Eurasian blue tit#Relationship with humans

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. Parus is the classical Latin for a tit and caeruleus is the Latin for dark blue or cerulean. The type locality is Sweden.{{ cite book | editor-last=Paynter | editor-first=Raymond A. Jr | year=1986 | title=Check-list of Birds of the World | volume=12 | publisher=Museum of Comparative Zoology | place=Cambridge, Massachusetts | page=113 | url=https://www.biodiversitylibrary.org/page/14482230 }} 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.

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. The current genus name, Cyanistes, is from the Ancient Greek {{Transliteration|grc|kuanos}}, "dark blue". The African blue tit (Cyanistes teneriffae) was formerly considered to be conspecific.{{Cite journal | last1=Salzburger | first1=W. | last2=Martens | first2=J. | last3=Sturmbauer | first3=C. | date=2002 | title=Paraphyly of the Blue Tit (Parus caeruleus) suggested from cytochrome b sequences | journal=Molecular Phylogenetics and Evolution | volume=24 | issue=1 | pages=19–25 | doi=10.1016/S1055-7903(02)00265-8}}{{cite web| editor1-last=Gill | editor1-first=Frank | editor1-link=Frank Gill (ornithologist) | editor2-last=Donsker | editor2-first=David | editor3-last=Rasmussen | editor3-first=Pamela | editor3-link=Pamela C. Rasmussen | date=February 2025 | title=Waxwings and their allies, tits & penduline tits | work=IOC World Bird List Version 15.2 | url=http://www.worldbirdnames.org/bow/waxwings/ | publisher=International Ornithologists' Union | access-date=7 June 2025 }} The genus Cyanistes now contains three species: the Eurasian blue tit, the African blue tit and the azure tit.

Nine subspecies are recognised. They differ mainly in the colour of the plumage but the variation is usually slight and clinal.{{cite web | last1=Kirwan | first1=P. | last2=Gosler | first2=A. | last3=Clement | first3=P. | last4=Christie | first4=D.A. | last5=Pyle | first5=P. | year=2024 | title=Eurasian Blue Tit (Cyanistes caeruleus), version 1.1 | editor1-last=del Hoyo | editor1-first=J. | editor2-last=Elliott | editor2-first=A. | editor3-last=Sargatal | editor3-first=J. | editor4-last=Christie | editor4-first=D.A. | editor5-last=de Juana | editor5-first=E. | work=Birds of the World | location=Ithaca, NY, USA | publisher=Cornell Lab of Ornithology | url=https://doi.org/10.2173/bow.blutit.01.1 | access-date=8 June 2025 | url-access=subscription }}

• C. c. obscurus – (Pražák, 1894): found in Ireland, Britain and Channel Islands
• C. c. caeruleus – (Linnaeus, 1758): the nominate subspecies, occurring in Continental Europe to northern Spain, Sicily, northern Turkey and northern Urals
• C. c. balearicus – (von Jordans, 1913): native to Majorca Island (Balearic Islands)
• C. c. ogliastrae – (Hartert, 1905): found in Portugal, southern Spain, Corsica and Sardinia
• C. c. calamensis – (Parrot, 1908): found in southern Greece, Pelopónnisos, Cyclades, Crete and Rhodes
• C. c. orientalis – Zarudny & Loudon, 1905: found in southern European Russia (Volga River to central and southern Urals)
• C. c. satunini – Zarudny, 1908: found in the Crimean Peninsula, Caucasus, Transcaucasia and northwestern Iran to eastern Turkey
• C. c. raddei – Zarudny, 1908: found in northern Iran
• C. c. persicus – (Blanford, 1873): found in the Zagros Mountains

Pleske's tit (Cyanistes × pleskei) is a common interspecific hybrid between this species and the azure tit (Cyanistes cyanus), in western Russia. Such birds can look like azure, but with less white on the tail and a bit of yellow on the chest or like blue tit but with whiteish bottom.{{cite book |last1=Harrap | first1=Simon | last2=Quinn | first2=David (Illus.) |year=1996 | title=Tits, Nuthatches and Treecreepers | location=London | publisher=Christopher Helm; A & C Black | isbn=978-0-7136-3964-3 | pages=393–394 | url=https://archive.org/details/titsnuthatchestr0000harr/page/393/mode/1up | url-access=registration }}{{ cite journal | last=Ławicki | first=Ł. | date=2012 | title=Azure tits and hybrids Azure x European blue tit in Europe | journal=Dutch Birding | volume=34 | issue=4 | pages=219–231 | url=https://www.researchgate.net/publication/264914009 }}

