Eurasian Blue Tit

• Its clutch can exceed a dozen eggs, which is exceptional for a bird of eleven grams.
• The female covers the first eggs with nest material until she has only one or two left to lay, at which point she starts to incubate.
• It takes to nest boxes so readily that putting them up has halted the species' decline in some areas.

Skeleton type

Vertebrate - internal bony skeleton (bird)

Habitat & environment

Anywhere with trees: deciduous and mixed woodland, riverside groves, dehesas, orchards, parks and city gardens. It avoids the interior of pine woods. In winter it is also abundant in reedbeds

Size at birth

The chicks hatch blind and naked

Gestation / incubation

12-16 days, by the female alone, whom the male feeds at the nest. The chicks fledge at three weeks

Litter / clutch size

6-12 white eggs with reddish speckling, one of the largest clutches of any European bird in proportion to its size. Usually a single brood a year

Sources consulted: SEO/BirdLife (ficha y III Atlas de las aves en época de reproducción en España); IUCN Red List; Asturnatura; Salvador 2016, Enciclopedia Virtual de los Vertebrados Españoles (MNCN-CSIC); Wandosell, Remacha y Pérez-Tris 2022

Best time: All year round; the rut begins in late winter