Great Tit

The great tit was first described under its current binomial name by Carl Linnaeus in his 1758 10th edition of Systema Naturae. Its scientific name is derived from the Latin parus "tit" and maior "larger". Francis Willughby had used the name in the 17th century. were once lumped with the great tit but recent genetic and bioacoustic studies now separate that group as a distinct species]] The great tit was formerly considered to range from Britain to Japan and south to the islands of Indonesia, with 36 described subspecies ascribed to four main species groups. The major group comprised 13 subspecies across Europe, temperate Asia and north Africa; the minor group's nine subspecies occurred from southeast Russia and Japan into northern southeast Asia and the 11 subspecies in the cinereus group were found from Iran across south Asia to Indonesia. The three bokharensis subspecies were often treated as a separate species, Parus bokharensis, the Turkestan tit. This form was once thought to form a ring species around the Tibetan Plateau, with gene flow throughout the subspecies, but this theory was abandoned when sequences of mitochondrial DNA were examined, finding that the four groups were distinct (monophyletic) and that the hybridisation zones between the groups were the result of secondary contact after a temporary period of isolation. A study published in 2005 confirmed that the major group was distinct from the cinereus and minor groups and that along with P. m. bokharensis it diverged from these two groups around 1.5 million years ago. The divergence between the bokharensis and major groups was estimated to have been about half a million years ago. The study also examined hybrids between representatives of the major and minor groups in the Amur Valley where the two meet. Hybrids were rare, suggesting that there were some reproductive barriers between the two groups. The study recommended that the two eastern groups be split out as new species, the cinereous tit (Parus cinereus), and the Japanese tit (Parus minor), but that the Turkestan tit be lumped in with the great tit. This taxonomy has been followed by some authorities, for example the IOC World Bird List. The Handbook of the Birds of the World volume treating the Parus species went for the more traditional classification, treating the Turkestan tit as a separate species but retaining the Japanese and cinereous tits with the great tit, The nominate subspecies of the great tit is the most widespread, its range stretching from the Iberian Peninsula to the Amur Valley and from Scandinavia to the Middle East. The other subspecies have much more restricted distributions; four are confined to islands, while the rest of the P. m. major subspecies represent former glacial refuge populations. The dominance of a single, morphologically uniform subspecies over such a large area suggests that the nominate race rapidly recolonised a large area after the last glacial epoch. This hypothesis is supported by genetic studies which suggest a geologically recent genetic bottleneck followed by a rapid population expansion.

There are currently 15 recognised subspecies of great tit: is found across the British Isles. *P. m. major, described by Linnaeus in 1758, is found throughout much of Europe, Asia Minor, northern and eastern Kazakhstan, southern Siberia and northern Mongolia, as far as the mid-Amur Valley. *P. m. excelsus, described by Buvry in 1857, is found in northwestern Africa. *P. m. corsus, described by Kleinschmidt in 1903, is found in Portugal, southern Spain, and Corsica. *P. m. mallorcae, described by von Jordans in 1913, is found in the Balearic Islands. *P. m. ecki, described by von Jordans in 1970, is found on Sardinia. *P. m. niethammeri, described by von Jordans in 1970, is found on Crete. *P. m. aphrodite, described by Madarász in 1901, is found in southern Italy, southern Greece, Cyprus and the Aegean Islands. *P. m. terrasanctae was described by Hartert in 1910. It is found in Lebanon, Israel, Jordan and Syria. *P. m. karelini, described by Zarudny in 1910, is found in southeastern Azerbaijan and northwestern Iran. *P. m. blandfordi was described by Pražák in 1894.

The great tit is, like other tits, a vocal bird, and has 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 used in proclaiming ownership of a territory. Tit calls from different geographic regions show some variation, and tits from the two south Asian groups recently split from the great tit do not recognise or react to the calls of the temperate great tits.

in Altenbeken, Germany]] The great tit has a wide distribution across much of Eurasia. It can be found across all of Europe except for Iceland and northern Scandinavia, including numerous Mediterranean islands. In North Africa it lives in Morocco, Algeria and Tunisia. It also occurs 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. The great tit was introduced to the United States, but failed to become established after birds were released near Cincinnati, Ohio between 1872 and 1874. Suggestions that they would be an effective way of controlling codling moths nearly led to their introduction to some new areas, particularly in the United States, but this plan was not implemented. A small population is present in the upper Midwest, believed to be the descendants of birds liberated in Chicago in 2002 along with European goldfinches, Eurasian jays, common chaffinches, European greenfinches, saffron finches, blue tits and Eurasian linnets, although sightings of some of these species pre-date the supposed introduction date. Birds were introduced to the Almaty Province in what is now Kazakhstan in 1960–61 and became established, although their present status is unclear.