The Eurasian blue tit is usually {{convert|10.5–12|cm|in|abbr=on}} long with a wingspan of {{convert|17.5–20|cm|in|abbr=on}} for both sexes, and weighs about {{convert|11|g|oz|abbr=on}}. A typical blue tit has an intensively 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. The bill is black, the legs bluish grey, and the irises dark brown. The sexes are similar and often indistinguishable to human eyes, but under ultraviolet light, males have a brighter blue crown. Juvenile birds are more yellowish and have fewer contrasting colors. They become similar to mature ones in September, although some parts of the wings are kept until May/June next year.{{Cite book |last=Svensson |first=Lars |title=Ptaki Europy i obszaru śródziemnomorskiego |last2=Stawarczyk |first2=Tadeusz |last3=Zetterström |first3=Dan |last4=Graszka-Petrykowski |first4=Dariusz |last5=Mullarney |first5=Killian |date=2023 |publisher=Multico Oficyna Wydawnicza |isbn=978-83-7763-647-3 |edition=Wydanie III, poprawione i zaktualizowane |series=Przewodnik Collinsa |location=Warszawa}}

Blue tits can also see in ultraviolet light, which is one of the ways they can distinguish whether the bird they're seeing is a male, female or juvenile.{{Cite journal |last=Korsten |first=Peter |last2=Vedder |first2=Oscar |last3=Szentirmai |first3=István |last4=Komdeur |first4=Jan |date=2007 |title=Absence of status signalling by structurally based ultraviolet plumage in wintering blue tits (Cyanistes caeruleus) |journal=Behavioral Ecology and Sociobiology |language=en |volume=61 |issue=12 |pages=1933–1943 |doi=10.1007/s00265-007-0433-z |issn=1432-0762|doi-access=free |hdl=10831/92791 |hdl-access=free }} A male's cap is more intensively blue than a female's or chick's.

File:Blue tit displaying aggresion during ringing.jpg]]

There are currently around 20 to 44 million pairs in Europe.

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.

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.{{cite book |last=Holden |first=Peter|date=2012 |title=RSPB Handbook Of British Birds |pages=262 |publisher=Christopher Helm |isbn=978-1-4081-2735-3}}

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 as it visits garden bird feeders. It swings beneath the holder, calling "tee, tee, tee" or a scolding "churr".

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.

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.{{cite journal | author1= Bambini, G. |author2= Schlicht, E. | author3= Kempenaers, B. | year=2019| title= Patterns of female nest attendance and male feeding throughout the incubation period in Blue Tits Cyanistes caeruleus | journal=Ibis| volume=161| pages= 50–65| doi= 10.1111/ibi.12614| issue=2| doi-access= free}} Although socially monogamous, blue tits regularly engage in extra-pair copulations with other individuals.{{Cite journal | last1=Arct | first1=A. | last2=Drobniak | first2=S.M. | last3=Mellinger | first3=S. | last4=Martyka | first4=R. | last5=Gustafsson | first5=L. | last6=Cichoń | first6=M. | date=2022 | title=Extra-pair paternity in Blue tits (Cyanistes caeruleus) depends on the combination of social partners' age | journal=Ibis | volume=164 | issue=2 | pages=388–395 | doi=10.1111/ibi.13022 | doi-access=free }}

Eggs are {{convert|14|–|18|mm|in|abbr=on}} long and {{convert|10.7|–|13.5|mm|abbr=on}} 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.File:Blue tit (Cyanistes caeruleus) juvenile.jpg, 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.{{Cite journal | last1=Janas | first1=K. | last2=Lutyk | first2=D. | last3=Sudyka | first3=J. | last4=Dubiec | first4=A. | last5=Gustafsson | first5=L. | last6=Cichoń | first6=M. | last7=Drobniak | first7=S. | date=2020 | title=Carotenoid-based coloration correlates with the hatching date of Blue tit Cyanistes caeruleus nestlings | journal=Ibis | volume=162 | issue=3 | pages=645–654 | doi=10.1111/ibi.12751}}

The bird is a close sitter, hissing and biting at an intruding finger. In the southwest of England, such behaviour has earned the Eurasian blue tit the colloquial nickname "Little Billy Biter" or "Billy Biter".{{cite book|url=https://books.google.com/books?id=aWonDwAAQBAJ&q=billy+biter+blue+tit&pg=PT332|title=The Blue Tit|first=Martyn|last=Stenning|date=22 February 2018|publisher=Bloomsbury Publishing|via=Google Books|isbn=9781472937391}} 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 eggs 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 feeding 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%. This implies that the typical life expectancy of a bird on reaching breeding age is three years. Within Britain, the maximum recorded age is 10 years and 3 months for a bird that was ringed in Bedfordshire. The maximum recorded age overall is 11 years and 7 months for a bird in the Czech Republic.

