The Blue Tit (Cyanistes caeruleus[2] or Parus caeruleus[3]) is a 10.5 to 12 cm (4.2 to 4.8 inches) long passerine bird in the tit family Paridae. It is a widespread and common resident breeder throughout temperate and subarctic Europe and western Asia in deciduous or mixed woodlands. It is a resident bird; i.e., most tits do not migrate.

Taxonomy

This species was first described by Linnaeus in his Systema naturae in 1758 as Parus caeruleus.[4]

Most authorities retain Cyanistes as a subgenus of Parus, but the British Ornithologists' Union treats Cyanistes as a distinct genus. This is supported by mtDNA cytochrome b sequence analysis which suggests that Cyanistes is not only distinct, but not close to other tits (Gill et al., 2005).

Subspecies An adult Canary Islands Blue Tit on Gran Canaria, Spain. Its crown is black.

The systematics of the Blue Tit complex are disputed. There are currently at least nine recognised subspecies:[5]

• C. c. caeruleus (Linnaeus, 1758), the nominate subspecies, occurring in Continental Europe to n Spain, Sicily, n Turkey and n Urals
• C. c. obscurus (Pra?ák, 1894), Ireland, Britain and Channel Islands[6]
• C. c. ogilastrae (Hartert, 1905), Portugal, s Spain, Corsica and Sardinia
• C. c. balearicus (von Jordans, 1913), Majorca Island (Balearic Islands)
• C. c. calamensis (Parrot, 1908), s Greece, Pelopónnisos, Cyclades, Crete and Rhodes
• C. c. orientalis (Zarudny & Loudon, 1905), s European Russia (Volga River to central and s Urals)
• C. c. satunini (Zarudny, 1908), Crimean Peninsula, Caucasus, Transcaucasia and nw Iran to e Turkey
• C. c. raddei (Zarudny, 1908), N Iran
• C. c. persicus (Blanford, 1873), Zagros Mountains

The two traditional subspecies found in the Canary Islands (teneriffae) and northwest Africa from northern Morocco to northern Libya (ultramarinus) are distinctive. The Canary Islands subspecies has a black cap, and the African form has a blue back. Research is underway to split these populations into distinct species, with a peculiar "leapfrog" distribution (Kvist et al., 2005; Kvist, 2006; Sangster, 2006):

• Afrocanarian Blue Tit or Ultramarine Tit, Parus ultramarinus Bonaparte, 1841 (La Palma, Hierro, Fuerteventura, Lanzarote, NW Africa) updated to species status in 2010
• Canary Islands Blue Tit, Parus teneriffae Lesson, 1831 (Tenerife, La Gomera, Gran Canaria)

The former would contain three or four subspecies (palmensis, ombriosus and ultramarinus/degener), the latter the nominate P. t. teneriffae and the unnamed distinct form of Gran Canaria.

Hybrids

Pleske's Tit (Cyanistes × pleskei) is a not uncommon hybrid between this species and the Azure Tit in western Russia.

Description With food for its chicks in France

The blue tit is usually 12 centimetres (4.7 in) long with a wingspan of 18 centimetres (7.1 in) for all genders, and weighs about 11 grams (0.39 oz).[7]

The common 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; the back is yellowish green; the under parts mostly sulphur-yellow with a dark line down the abdomen. The bill is black, the legs bluish grey, and the irides dark brown. The sexes are similar, but under ultraviolet light, males have a brighter blue crown. Young Blue Tits are noticeably more yellow.

The yellowness of the tummy is indicative of the number of yellowy-green caterpillars eaten, due to high levels of carotene pigments in the diet.[8]

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".

Population and Distribution

There are currently 20-44 million pairs in Europe.[9]

The Blue Tit and the related hybrids are considered native species in areas of the European continent with mainly temperate or Mediterranean climate (except Iceland and Malta) and parts of the Middle East and North Africa.[1]

Lifespan

The Blue Tit has an average life expectancy of one-and-a-half to three years.[7][10] The longest recorded lifespans by country for the species are: 9 years 9 months 2 days in the United Kingdom,[11] and 11 years 7 months in the Czech Republic.[12]

Breeding Feeding the young at a nest box in England

It 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.[9]

The bird is a close sitter, hissing and biting at an intruding finger. In the South West of England such behaviour has earned the Blue Tit the colloquial nickname "Little Billy Biter".[by whom?] 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, and bigger clutches are usually laid by two or even more hens. It is not unusual for a single bird to feed the chicks in the nest at a rate of one feed every ninety (90) seconds during the height of the breeding season. Its colourful mix of blue, yellow, white and green make the blue tit one of the most attractive resident garden birds. Almost any garden with a peanut feeder will attract them and they readily breed in nest boxes. In winter they form flocks with other tit species and a garden with four or five at a bird table at any one time, may be feeding 20 or more at the same time.

