
The Great Tit (Parus major) is a small passerine bird in the tit family, widespread across Europe, the Middle East, Central Asia, and parts of North Africa. Typically found in woodlands, it is mostly resident and does not migrate except during harsh winters. In 2005, DNA studies led to the separation of the great tit from other subspecies, establishing the cinereous tit (Parus cinereus) and the Japanese tit (Parus minor) as distinct species. The great tit remains the most widespread species in the genus Parus.
The great tit is a medium-sized bird measuring 12.5 to 14.0 cm. It has a striking appearance, featuring a bluish-black crown, black neck, and bright lemon-yellow breast with a broad black stripe. The female is similar but with duller colors. There are several subspecies, each with slight variations in plumage, such as bill size and coloration.
Male great tits showcase brighter plumage, which can indicate better health and reproductive fitness. The color of their breast correlates with sperm quality, influenced by carotenoid intake from food and environmental factors. Females tend to prefer males with more vibrant colors and wider ventral stripes.
The great tit is widely distributed across much of Eurasia, found throughout Europe except for Iceland and northern Scandinavia, as well as in North Africa (Morocco, Algeria, and Tunisia) and parts of the Middle East and Central Asia. It thrives in various habitats, including open deciduous woodlands, mixed forests, forest edges, gardens, and even dense coniferous forests. In northern Siberia, it inhabits boreal taiga, and in North Africa, it prefers oak forests.
Generally not migratory, great tit pairs tend to stay in their territories year-round, though young birds may disperse nearby. Some populations may become irruptive during harsh winters, moving to regions like the Baltic and southern Balkans. Failed introductions occurred in the United States in the 1870s, but a small population in the upper Midwest is believed to be descendants of a 2002 release in Chicago. In Kazakhstan, the species was successfully introduced in 1960–61, but its current status there is unclear.
Great tits are primarily insectivorous in summer, feeding on insects and spiders captured by gleaning. Their diet includes a variety of invertebrates such as cockroaches, grasshoppers, and bees. During breeding season, they favor protein-rich caterpillars for their young. A 2007 study found that great tits reduced caterpillar damage in apple orchards by up to 50%.
In autumn and winter, they supplement their diet with berries and seeds, often foraging on the ground, especially in years with high beech mast production. They will also consume table scraps and seeds from bird feeders. Great tits use “hold-hammering” to handle larger food items, striking them with their bill to access the edible parts, such as when preparing insects for their young.
Great tits are intelligent and versatile birds known for their problem-solving skills. They learned to break milk bottle caps to access cream, a behavior first observed in 1921, and have been recorded preying on hibernating pipistrelle bats during winter due to food scarcity. They also use tools, such as conifer needles, to extract larvae from trees.
These birds are monogamous and establish territories in late winter or early spring, often returning to the same area in subsequent years. However, extra-pair copulations are common, with studies showing that a significant percentage of nests contain offspring from outside the breeding pair. Adult males generally have higher reproductive success than younger males.
Their breeding season varies by location, typically occurring from January to September in Europe, with exceptional breeding from October to December in Israel. Breeding timing is influenced by sunlight, temperature, and the availability of caterpillar prey, with younger females generally laying eggs later than older ones.
Great tits are cavity nesters, typically breeding in tree holes, although they can also use walls or rock faces, and are attracted to nest boxes. The female builds the nest from plant fibers, grasses, moss, hair, wool, and feathers. Clutch sizes can reach up to 18 eggs, but commonly consist of five to twelve. Factors like delayed laying and high competitor density can lead to smaller clutches. The female incubates the white eggs with red spots, while the male feeds her during this time. Hatching timing can adjust based on prey availability.
Chicks hatch blind and unfeathered, initially exhibiting bright plumage colored by carotenoids. They are fed by both parents, receiving around 6 to 7 grams of food daily. The nestling period lasts 16 to 22 days, with fledglings becoming independent after eight days, though parental feeding might continue longer, especially for second broods. These second broods often have weaker immune systems and lower survival rates.
Inbreeding depression can occur when closely related birds mate, leading to reduced fitness due to harmful recessive alleles. To avoid this, great tits often disperse from their birthplace to prevent mating with relatives.