File:Cyanistes caeruleus -garden bird feeder-8.ogv in England]]

File:Eurasian blue tit - 2018.JPG

The Eurasian blue tit mainly feeds on insects, spiders and other small invertebrates but will eat fruits and seeds outside the breeding season. Animal items include springtails (Collembola), grasshoppers (Orthoptera), damselflies (Odonata), earwigs (Dermaptera), moths (Lepidoptera) and lacewings (Neuroptera). Items are often taken while hanging upside-down. When foraging it will probe into opening buds and peel bark from hazels (Corylus). It rarely hovers and only very occasionally forages on the ground. It visits bird tables and will take bread, cheese, fat and a variety of seeds, especially of sunflowers (Helianthus. Large seeds are taken to a nearby branch and opened by holding the seed with one foot while hammering it with the bill.{{sfn|Cramp|Perrins|1993|pp=229–235}}{{ cite book | last1=Gosler | first1=A.G. | last2=Clement | first2=P. | year=2007 | chapter=Family Paridae (Tits and Chickadees) | editor1-last=del Hoyo | editor1-first=J. | editor2-last=Elliott | editor2-first=A. | editor3-last=Sargatal | editor3-first=J. | title=Handbook of the Birds of the World | volume=12: Picathartes to Tits and Chickadees | location=Barcelona, Spain | publisher=Lynx Edicions | isbn=978-84-96553-42-2 | pages=662–750 [747-748] | chapter-url=https://archive.org/details/handbookofbirdso0012unse/page/747/mode/1up | chapter-url-access=registration }}

File:Blue Tit (Cyanistes caeruleus) (W1CDR0001535 BD30).ogg

Eurasian blue tits use songs and calls throughout the year.{{sfn|Cramp|Perrins|1993|p=239}} Songs are mostly used in late winter and spring to defend the territory or to attract mates. Calls are used for multiple reasons. Communication with other Eurasian blue tits is the most important motivation for the use of calls. They inform one another of 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. 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 '{{Not a typo|zeedling}}' notes are given by both partners before and during copulation. The begging-call is used by juveniles to beg for food from parents.

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. Such behaviour has since been gradually suppressed as a result of the declining popularity of both full-fat milk and milk delivery. 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.

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 Eurasian 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.

File:A bald blue tit with mite.jpg

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.

In Europe the long-term population trend of the Eurasian blue tit is positive with a 30 percent increase between 1980 and 2016. In the same period there was a {{cvt|500|km}} northward shift of the range limit in Fennoscandia. Laying dates have advanced and the warmer springs increase the possibility of second broods.{{Cite book | last1=Paquet | first1=J.-Y. | last2=Keller | first2=V. | editor1-last=Keller | chapter=Cyanistes caeruleus Eurasian blue tit | editor1-first=Verena | display-editors=etal | date=2020 | title=European Breeding Bird Atlas 2: Distribution, Abundance and Change | location=Barcelona | publisher=European Bird Census Council and Lynx Edicions | isbn=978-84-16728-38-1 | pages=580–581 }} The species is classified as a of least concern in the Red list of the International Union for Conservation of Nature, and as a Green Status species, since 1996, by the Royal Society for the Protection of Birds in the United Kingdom.

The Eurasian blue tit has appeared on many stamps and ornaments. Its most recent appearance on a British stamp was the 2025 "Garden Wildlife" series.{{cite web|url=https://shop.royalmail.com/subscriptions-and-gifts/presentation-packs-and-sets/garden-wildlife-presentation-pack|title=Garden Wildlife Presentation Pack|year=2025|work=royalmail.com|access-date=29 April 2025}}

{{Reflist|colwidth=30em|refs=

{{cite book |last1=Atyeo |first1=Warren T. |last2=Braasch |first2=Norman L. |title=The feather mite genus 'Proctophyllodes (Sarcoptiformes: Proctophyllodidae) |edition=1st |year=1966 |publisher=University of Nebraska |pages=1–351}}

{{cite web |url=https://www.bbc.co.uk/nature/life/Blue_Tit |title=Blue tit, Nature Wildlife |date=23 August 2011 |publisher=BBC |access-date=23 August 2011}}

{{cite journal |last1=Bijnens |first1=L. |last2=Dhondt |first2=A.A. |year=1984 |title=Vocalizations in a Belgian Blue Tit Parus c. caeruleus population |journal=Le Gerfaut |volume=74 |pages=243–269 |url=https://www.researchgate.net/publication/251879341}}

