Eurasian blue tit

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Eurasian blue tit
Eurasian blue tit Lancashire.jpg
A Eurasian blue tit in Lancashire, United Kingdom
The calls of a blue tit
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Passeriformes
Family: Paridae
Genus: Cyanistes
Species:
C. caeruleus
Binomial name
Cyanistes caeruleus
CyanistesCaeruleusDistribution.png
  Eurasian blue tit range
   African blue tit range
Synonyms

Parus caeruleus Linnaeus, 1758

Eurasian blue tit in Sweden, April 2018 Parus caeruleus EM1B1832 (40967518404).jpg
Eurasian blue tit in Sweden, April 2018

The Eurasian blue tit (Cyanistes caeruleus) [2] is a small passerine bird in the tit family, Paridae. It is easily recognisable by its blue and yellow plumage and small size.

Eurasian blue tits, usually resident and non-migratory birds, are widespread and a common resident breeder throughout temperate and subarctic Europe and the western Palearctic in deciduous or mixed woodlands with a high proportion of oak. They usually nest in tree holes, although they easily adapt to nest boxes where necessary. Their main rival for nests and in the search for food is the larger and more common great tit.

The Eurasian blue tit prefers insects and spiders for its diet. Outside the breeding season, they also eat seeds and other vegetable-based foods. The birds are famed for their acrobatic skills, as they can hold on to the outermost branches of trees and shrubs and hang upside down when looking for food.

Taxonomy

The Eurasian blue tit was described by Carl Linnaeus in 1758 in the 10th edition of his Systema Naturae under the binomial name Parus caeruleus. [3] Parus is the classical Latin for a tit and caeruleus is the Latin for dark blue or cerulean. [4] Two centuries earlier, before the introduction of the binomial nomenclature, the same Latin name had been used by the Swiss naturalist Conrad Gesner when he described and illustrated the blue tit in his Historiae animalium of 1555. [5]

In 2005, analysis of the mtDNA cytochrome b sequences of the Paridae indicated that Cyanistes was an early offshoot from the lineage of other tits, and more accurately regarded as a genus rather than a subgenus of Parus . [6] The current genus name, Cyanistes, is from the Ancient Greek kuanos, "dark blue". [4] The African blue tit (Cyanistes teneriffae) was formerly considered conspecific.

Subspecies

There are currently at least nine recognised subspecies: [7]

Hybrids

Pleske's tit (Cyanistes × pleskei) is a common interspecific hybrid between this species and the azure tit (Cyanistes cyanus), in western Russia. The cap is usually darker than the azure tit, and the tail is paler than the Eurasian blue tit. [9]

Description

The Eurasian blue tit is usually 12 cm (4.7 in), long with a wingspan of 18 cm (7.1 in) for both sexes, and weighs about 11 g (0.39 oz). [10] A typical Eurasian blue tit has an azure-blue crown and dark blue line passing through the eye, and encircling the white cheeks to the chin, giving the bird a very distinctive appearance. The forehead and a bar on the wing are white. The nape, wings and tail are blue and the back is yellowish green. The underparts are mostly sulphur-yellow with a dark line down the abdomen—the yellowness is indicative of the number of yellowy-green caterpillars eaten, due to high levels of carotene pigments in the diet. [11] The bill is black, the legs bluish grey, and the irides dark brown. The sexes are similar and often indistinguishable to human eyes, but under ultraviolet light, males have a brighter blue crown. [12] Young blue tits are noticeably more yellow.