Behaviour

Blue and Great Tits form mixed winter flocks, and the former are perhaps the better gymnasts in the slender twigs. A Blue Tit will often ascend a trunk in short jerky hops, imitating a Treecreeper. As a rule the bird roosts in ivy or evergreens, but in harsh winters will nest wherever there is a suitable small hole, be it in a tree or nesting box. Blue tits are very agile and can hang from almost anywhere.

Diet Eating peanuts from a garden bird feeder in England

The Blue Tit is a valuable destroyer of pests, though it has not an entirely clean sheet as a beneficial species. It is fond of young buds of various trees, and may pull them to bits in the hope of finding insects. No species, however, destroys more coccids and aphids, the worst foes of many plants. It takes leaf miner grubs and green tortrix moths (Tortricidae). Seeds are eaten, as with all this family.

Voice

Blue Tits use songs and calls throughout the year.[13] Songs are a mostly used in late winter and spring to defend the territory or to attract mates. Calls are used for multiple reasons.[14] Communication with other 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.[15] 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.[16] The begging-call is used by juveniles to beg for food from parents.

Learning

Blue Tits are able to culturally transmit learning to other Tit species. An example of this, dating from the 1920s, is the ability to open milk bottles with foil tops, to get at the cream underneath.[17] 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, instead of the milkman).[18]

Predators This section requires expansion.

The small size of the blue tit makes it vulnerable to prey by larger birds such as Jays who catch the vulnerable fledglings when leaving the nest. The most important predator is probably the sparrowhawk. Nests may be robbed by mammals such as weasels and red squirrels and grey squirrels in the UK.

Natural threats

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,[19] particularly if this coincides with the emergence of the caterpillars on which the nestlings are fed.

Parasites

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. P. stylifer however 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 developemental 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.[20]

Conservation

The 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.[7][9]

