LC
Eurasian Blue Tit Cyanistes caeruleus



Justification

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 increasing, 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% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern.

Trend justification
The population is estimated to be increasing following recorded range expansions (del Hoyo et al. 2007). In Europe, trends between 1980 and 2013 show that populations have undergone a moderate increase (EBCC 2015).

Ecology

This species inhabits broad-leaved woodland, as well as coppices, parks and gardens. It uses deciduous woodland principally containing oak (Quercus) and birch (Betula) and generally avoids large stands of conifers (Gosler et al. 2013), however in the Canary Islands it also frequents montane conifer woodland. Provided suitable nest-holes are present this species will even occur in inner cities. The breeding season is April to late June. The nest is built by the female and is mostly a cup of moss, dried grass, fine bark strips, plant fibres, leaves, animal hair and feathers, placed in a hole or a cleft in a tree or post or other artificial site. Nestboxes are widely used. In Europe clutches are generally seven to thirteen eggs (Gosler et al. 2013). It feeds primarily on insects and spiders, as well as fruits, seeds, nectar and pollen. The diet varies with seasonal and other changes in food abundance. The species is essentially resident though in the centre and north of its range it makes irregular eruptive movements (Snow and Perrins 1998) and seasonal altitudinal shifts (Gosler et al. 2013).

Threats

The species is subject to high annual and local fluctuations driven by habitat carrying capacity, breeding success, winter mortality (Hagemeijer and Blair 1997) and competition from Parus major (Gosler et al. 2013).

Conservation actions

Conservation Actions Underway
Bern Convention Appendix II. Provision of food at bird tables is thought to account for a considerable proportion of winter sustenance, enabling large numbers to survive hard winters or severe weather (Gosler et al. 2013).


Conservation Actions Proposed
Currently no conservation measures are needed for this species.

Acknowledgements

Text account compilers
Ashpole, J, Butchart, S., Ekstrom, J., Symes, A. & Taylor, J.


Recommended citation
BirdLife International (2017) Species factsheet: Cyanistes caeruleus. Downloaded from http://www.birdlife.org on 18/10/2017. Recommended citation for factsheets for more than one species: BirdLife International (2017) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 18/10/2017.