Distribution and habitat

Reported range from observations reported to eBird
Year-Round Range
Summer Range
Winter Range Eurasian Blue Tit ebird data map.png
Reported range from observations reported to eBird
  Year-Round Range
  Summer Range
  Winter Range
Blue tit displaying aggression during ringing Blue tit displaying aggresion during ringing.jpg
Blue tit displaying aggression during ringing

There are currently around 20–44 million pairs in Europe. [13]

The Eurasian blue tit and the related hybrids are considered native species in areas of the European continent with a mainly temperate or Mediterranean climate, and in parts of the Middle East. These areas include Ireland, the United Kingdom and most of the European Union and EFTA (except Malta, where they are considered vagrant, and Iceland, where they are absent), plus: Albania, Algeria, Andorra, Armenia, Azerbaijan, Belarus, Bosnia and Herzegovina, Georgia, Iran, Iraq, Jordan, Kazakhstan, Lebanon, Libya, Moldova, Montenegro, Morocco, North Macedonia, Russia, San Marino, Serbia, Syria, Tunisia, Turkey, Vatican City and Ukraine. [14]

In Great Britain the Eurasian blue tit can be found in a variety of environments, and is typically found in deciduous woodland, parks, gardens and even in the centre of towns. [15]

Behaviour and ecology

Eurasian blue and great tits form mixed winter flocks, and the former are perhaps the better gymnasts in the slender twigs. A Eurasian blue tit will often ascend a trunk in short jerky hops, reminiscent of a treecreeper. As a rule the bird roosts in ivy or evergreens, but in harsh winters will roost wherever there is a suitable small hole, be it in a tree or nesting box. They are very agile and can hang from almost anywhere.

This is a common and popular European garden bird, due to its perky acrobatic performances when feeding on nuts or suet. It swings beneath the holder, calling "tee, tee, tee" or a scolding "churr".

Breeding

The Eurasian blue tit will nest in any suitable hole in a tree, wall, or stump, or an artificial nest box, often competing with house sparrows or great tits for the site. Few birds more readily accept the shelter of a nesting box; the same hole is returned to year after year, and when one pair dies another takes possession. It is estimated by the RSPB that there are 3,535,000 breeding pairs in the UK. [13]

During the incubation period, female blue tits perform all of the incubation, however the male feeds the female during this time. During the nestling period both female nest attendance and male feeding rate are higher in the morning, declining throughout the day. [16] Although socially monogamous, blue tits regularly engage in extra-pair copulations with other individuals. [17]

Eggs are 14–18 mm (0.55–0.71 in) long and 10.7–13.5 mm (0.42–0.53 in) wide. Egg size appears to depend mostly on the size of individual females and secondarily on habitat, with smaller eggs found at higher altitudes. The clutch's total weight can be 1.5 times as heavy as the female bird. [18]

Juvenile in Pimlico, London Blue tit (Cyanistes caeruleus) juvenile.jpg
Juvenile in Pimlico, London

A study found that the timing of breeding in blue tits is related to the expression of nestling carotenoid‐based coloration, which could play a role in offspring–parent communication. [19]

The bird is a close sitter, hissing and biting at an intruding finger. In the South West of England such behaviour has earned the Eurasian blue tit the colloquial nickname "Little Billy Biter" or "Billy Biter", originating from the UK. [20] When protecting its eggs it raises its crest, but this is a sign of excitement rather than anger, for it is also elevated during nuptial display. The nesting material is usually moss, wool, hair and feathers, and the eggs are laid in April or May. The number in the clutch is often very large, but seven or eight are normal, clutch size varies with latitude and other geographic parameters. Some bigger clutches may be laid by two or even more hens in some locations but single hen clutches of 14 have been verified in the UK. It is not unusual for a single bird to feed the chicks in the nest at a rate of one feed every 90 seconds during the height of the breeding season. In winter they form flocks with other tit species.

In an analysis carried out using ring-recovery data in Britain, the survival rate for juveniles in their first year was 38%, while the adult annual survival rate was 53%. [21] From these figures the typical lifespan is only three years. [10] Within Britain, the maximum recorded age is 10 years and 3 months for a bird that was ringed in Bedfordshire. [22] The maximum recorded age overall is 11 years and 7 months for a bird in the Czech Republic. [23]

Diet

Eating peanuts from a garden bird feeder in England
Eurasian blue tit eating peanuts from a string, Italy Eurasian blue tit - 2018.JPG
Eurasian blue tit eating peanuts from a string, Italy

The Eurasian blue tit feeds on many insects such as beetles and flies, other small invertebrates like earthworms and spiders and their larvae, though it is fond of young buds and fruits of various trees, especially when insect prey is scarce, and may pull them to bits in the hope of finding insects, mostly from redcurrant, ivy berries, juniper berries, and mistletoe berries. [24] It is a well-known predator of many Lepidoptera species including the Wood Tiger moth. No species, however, destroys more coccids and aphids, the worst foes of many plants. It takes leaf miner grubs and green tortrix moths (Tortricidae). In common with all members of the family, seeds are also eaten.

