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Subspecies |
The dark juveniles typical of these island forms are occasionally found in mainland Scotland and elsewhere , indicating some gene flow from faroensis or zetlandicus , subspecies formerly considered to be isolated . Birds from Fair Isle , St Kilda and the Outer Hebrides are intermediate in size between S. v. zetlandicus and the nominate form , and their subspecies placement varies according to the authority . |
Several other subspecies have been named , but are generally no longer considered valid . Most are intergrades that occur where the ranges of various subspecies meet . S. v. persepolis Ticehurst , 1928 from southern Iran 's ( Fars Province ) is very similar to S. v. vulgaris , and it is not clear whether it is a distinct resident population or simply migrants from southeastern Europe . These include : S. v. ruthenus Menzbier , 1891 and S. v. jitkowi Buturlin , 1904 , which are intergrades between vulgaris and poltaratskyi from western Russia ; S. v. graecus Tschusi , 1905 and S. v. balcanicus Buturlin and Harms , 1909 , intergrades between vulgaris and tauricus from the southern Balkans to central Ukraine and throughout Greece to the Bosporus ; and S. v. heinrichi Stresemann , 1928 , an intergrade between caucasicus and nobilior in northern Iran . |
= = Description = = |
The legs are stout and pinkish- or greyish @-@ red . @ 6 oz ) . @ 5 to 3 @. @ 3 in ) . @ 8 to 13 @. @ 8 to 6 @. In flight , its strongly pointed wings and dark colouration are distinctive , while on the ground its strange , somewhat waddling gait is also characteristic . @ 8 cm ( 2 @. @ 3 to 2 @. They can usually be sexed by the colour of the irises , rich brown in males , mouse @-@ brown or grey in females . @ 26 in ) and the tarsus is 2 @. The colouring and build usually distinguish this bird from other starlings , although the closely related spotless starling may be physically distinguished by the lack of iridescent spots in adult breeding plumage . @ 4 in ) , the tail is 5 @. The common starling is 19 – 23 cm ( 7 @. @ 98 to 1 @. @ 0 – 3 @. @ 6 to 5 @. The throat feathers of males are long and loose and are used in display while those of females are smaller and more pointed . The common starling is mid @-@ sized by both starling standards and passerine standards . @ 2 cm ( 0 @. Moulting occurs once a year- in late summer after the breeding season has finished ; the fresh feathers are prominently tipped white ( breast feathers ) or buff ( wing and back feathers ) , which gives the bird a speckled appearance . It is readily distinguished from other mid @-@ sized passerines , such as thrushes , icterids or small corvids , by its relatively short tail , sharp , blade @-@ like bill , round @-@ bellied shape and strong , sizeable ( and rufous @-@ coloured ) legs . The underparts of adult male common starlings are less spotted than those of adult females at a given time of year . The plumage is iridescent black , glossed purple or green , and spangled with white , especially in winter . Juveniles are grey @-@ brown and by their first winter resemble adults though often retaining some brown juvenile feathering , especially on the head . @ 8 cm ( 4 @. @ 2 cm ( 1 @. Among standard measurements , the wing chord is 11 @. The bill is narrow and conical with a sharp tip ; in the winter it is brownish @-@ black but in summer , females have lemon yellow beaks while males have yellow bills with blue @-@ grey bases . Estimating the contrast between an iris and the central always @-@ dark pupil is 97 % accurate in determining sex , rising to 98 % if the length of the throat feathers is also considered . @ 7 in ) , the culmen is 2 @. @ 1 to 1 @. @ 1 in ) long , with a wingspan of 31 – 44 cm ( 12 – 17 in ) and a weight of 58 – 101 g ( 2 @. @ 7 to 3 @. @ 5 – 9 @. The reduction in the spotting in the breeding season is achieved through the white feather tips largely wearing off . |
Like most terrestrial starlings the common starling moves by walking or running , rather than hopping . Common starling on migration can fly at 60 – 80 km / h ( 37 – 50 mph ) and cover up to 1 @,@ 000 – 1 @,@ 500 km ( 620 – 930 mi ) . Their flight is quite strong and direct ; their triangular @-@ shaped wings beat very rapidly , and periodically the birds glide for a short way without losing much height before resuming powered flight . When in a flock , the birds take off almost simultaneously , wheel and turn in unison , form a compact mass or trail off into a wispy stream , bunch up again and land in a coordinated fashion . |