===Diet and feeding=== , great tits transport food with their beak, and then transfer it to their feet, where it is held while they eat|alt= Male great tit on branch with sunflower seed]] Great tits are primarily insectivorous in the summer, feeding on insects and spiders which they capture by foliage gleaning. Their larger invertebrate prey include cockroaches, grasshoppers and crickets, lacewings, earwigs, bugs (Hemiptera), ants, flies (Diptera), caddisflies, beetles, scorpionflies, harvestmen, bees and wasps, snails and woodlice. A study published in 2007 found that great tits helped to reduce caterpillar damage in apple orchards by as much as 50%. Nestlings also undergo a period in their early development where they are fed a number of spiders, possibly for nutritional reasons. This behaviour, first noted in 1921, spread rapidly in the next two decades. In 2009, great tits were reported killing, and eating the brains of roosting pipistrelle bats. This is the first time a songbird has been recorded preying on bats. The tits only do this during winter when the bats are hibernating and other food is scarce. They have also been recorded using tools, using a conifer needle in the bill to extract larvae from a hole in a tree.

Great tits are monogamous breeders and establish breeding territories. These territories are established in late January and defence begins in late winter or early spring. Although the great tit is socially monogamous, extra-pair copulations are frequent. One study in Germany found that 40% of nests contained some offspring fathered by parents other than the breeding male and that 8.5% of all chicks were the result of cuckoldry. Adult males tend to have a higher reproductive success compared to sub-adults. ]] s]] Great tits are seasonal breeders. The exact timing 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 there are exceptional records of breeding during the months of October to December. The amount of sunlight and daytime temperatures will also affect breeding timing. One study found a strong correlation between the timing of laying and the peak abundance of caterpillar prey, which is in turn correlated to temperature. On an individual level, younger females tend to start laying later than older females. Great tits are cavity nesters, breeding in a hole that is usually inside a tree, although occasionally in a wall or rock face, and they will readily take to nest boxes. The nest inside the cavity is built by the female, and is made of plant fibres, grasses, moss, hair, wool and feathers. The number in the clutch is often very large, as many as 18, but five to twelve is more common. Clutch size is smaller when birds start laying later, and is also lower when the density of competitors is higher. Second broods tend to have smaller clutches. Insularity also affects clutch size, with great tits on offshore islands laying smaller clutches with larger eggs than mainland birds. The eggs are white with red spots. The female undertakes all incubation duties, and is fed by the male during incubation. The incubation period is between 12 and 15 days. Chicks are fed by both parents, usually receiving of food a day. The nestling period is between 16 and 22 days, with chicks being independent of the parents eight days after fledging. Feeding of the fledgling may continue after independence, lasting up to 25 days in chicks from the first brood, but as long as 50 days in the second brood. Inbreeding depression occurs when the offspring produced as a result of a mating between close relatives show reduced fitness. The reduced fitness is generally considered to be a consequence of the increased expression of deleterious recessive alleles in these offspring. In natural populations of P. major, inbreeding is avoided by dispersal of individuals from their birthplace, which reduces the chance of mating with a close relative.

The Eurasian sparrowhawk is a predator of great tits, with the young from second broods being at higher risk partly because of the hawk's greater need for food for its own developing young. The nests of great tits are raided by great spotted woodpeckers, particularly when nesting in certain types of nest boxes. Other nest predators include introduced grey squirrels (in Britain) and least weasels, which are able to take nesting adults as well. A species of biting louse (Mallophaga) described as Rostrinirmus hudeci was isolated and described in 1981 from great tits in central Europe. The hen flea Ceratophyllus gallinae is exceedingly common in the nests of blue and great tits. It was originally a specialist tit flea, but the dry, crowded conditions of chicken runs enabled it to flourish with its new host. This flea is preferentially predated by the clown beetle Gnathoncus punctulatus,

Great tits have been found to possess special physiological adaptations for cold environments. When preparing for winter months, the great tit can increase how thermogenic (heat producing) its blood is. The mechanism for this adaptation is a seasonal increase in mitochondrial volume and mitochondrial respiration in red blood cells and increased uncoupling of the electron transport from ATP production. Reduced cold injury and heat loss is mediated by the great tits' counter-current vascular arrangements, and peripheral vasoconstriction in major vessels in and around the birds' bill and legs. This mechanism allows uninsulated regions (i.e., bill and legs) to remain close to the surrounding temperature. In response to food restriction, the great tits' bill temperature dropped, and once food availably was increased, bill temperatures gradually returned to normal. Vasoconstriction of blood vessels in the bill not only serves as an energy saving mechanism, but also reduces the amount of heat transferred from core body tissues to the skin (via cutaneous vasodilation), which, in turn, reduces heat loss rate by lowering skin temperature relative to the environment.

The great tit is a popular garden bird due to its acrobatic performances when feeding on nuts or seed. Its willingness to move into nest boxes has made it a valuable study subject in ornithology; it has been particularly useful as a model for the study of the evolution of various life-history traits, particularly clutch size. A study of a literature database search found 1,349 articles relating to Parus major for the period between 1969 and 2002. In adapting to human environments its song has been observed to change in noise-polluted urban environments. In areas with low frequency background noise pollution, the song has a higher frequency than in quieter areas. This tit has expanded its range, moving northwards into Scandinavia and Scotland, and south into Israel and Egypt. The total population is estimated at between 300 and 1,100 million birds in a range of 32.4 million km2 (12.5 million sq mi). While there have been some localised declines in population in areas with poorer quality habitats, its large range and high numbers mean that the great tit is not considered to be threatened, and it is classed as least concern on the IUCN Red List.