• The maximum lifespan of the eurasian blue tit reaches 15 years. This is a record among birds of its size.

The Eurasian blue tit’s typical lifespan ranges from 11 years to 18 years and 3 months, although the maximum recorded lifespan is 14 years and 7 months, with a theoretical lifespan of between 10 years and 13 years and 4 months; the species reaches sexual maturity between 9 months and 1 week and 1 year and 3 months. Development begins with an “embryo” stage, during which the embryo develops inside an egg, consuming no food and relying entirely on parental warmth. The “nestling” stage follows, lasting from 2 weeks and 2 days to 3 weeks, where the young bird is in the nest and fed insects by its parents, growing rapidly and developing down feathers before acquiring plumage. Then comes the “rapid growth post-fledging” stage, which lasts from 3 weeks to 1 year, as the young bird learns to fly and forage independently, exhibiting less vibrant plumage than adults. The "adult" stage begins when the bird is capable of reproduction, lasting from 1 to 9 years, during which it actively forages, builds nests, and raises young.