Several terrestrial starlings , including those in the genus Sturnus , have adaptations of the skull and muscles that help with feeding by probing . This adaptation is most strongly developed in the common starling ( along with the spotless and white @-@ cheeked starlings ) , where the protractor muscles responsible for opening the jaw are enlarged and the skull is narrow , allowing the eye to be moved forward to peer down the length of the bill . This technique involves inserting the bill into the ground and opening it as a way of searching for hidden food items . Common starlings have the physical traits that enable them to use this feeding technique , which has undoubtedly helped the species spread far and wide . |
At close range it can be seen that the latter has longer throat feathers , a fact particularly noticeable when it sings . In Iberia , the western Mediterranean and northwest Africa , the common starling may be confused with the closely related spotless starling , the plumage of which , as its name implies , has a more uniform colour . |
= = = Voice = = = |
Each bird has its own repertoire with more proficient birds having a range of up to 35 variable song types and as many as 14 types of clicks . The structure and simplicity of the sound mimicked is of greater importance than the frequency with which it occurs . The male is the main songster and engages in bouts of song lasting for a minute or more . Each of these typically includes four varieties of song type , which follow each other in a regular order without pause . The bout starts with a series of pure @-@ tone whistles and these are followed by the main part of the song , a number of variable sequences that often incorporate snatches of song mimicked from other species of bird and various naturally occurring or man @-@ made noises . Its song consists of a wide variety of both melodic and mechanical @-@ sounding noises as part of a ritual succession of sounds . After this variable section comes a number of types of repeated clicks followed by a final burst of high @-@ frequency song , again formed of several types . Each sound clip is repeated several times before the bird moves on to the next . The common starling is a noisy bird . |
In the presence of a female , a male sometimes flies to his nest and sings from the entrance , apparently attempting to entice the female in . Having a complex song is also useful in defending a territory and deterring less experienced males from encroaching . Males sing constantly as the breeding period approaches and perform less often once pairs have bonded . Older birds tend to have a wider repertoire than younger ones . Those males that engage in longer bouts of singing and that have wider repertoires attract mates earlier and have greater reproductive success than others . Females appear to prefer mates with more complex songs , perhaps because this indicates greater experience or longevity . |
The songsters are more commonly male although females also sing on occasion . Eleven other types of call have been described including a flock call , threat call , attack call , snarl call and copulation call . Singing also occurs outside the breeding season , taking place throughout the year apart from the moulting period . The function of such out @-@ of @-@ season song is poorly understood . When a flock of common starlings is flying together , the synchronised movements of the birds ' wings make a distinctive whooshing sound that can be heard hundreds of metres ( yards ) away . They chatter while roosting and bathing , making a great deal of noise that can cause irritation to people living nearby . The alarm call is a harsh scream , and while foraging together common starlings squabble incessantly . |
= = Behaviour and ecology = = |
These may accumulate up to 30 cm ( 12 in ) deep , killing trees by their concentration of chemicals . These dense concentrations of birds are thought to be a defence against attacks by birds of prey such as peregrine falcons or Eurasian sparrowhawks . Flocks form a tight sphere @-@ like formation in flight , frequently expanding and contracting and changing shape , seemingly without any sort of leader . In smaller amounts , the droppings act as a fertiliser , and therefore woodland managers may try to move roosts from one area of a wood to another to benefit from the soil enhancement and avoid large toxic deposits . Very large roosts , exceptionally up to 1 @. The common starling is a highly gregarious species , especially in autumn and winter . @ 5 million birds , can form in city centres , woodlands or reedbeds , causing problems with their droppings . Although flock size is highly variable , huge , noisy flocks - murmurations - may form near roosts . Each common starling changes its course and speed as a result of the movement of its closest neighbours . |
