In Japan it inhabits mountain woodland and favors conifer canopies. It is also seen in lowlands in autumn and winter.
It has a short tail and lacks the tie-like black stripe down the breast and belly. It is smaller than a Japanese tit.
Near Örebro in south-central Sweden, researchers recorded Coal Tit breeding in nest boxes in a mixed coniferous-deciduous forest. The long-running nest-box study began in 1948; its Coal Tit records span 1949–2012. First-egg dates ranged from 18 April to 10 May, with a mean of 5 May. In the second half of the study, laying dates advanced by about 0.35 days per year, and years with warmer mean April temperatures had earlier laying.
The 103 first clutches averaged 8.55 eggs, and first broods averaged 7.25 fledged young. There were 13 second clutches, 12.6% of the 103 first clutches; they averaged 7.23 eggs. Seven checked second broods averaged 6.71 fledged young. Nest boxes were placed about 2.5 m above ground and checked about weekly during the breeding season.
IUCN Red List (BirdLife DataZone) · Least Concern (LC) · Global
BirdLife International’s 2024 global IUCN Red List assessment classifies the Coal Tit as Least Concern (LC). Its global population trend is listed as stable.