Voice

Calls of a blue tit

Eurasian blue tits use songs and calls throughout the year. [25] Songs are mostly used in late winter and spring to defend the territory or to attract mates. Calls are used for multiple reasons. [26] Communication with other Eurasian blue tits is the most important motivation for the use of calls. They inform one another on their location in trees by means of contact-calls. They use alarm-calls to warn others (including birds of other species such as the great tit, the European robin or the treecreeper) about the presence of predators in the neighbourhood. Scolding, for example, is used when a ground predator (e.g. fox, cat or dog), a low flying predator or a perched owl are noticed. [27] Sometimes this is followed by mobbing behaviour in which birds gather together in flocks to counter a predator. The alarm-whistle warns other birds about the proximity of a Eurasian sparrowhawk, a northern goshawk, a common buzzard or other flying predators that form a potential danger in the air. A series of high-pitched 'zeedling' notes are given by both partners before and during copulation. [28] The begging-call is used by juveniles to beg for food from parents.

Learnt behaviours

An interesting example of culturally transmitted learning in birds was the phenomenon dating from the 1920s of blue tits teaching one another how to open traditional British milk bottles with foil tops, to get at the cream underneath. [29] Such behaviour has been suppressed recently by the gradual change of human dietary habits (low-fat or skimmed milk instead of full-fat), and the way of getting them (from a supermarket in plastic containers with hard plastic lids, instead of the milkman). [30] In addition, the instinct to strip bark from trees in search of insects has developed into a tendency to peel building materials such as thatch, wallpaper, stucco and window putty. [31]

Predators and natural threats

The small size of the Eurasian blue tit makes it vulnerable to prey by larger birds such as jays who catch the vulnerable fledglings when they leave the nest. The most important predator is probably the sparrowhawk, closely followed by the domestic cat. Nests may be robbed by mammals such as weasels and red squirrels, as well as introduced grey squirrels in the UK.

The successful breeding of chicks is dependent on sufficient supply of green caterpillars as well as satisfactory weather. Breeding seasons may be affected badly if the weather is cold and wet between May and July, particularly if this coincides with the emergence of the caterpillars on which the nestlings are fed. [32]

Parasites

A bald blue tit with mite A bald blue tit with mite.jpg
A bald blue tit with mite

Eurasian blue tits are known to be host to feather mites, and rarely lice and flat flies. In Europe, the only feather mite species known to live on the blue tit host is Proctophyllodes stylifer. However, this mite seems to be of no concern to the bird as, until now, it is only known to feed on dead feather tissue. P. stylifer lives all its developmental stages, i.e. egg, larva, protonymph, tritonymph and adult, within the plumage of the same host. The usual sites where P. stylifer is encountered are the remiges and the rectrices of the bird where they can be found tandemly positioned between the barbs of the rachis. [33]

Status and conservation

The Eurasian blue tit is classified as a least concern species on the IUCN Red List (version 3.1), [1] and as a Green Status species, since 1996, by the Royal Society for the Protection of Birds in the United Kingdom. [10] [13]

Cultural significance

The Eurasian blue tit has appeared on many stamps and ornaments. Its most recent appearance on a British stamp was the 2010 Birds of Britain series. [34]

Related Research Articles

<span class="mw-page-title-main">Eurasian magpie</span> Species of bird

The Eurasian magpie or common magpie is a resident breeding bird throughout the northern part of the Eurasian continent. It is one of several birds in the crow family (corvids) designated magpies, and belongs to the Holarctic radiation of "monochrome" magpies. In Europe, "magpie" is used by English speakers as a synonym for the Eurasian magpie: the only other magpie in Europe is the Iberian magpie, which is limited to the Iberian Peninsula. Despite having a shared name and similar colouration, it is not closely related to the Australian Magpie.