They gather in March until northern Scandinavian birds leave for their breeding ranges by mid @-@ April . These flocks are commonly called murmurations . Huge flocks of more than a million common starlings may be observed just before sunset in spring in southwestern Jutland , Denmark over the seaward marshlands of Tønder and Esbjerg municipalities between Tønder and Ribe . Their swarm behaviour creates complex shapes silhouetted against the sky , a phenomenon known locally as sort sol ( " black sun " ) . Flocks of anything from five to fifty thousand common starlings form in areas of the UK just before sundown during mid @-@ winter . |
= = = Feeding = = = |
The food range includes spiders , crane flies , moths , mayflies , dragonflies , damsel flies , grasshoppers , earwigs , lacewings , caddisflies , flies , beetles , sawflies , bees , wasps and ants . The Sturnidae differ from most birds in that they cannot easily metabolise foods containing high levels of sucrose , although they can cope with other fruits such as grapes and cherries . While the consumption of invertebrates is necessary for successful breeding , common starlings are omnivorous and can also eat grains , seeds , fruits , nectar and food waste if the opportunity arises . The isolated Azores subspecies of the common starling eats the eggs of the endangered roseate tern . Measures are being introduced to reduce common starling populations by culling before the terns return to their breeding colonies in spring . Both adults and larvae are consumed and common starlings will also feed on earthworms , snails , small amphibians and lizards . The common starling is largely insectivorous and feeds on both pest and other arthropods . |
The larger the flock , the nearer individuals are to one another while foraging . Generally , common starlings prefer foraging amongst short @-@ cropped grasses and are often found among grazing animals or perched on their backs , where they will also feed on the mammal 's external parasites . Flocks often feed in one place for some time , and return to previous successfully foraged sites . There are several methods by which common starlings obtain their food but for the most part , they forage close to the ground , taking insects from the surface or just underneath . Large flocks may engage in a practice known as " roller @-@ feeding " , where the birds at the back of the flock continually fly to the front where the feeding opportunities are best . |
Hawking " is the capture of flying insects directly from the air , and " lunging " is the less common technique of striking forward to catch a moving invertebrate on the ground . This behaviour , first described by Konrad Lorenz and given the German term zirkeln , is also used to create and widen holes in plastic garbage bags . Common starlings that have periods without access to food , or have a reduction in the hours of light available for feeding , compensate by increasing their body mass by the deposition of fat . It takes time for young common starlings to perfect this technique , and because of this the diet of young birds will often contain fewer insects . " Earthworms are caught by pulling from soil . There are three types of foraging behaviour observed in the common starling . " Probing " involves the bird plunging its beak into the ground randomly and repetitively until an insect has been found , and is often accompanied by bill gaping where the bird opens its beak in the soil to enlarge a hole . |
= = = Nesting = = = |
The scent of plants such as yarrow acts as an olfactory attractant to females . Unpaired males find a suitable cavity and begin to build nests in order to attract single females , often decorating the nest with ornaments such as flowers and fresh green material , which the female later disassembles upon accepting him as a mate . The amount of green material is not important , as long as some is present , but the presence of herbs in the decorative material appears to be significant in attracting a mate . |
S. v. zetlandicus typically breeds in crevices and holes in cliffs , a habitat only rarely used by the nominate form . The males sing throughout much of the construction and even more so when a female approaches his nest . Nests may be in any type of hole , common locations include inside hollowed trees , buildings , tree stumps and man @-@ made nest @-@ boxes . Following copulation , the male and female continue to build the nest . Construction usually takes four or five days and may continue through incubation . Nests are typically made out of straw , dry grass and twigs with an inner lining made up of feathers , wool and soft leaves . |
Males may mate with a second female while the first is still on the nest . