as well as occupying many types of deciduous or coniferous woodland. It is also found at woodland edges, in forest glades, clearings and burnt patches, and in trees along streams, rivers and edges of standing water. The breeding season in Europe is from mid-May to mid-August, mainly May-June farther east and April-July in north-west Africa. The nest is a bulky cup of loosely piled fine twigs, rootlets, dead leaves, pieces of decaying bark, moss, dry grass, lichens and fibres, bound with hair and lined with hair, feathers and finer material. It is sited above the ground on a natural or artificial ledge, in a niche, at the base of a basket-shaped tuft of twigs against a tree trunk, in a hole in a tree, branch or stump, in creeper against a tree or wall, or on top of a flat branch. Clutches are two to seven eggs, but most commonly four to six. It is insectivorous, feeding mainly on flying insects, especially flies (Diptera) and hymenopterans but will also take other invertebrates and some fruits. The species is migratory, wintering in sub-Saharan Africa (Taylor 2015).
In north-west Europe, it is thought that declines may be due to a long sequence of generally cooler summers, or adverse factors such as biocide-induced reductions or contamination of insect populations, removal of old trees and general habitat deterioration (Taylor 2015).
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
As the causes of declines are uncertain, further research is needed to investigate possible factors. The species would also benefit from the protection of its favoured mature woodland habitats, a reduced use of broad-spectrum insecticides and the maintenance of mature trees in farmland, parks and gardens (Tucker and Heath 1994).
Text account compilers
Ashpole, J, Ekstrom, J., Butchart, S.
BirdLife International (2019) Species factsheet: Muscicapa striata. Downloaded from http://www.birdlife.org on 18/07/2019. Recommended citation for factsheets for more than one species: BirdLife International (2019) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 18/07/2019.