The Great tit (Parus major) is a widespread and common songbird throughout Europe, the Middle East, Central Asia, and east across the Palearctic to the Amur River, south to parts of North Africa. It has adapted well to human changes in the environment and is a common and familiar bird in urban parks and gardens. It is also an important study species in ornithology.
The Great tit has a distinctive appearance that makes it easy to recognize. The nominate race has a bluish-black crown, black neck, throat, bib, and head, and white cheeks and ear coverts. The breast is bright lemon-yellow and there is a broad black mid-line stripe running from the bib to the vent. There is a dull white spot on the neck turning to greenish yellow on the upper nape. The rest of the nape and back are green-tinged with olive. The wing-coverts are green, and the rest of the wing is bluish-grey with a white wing bar. The tail is bluish-grey with white outer tips. The plumage of the female is similar to that of the male except that the colors are overall duller.
Great tits have a wide distribution across much of Eurasia. They can be found across all of Europe except for Iceland and northern Scandinavia, including numerous Mediterranean islands. In North Africa, they live in Morocco, Algeria, and Tunisia. They also occur across the Middle East, and parts of Central Asia from northern Iran and Afghanistan to Mongolia, as well as across northern Asia from the Urals as far east as northern China and the Amur Valley. Great tits inhabit open deciduous woodland, mixed forests, forest edges, and gardens. In northern Siberia, they live in boreal taiga. In North Africa, they prefer oak forests as well as stands of Atlas cedar and even palm groves. In the east of their range, Great tits favor riverine willow and birch forest, as well as low scrubland and oases.
Great tits are generally not migratory. Pairs will usually remain near or in their territory year-round, even in the northern parts of their range. Young birds will disperse from their parents' territory, but usually not far. Great tits are gregarious birds that are active during the day and roost in flocks at night. They often forage on the ground and along with other tits, readily join winter mixed-species foraging flocks. Great tits are vocal birds and have up to 40 types of calls and songs. The calls are generally the same between the sexes, but the male is much more vocal and the female rarely calls. Soft single notes such as "pit", "spick", or "chit" are used as contact calls. A loud "tink" is used by adult males as an alarm or in territorial disputes. One of the most familiar is a "teacher, teacher", often likened to a squeaky wheelbarrow wheel, which is usually used in proclaiming ownership of a territory.
Great tits are carnivores and herbivores. In the summer, they are primarily insectivorous, feeding on insects and spiders including cockroaches, grasshoppers and crickets, lacewings, earwigs, bugs, ants, flies, caddisflies, beetles, scorpionflies, harvestmen, bees and wasps, snails, and woodlice. In autumn and winter, Great tits add berries and seeds to their diet. Where it is available they will readily take table scraps, peanuts, and sunflower seeds from bird tables.
Great tits are monogamous breeders; they form pairs and establish breeding territories. These territories are established in late January and defense begins in late winter or early spring. The time of breeding varies by a number of factors, most importantly location. Most breeding occurs between January and September; in Europe, the breeding season usually begins after March. In Israel, it may occur from October to December. Great tits nest in a cavity that is usually inside a tree, although occasionally in a wall or rock face, and they will readily take to nest boxes. In most years the pair will raise two broods. The nest inside the cavity is built by the female and is made of plant fibers, grasses, moss, hair, wool, and feathers. The number in the clutch is usually 5 to 12 eggs. The eggs are white with red spots. The female undertakes all incubation duties and is fed by the male during this time. The bird is a close sitter, hissing when disturbed. The incubation period is between 12 and 15 days. The chicks are hatched unfeathered and blind. They are fed by both parents, usually receiving 6 to 7 g (0.21-0.25 oz) of food a day. The chicks stay in the nest for 16-22 days and become independent of the parents 8 days after fledging. Feeding of the fledgling may continue after independence; it may last up to 25 days in chicks from the first brood and as long as 50 days in the second brood.
The Great tit doesn't face major threats at present and is not considered to be threatened. However, the species may suffer from habitat loss and changes in climate which may lead to lowered reproductive success.
According to the IUCN Red List, the total population size of the Great tit is around 433,300,000-703,300,000 mature individuals. In Europe, the breeding population consists of 65,100,000-106,000,000 pairs, which equates to 130,000,000-211,000,000 mature individuals. Currently, this species is classified as Least Concern (LC) on the IUCN Red List, and its numbers today are increasing.