<span class="mw-page-title-main">Common cuckoo</span> Species of bird

The cuckoo, common cuckoo, European cuckoo or Eurasian cuckoo is a member of the cuckoo order of birds, Cuculiformes, which includes the roadrunners, the anis and the coucals.

<span class="mw-page-title-main">Penduline tit</span> Family of birds

The penduline tits constitute the family, Remizidae, of small passerine birds, related to the true tits. All but the verdin make elaborate bag nests hanging from trees, usually over water.

<span class="mw-page-title-main">Tit (bird)</span> Family of small passerine birds

The tits, chickadees, and titmice constitute the Paridae, a large family of small passerine birds which occur mainly in the Northern Hemisphere and Africa. Most were formerly classified in the genus Parus.

<span class="mw-page-title-main">Eurasian chaffinch</span> Species of bird

The Eurasian chaffinch, common chaffinch, or simply the chaffinch is a common and widespread small passerine bird in the finch family. The male is brightly coloured with a blue-grey cap and rust-red underparts. The female is more subdued in colouring, but both sexes have two contrasting white wing bars and white sides to the tail. The male bird has a strong voice and sings from exposed perches to attract a mate.

<span class="mw-page-title-main">Marsh tit</span> Species of bird

The marsh tit is a Eurasian passerine bird in the tit family Paridae and genus Poecile, closely related to the willow tit, Père David's and Songar tits. It is a small bird, around 12 cm (4.7 in) long and weighing 12 g (0.42 oz), with a black crown and nape, pale cheeks, brown back and greyish-brown wings and tail. Between 8 and 11 subspecies are recognised. Its close resemblance to the willow tit can cause identification problems, especially in the United Kingdom where the local subspecies of the two are very similar: they were not recognised as separate species until 1897.

<span class="mw-page-title-main">Coal tit</span> Species of bird

The coal tit or cole tit,, is a small passerine bird in the tit family, Paridae. It is a widespread and common resident breeder in forests throughout the temperate to subtropical Palearctic, including North Africa. The black-crested tit is now usually included in this species.

<span class="mw-page-title-main">Willow tit</span> Species of passerine bird in the tit family Paridae

The willow tit is a passerine bird in the tit family, Paridae. It is a widespread and common resident breeder throughout temperate and subarctic Europe and across the Palearctic. The plumage is grey-brown and off-white with a black cap and bib. It is more of a conifer specialist than the closely related marsh tit, which explains it breeding much further north. It is resident, and most birds do not migrate.

<span class="mw-page-title-main">Crested tit</span> Species of bird

The crested tit or European crested tit, is a passerine bird in the tit family Paridae. It is a widespread and common resident breeder in coniferous forests throughout central and northern Europe and in deciduous woodland in France and the Iberian peninsula. In Great Britain, it is chiefly restricted to the ancient pinewoods of Inverness and Strathspey in Scotland, and seldom strays far from its haunts. A few vagrant crested tits have been seen in England. It is resident, and most individuals do not migrate.

<span class="mw-page-title-main">Great tit</span> Passerine bird in the tit family Paridae

The great tit is a small passerine bird in the tit family Paridae. It is a widespread and common species throughout Europe, the Middle East, Central Asia and east across the Palearctic to the Amur River, south to parts of North Africa where it is generally resident in any sort of woodland; most great tits do not migrate except in extremely harsh winters. Until 2005 this species was lumped with numerous other subspecies. DNA studies have shown these other subspecies to be distinct from the great tit and these have now been separated as two distinct species, the cinereous tit of southern Asia, and the Japanese tit of East Asia. The great tit remains the most widespread species in the genus Parus.