{{ cite web | title=Blue Tit Cyanistes caeruleus | url=https://www.bto.org/learn/about-birds/birdfacts/blue-tit | publisher=British Trust for Ornithology | access-date=9 June 2025 }}

{{cite web |first=Hazel |last=McCambridge |title=A Blue Tit diary |date=17 July 2019 |url=https://www.bto.org/understanding-birds/articles/blue-tit-diary |publisher=British Trust for Ornithology |access-date=26 May 2020}}

{{ cite web |last1=Fransson |first1=T. |last2=Kolehmainen |first2=T. |last3=Moss |first3=D. |last4=Robinson |first4=R. | year=2023 |title=EURING list of longevity records for European birds | url=https://www.euring.org/files/documents/EURING_longevity_list_20230901.pdf | publisher=European Union for Bird Ringing (EURING) | access-date=9 June 2025}}

{{cite book |last=Gesner |first=Conrad |author-link=Conrad Gesner |year=1555 |title=Historiæ animalium liber III qui est de auium natura. Adiecti sunt ab initio indices alphabetici decem super nominibus auium in totidem linguis diuersis: & ante illos enumeratio auium eo ordiné quo in hoc volumine continentur |publisher=Froschauer |location=Zurich |language=la |url=http://gdz.sub.uni-goettingen.de/en/dms/loader/img/?PID=PPN472755714&physid=PHYS_0650 |page=616}} NB –The link is to the preceding page.

{{cite journal |last1=Gill |first1=Frank B. |first2=Beth |last2=Slikas |author3-link=Fred Sheldon (ornithologist) |first3=Frederick H. |last3=Sheldon |year=2005 |title=Phylogeny of titmice (Paridae): II. Species relationships based on sequences of the mitochondrial cytochrome-b gene |journal=Auk |volume=122 |issue=1 |pages=121–143 |doi=10.1642/0004-8038(2005)122[0121:POTPIS]2.0.CO;2|s2cid=86067032 }}

{{cite book |title=Handbuch der Vögel Mitteleuropas |trans-title=Handbook of the Birds of Central Europe |language=de |volume=13/I |chapter=P. c. caeruleus |pages=581–587 |publisher=Aula |year=1993 |editor-first1=Kurt M. |editor-last1=Bauer |editor-first2=Urs Noel |editor-last2=Glutz von Blotzheim|title-link=Handbuch der Vögel Mitteleuropas }}

{{cite journal |last=Hinde |first=R.A. |year=1952 |title=The behaviour of the great tit (Parus major) and some other related species |journal=Behaviour. Supplement |issue=2 |pages=1–201 |jstor=30039125}}

{{cite web |url=http://maps.iucnredlist.org/map.html?id=22711944 |title=Parus caeruleus (Blue Tit) – Map |work=IUCN Red List of Threatened Species |publisher=International Union for Conservation of Nature |access-date=1 May 2014}}

{{cite book |last=Jobling |first=James A. |year=2010 |title=The Helm Dictionary of Scientific Bird Names |url=https://archive.org/details/Helm_Dictionary_of_Scientific_Bird_Names_by_James_A._Jobling |publisher=Christopher Helm |location=London |isbn=978-1-4081-2501-4 |pages=[https://archive.org/details/Helm_Dictionary_of_Scientific_Bird_Names_by_James_A._Jobling/page/n83 83], 293}}

{{cite journal |last1=Klump |first1=G.M. |last2=Curio |first2=E. |year=1983 |title=Reactions of Eurasian blue tits Parus caeruleus to hawk models of different sizes |journal=Bird Behavior |volume=4 |number=2 |pages=78–81 |url=http://www.ingentaconnect.com/contentone/cog/bb/1983/00000004/00000002/art00004;jsessionid=1vy6be451ybix.victoria}}

{{cite book |language=la |last=Linnaeus |first=C. |author-link=Carl Linnaeus |title=Systema naturae per regna tria naturae, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis. Tomus I. Editio decima, reformata. |volume=v.1 |location=Holmiae. [Stockholm] |publisher=(Laurentii Salvii). |year=1758 |quote=P. remigibus caerulescentibus : primoribus margine exteriore albis, fronte alba, vertice caeruleo. |pages=190 |url=https://www.biodiversitylibrary.org/page/727099 }}

{{cite news |url=https://www.independent.co.uk/environment/blue-tits-lose-their-bottle-as-milk-thieves-84526.html |title=Blue tits lose their bottle as milk thieves |last=McCarthy |first=Michael |date=31 December 2003 |work=The Independent |access-date=22 August 2011}}

