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 stable, 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.
In Europe, the breeding population is estimated to number 7,480,000-14,600,000 pairs, which equates to 15,000,000-29,300,000 mature individuals (BirdLife International 2015). Europe forms 45% of the global range, so a very preliminary estimate of the global population size is 33,000,000-65,100,000 mature individuals, although further validation of this estimate is needed.
In Europe, trends between 1980 and 2013 show that populations have undergone a moderate increase (EBCC 2015). The overall population trend is suspected to be stable in the absence of evidence for any declines or substantial threats.
Garrulus glandarius is distributed widely across Europe and into Morocco and Algeria, its' range continues east into the Urals and northern Middle East, through
Azerbaijan and Mongolia into China, Korea and Japan.
This species inhabits woodlands and forests of all kinds, especially beech (Fagus) and hornbeam (Carpinus), although oak (Quercus) is preferred. It can also be found in parks, orchards and large gardens. Northern populations also occur in conifers and birch (Betula) forest. In most of Europe, egg-laying occurs mainly from mid-April. The nest is built by both sexes and is a well-constructed, platform of twigs around a relatively deep cup, lined with soft plant materials. It is usually placed four to six metres above ground and often at the junction of substantial branch and main trunk. Clutches are typically five to seven eggs. It is omnivorous, feeding mostly on invertebrates during the breeding season. It also takes eggs and nestlings of a range of birds up to the size of a sparrowhawk (Accipiter) and a wide variety of seeds and berries, especially in autumn and winter, including grain, beech mast, chestnuts and acorns. Throughout the autumn and into winter it builds up caches of acorns, burying them individually in leaf litter on forest floor or beneath clumps of brambles or ferns, and has been estimated that a single bird could store c. 3000 acorns in one month (Madge 2009). The species is mainly resident with irregular movements, including irruptions and seasonal altitudinal movements (Madge 2009).
The species's colourful blue wing feathers became very fashionable in the early 20th century, both as hat decoration and in the making of flies for salmon-fishing. It was also long persecuted by gamekeepers and farmers due to its habit of raiding nests, although persecution is now much less widespread (Madge 2009).
Conservation Actions Underway
EU Birds Directive Appendix II. There are currently no known specific conservation measures for this species within Europe.
Conservation Actions Proposed
No conservation measures are currently needed for this species within Europe.
Text account compilers
Butchart, S., Ekstrom, J., Ashpole, J, Derhé, M., Wheatley, H.
BirdLife International (2021) Species factsheet: Garrulus glandarius. Downloaded from http://www.birdlife.org on 06/03/2021. Recommended citation for factsheets for more than one species: BirdLife International (2021) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 06/03/2021.