<span class="mw-page-title-main">Eurasian sparrowhawk</span> Species of bird

The Eurasian sparrowhawk, also known as the northern sparrowhawk or simply the sparrowhawk, is a small bird of prey in the family Accipitridae. Adult male Eurasian sparrowhawks have bluish grey upperparts and orange-barred underparts; females and juveniles are brown above with brown barring below. The female is up to 25% larger than the male – one of the greatest size differences between the sexes in any bird species. Though it is a predator which specialises in catching woodland birds, the Eurasian sparrowhawk can be found in any habitat and often hunts garden birds in towns and cities. Males tend to take smaller birds, including tits, finches, and sparrows; females catch primarily thrushes and starlings, but are capable of killing birds weighing 500 g (18 oz) or more.

<span class="mw-page-title-main">Short-toed treecreeper</span> Species of bird

The short-toed treecreeper is a small passerine bird found in woodlands through much of the warmer regions of Europe and into north Africa. It has a generally more southerly distribution than the other European treecreeper species, the common treecreeper, with which it is easily confused where they both occur. The short-toed treecreeper tends to prefer deciduous trees and lower altitudes than its relative in these overlap areas. Although mainly sedentary, vagrants have occurred outside the breeding range.

<span class="mw-page-title-main">Long-tailed tit</span> Species of bird in Europe and Asia

The long-tailed tit, also named long-tailed bushtit, is a common bird found throughout Europe and the Palearctic. The genus name Aegithalos was a term used by Aristotle for some European tits, including the long-tailed tit.

<span class="mw-page-title-main">Azure tit</span> Species of bird

The azure tit is a passerine bird in the tit family Paridae. It is a widespread and common resident breeder throughout Russia, Central Asia, northwest China, Manchuria, and Pakistan.

<span class="mw-page-title-main">Siberian jay</span> Species of bird

The Siberian jay is a small jay with a widespread distribution within the coniferous forests in North Eurasia. It has grey-brown plumage with a darker brown crown and a paler throat. It is rusty-red in a panel near the wing-bend, on the undertail coverts and on the sides of the tail. The sexes are similar. Although its habitat is being fragmented, it is a common bird with a very wide range so the International Union for Conservation of Nature has assessed its conservation status as being of "least concern".

<span class="mw-page-title-main">Eurasian penduline tit</span> Species of bird

The Eurasian penduline tit or European penduline tit is a passerine bird of the genus Remiz. It is relatively widespread throughout the western Palearctic. It is migratory in the northern part of its range but resident in the southern part.

<span class="mw-page-title-main">African blue tit</span> Species of bird

The African blue tit is a species of bird in the family Paridae. It is found in northern Africa, Pantelleria (Italy) and the Canary Islands (Spain). Its natural habitat is temperate forests. This species and the Eurasian blue tit were formerly considered conspecific. The status of this species has not been assessed because it is noted to be common on the islands of Tenerife and Gran Canaria. The species has been used in many research studies due to its island populations and relevance to evolutionary hypotheses.

<span class="mw-page-title-main">Southern black tit</span> Species of bird

The southern black tit or simply black tit is a species of bird in the tit family Paridae, which is native to woodland habitats in southern Africa.

<i>Cyanistes</i> Genus of birds

Cyanistes is a genus of birds in the tit family Paridae. The genus was at one time considered as a subgenus of Parus. In 2005 an article describing a molecular phylogenetic study that had examined mitochondrial DNA sequences from members of the tit family, proposed that a number of subgenera including Cyanistes be elevated to genus status. This proposal was accepted by the International Ornithologists' Union and the British Ornithologists' Union.

<span class="mw-page-title-main">Cinereous tit</span> Species of bird

The cinereous tit is a species of bird in the tit family Paridae. This species is made up of several populations that were earlier treated as subspecies of the great tit. These birds are grey backed with white undersides. The great tit in the new sense is distinguishable by the greenish-back and yellowish underside. The distribution of this species extends from parts of West Asia across South Asia and into Southeast Asia.

References

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