Citations and references

Citations

1. ^ a b c BirdLife International (2009). "Parus caeruleus". IUCN Red List of Threatened Species. Version 2011.1. International Union for Conservation of Nature. http://www.iucnredlist.org/apps/redlist/details/147892. Retrieved 13 August 2011. 
2. ^ Wright, Gill, Frank and Minturn (2006). Birds of the World: Recommended English Names (1 ed.). Princeton University Press. pp. ix + 259. ISBN 0-691-12827-8. 
3. ^ Howard, Richard; Moore, Alick (2003). Edward Dickinson. ed. The Howard and Moore Complete Checklist of the Birds of the World (3rd ed.). Christopher Helm. ISBN 0-7136-6536-X. 
4. ^ (Latin) Linnaeus, C (1758). Systema naturae per regna tria naturae, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis. Tomus I. Editio decima, reformata.. Holmiae. (Laurentii Salvii).. pp. 190. "P. remigibus caerulescentibus : primoribus margine exteriore albis, fronte alba, vertice caeruleo." 
5. ^ Clements, James (2011). The Clements Checklist of Birds of the World (6th ed.). Cornell University Press. ISBN 0713686952. 
6. ^ Mlíkovský, Ji?í (26 August 2011). "Nomenclatural and taxonomic status of bird taxa (Aves) described by an ornithological swindler, Josef Prokop Pra?ák (1870"?1904)". Zootaxa (3005): 45"?68. 
7. ^ a b c "Blue Tit (Cyanistes caeruleus)". British Trust for Ornithology. 8 December 2010. http://blx1.bto.org/birdfacts/results/bob14620.htm. Retrieved 23 August 2011. 
8. ^ "Blue tit, Nature Wildlife". BBC. 23 August 2011. http://www.bbc.co.uk/nature/life/Blue_Tit. Retrieved 23 August 2011. 
9. ^ a b c "Blue Tit". RSPB. 23 August 2011. http://www.rspb.org.uk/wildlife/birdguide/name/b/bluetit/index.aspx. Retrieved 23 August 2011. 
10. ^ "Life Expectancy". British Garden Birds. David Gains. http://www.garden-birds.co.uk/information/lifespan.htm. Retrieved 24 January 2007. 
11. ^ "Longevity records for Britain & Ireland in 2009". British Trust for Ornithology. 9 Dezember 2010. http://blx1.bto.org/ring/countyrec/results2009/longevity.htm. Retrieved 23 August 2011. 
12. ^ "European Longevity Records". European Union for Bird Ringing (EURING). 26 November 2010. http://www.euring.org/data_and_codes/longevity-voous.htm. Retrieved 23 August 2011. 
13. ^ Cramp S, Perrins CMP et al(1993). Handbook of the Birds of Europe the Middle East and North Africa - The Birds of the Western Palearctic Volume VII. Oxford University Press, Oxford, New York 1993
14. ^ Bijnens L and Dhondt AA (1984). Vocalizations in a Belgian Blue Tit Parus c. caeruleus population. Gerfault 74, 243-69
15. ^ Klump GM and Curio E (1983). Reactions of Blue Tits Parus caeruleus to Hawk Models of Different Sizes. Bird Behavior 4, 78-81
16. ^ Hinde, RA (1952). The behaviour of the Great Tit (Parus Major) and some other related species. Behaviour (Suppl.) II: 1-201.
17. ^ Sasvári, Lajos (August 1979). "Observational learning in great, blue and marsh tits". Animal Behaviour 27 (3): 767"?771. doi:10.1016/0003-3472(79)90012-5. 
18. ^ McCarthy, Michael (31 December 2003). "Blue tits lose their bottle as milk thieves". The Independent. http://www.independent.co.uk/environment/blue-tits-lose-their-bottle-as-milk-thieves-578134.html. Retrieved 22 August 2011. 
19. ^ Derbyshire, David (5 November 2007). "Disappearing blue tits pay the price of soggy summer". The Daily Mail (Associated Newspapers). http://www.dailymail.co.uk/news/article-491903/Disappearing-blue-tits-pay-price-soggy-summer.html. Retrieved 23 August 2011. 
20. ^ Braasch, Norman, L (1966). The feather mite genus 'Proctophyllodes (Sarcoptiformes: Proctophyllodidae) (1 ed.). University of Nebraska. pp. 1"?351. 

References

• Gill, Frank B.; Beth Slikas and Frederick H. Sheldon (2005). "Phylogeny of titmice (Paridae): II. Species relationships based on sequences of the mitochondrial cytochrome-b gene.". Auk 122 (1): 121"?143. doi:10.1642/0004-8038(2005)122[0121:POTPIS]2.0.CO;2.  DOI: 10.1642/0004-8038(2005)122[0121:POTPIS]2.0.CO;2 HTML abstract

• Kvist, Laura (2006). "Response to "Taxonomic status of 'phylogroups' in the Parus teneriffae complex (Aves)" by George Sangster". Molecular Phylogenetics and Evolution 38 (1): 290. doi:10.1016/j.ympev.2005.10.012.  (HTML abstract)

• Kvist, Laura; J. Broggi, J.C Illera, and K. Koivula (2005). "Colonisation and diversification of the blue tits (Parus caeruleus teneriffae-group) in the Canary Islands". Molecular Phylogenetics and Evolution 34 (3): 501"?511. doi:10.1016/j.ympev.2004.11.017. PMID 15683925.  (HTML abstract)

• Sangster, George (2006). "c status of "phylogroups" in the Parus teneriffae complex (Aves): Comments on the paper by Kvist et al. (2005). Molecular Phylogenetics and Evolution". Molecular phylogenetics and evolution 38 (1): 288"?289. doi:10.1016/j.ympev.2005.10.009. PMID 16314112.  (HTML abstract)

External links Wikimedia Commons has media related to: Parus caeruleus

• The Royal Society for the Protection of Birds (Blue Tit)
• Blue Tit videos, photos & sounds on the Internet Bird Collection.