{{cite journal |first=Jiří |last=Mlíkovský |journal=Zootaxa |issue=3005 |pages=45–68 |date=26 August 2011 |title=Nomenclatural and taxonomic status of bird taxa (Aves) described by an ornithological swindler, Josef Prokop Pražák (1870–1904) |volume=3005 |doi=10.11646/zootaxa.3005.1.2 }}

{{cite journal |last1=Hunt |first1=S. |first2=A.T.D. |last2=Bennett |first3=I.C. |last3=Cuthill |first4=R. |last4=Griffiths |title=Blue tits are ultraviolet tits |journal=Proceedings of the Royal Society B: Biological Sciences |date=1998 |publisher=Royal Society |doi=10.1098/rspb.1998.0316 |pmc=1688906 |volume=265 |issue=1395 |pages=451–455}}

{{cite journal |title=Birds take a fancy to putty |journal=New Scientist |date=24 October 1952 |access-date=6 May 2016 |url=https://books.google.com/books?id=mk6T6Txxn50C&pg=PA8 |page=8 |volume=2 |issue=49|last1=Information |first1=((Reed Business)) }}

{{cite web |last1=Robinson |first1=R.A. |last2=Leech |first2=D.I. |last3=Clark |first3=J.A. |title=Longevity records for Britain & Ireland in 2014 |publisher=British Trust for Ornithology |url=http://app.bto.org/ring/countyrec/results2014/longevity.htm#14620 |access-date=26 March 2016 |archive-url=https://web.archive.org/web/20170407123109/http://app.bto.org/ring/countyrec/results2014/longevity.htm#14620 |archive-date=7 April 2017 |url-status=dead }}

{{cite web |url=http://www.rspb.org.uk/wildlife/birdguide/name/b/bluetit/index.aspx |title=Blue Tit |date=23 August 2011 |publisher=RSPB |access-date=23 August 2011}}

{{cite journal |last=Sasvári |first=Lajos |date=August 1979 |title=Observational learning in great, blue and marsh tits |journal=Animal Behaviour |volume=27 |issue=3 |pages=767–771 |doi=10.1016/0003-3472(79)90012-5|s2cid=53150665 }}

{{cite journal |last1=Siriwardena |first1=G.M. |last2=Baillie |first2=S.R. |last3=Wilson |first3=J.D. |year=1998 |title=Variation in the survival rates of some British passerines with respect to their population trends on farmland |journal=Bird Study |volume=45 |issue=3 |pages=1998 |doi=10.1080/00063659809461099 |doi-access=free }}

}}

{{refbegin}}

• {{ cite book | editor1-last=Cramp | editor1-first=Stanley | editor1-link=Stanley Cramp | editor2-last=Perrins | editor2-first=C.M. | year=1993 | chapter=Parus caeruleus Blue tit | title=Handbook of the Birds of Europe the Middle East and North Africa. The Birds of the Western Palearctic | volume=VII: Flycatchers to Strikes | location=Oxford | publisher=Oxford University Press | pages=225–248 | isbn=978-0-19-857510-8 }}

{{refend}}

{{Commons}}

• {{cite web |last1=Blasco-Zumeta |first1=Javier |last2=Heinze |first2=Gerd-Michael |title=Blue Tit: Aging and sexing |url=http://aulaenred.ibercaja.es/wp-content/uploads/393_BlueTitPcaeruleus.pdf |publisher=Laboratorio Virtual Ibercaja |access-date=2014-11-24 |archive-url=https://web.archive.org/web/20160314193752/http://aulaenred.ibercaja.es/wp-content/uploads/393_BlueTitPcaeruleus.pdf |archive-date=2016-03-14 |url-status=dead | ref=none}}
• [http://www.ornithos.de/Ornithos/Feather_Collection/Parus_caeruleus/Parus_caeruleus.htm Feathers of Eurasian blue tit (Parus caeruleus)] {{Webarchive|url=https://web.archive.org/web/20141201062350/http://www.ornithos.de/Ornithos/Feather_Collection/Parus_caeruleus/Parus_caeruleus.htm |date=2014-12-01 }}
• {{BirdLife|103761667|Cyanistes caeruleus}}
• {{InternetBirdCollection|common-blue-tit-cyanistes-caeruleus|Common blue tit}}
• {{VIREO|blue+tit}}
• {{field guide birds of the world|Cyanistes caeruleus}}
• {{ARKive}}
• [https://www.youtube.com/watch?v=ldUf6fD0NzI Blue tit improving the hollow entrance]

{{Taxonbar|from=Q25404}}

{{Authority control}}

Category:Articles containing video clips

Category:Birds described in 1758

Category:Birds of Europe

Category:Cyanistes

Category:Taxa named by Carl Linnaeus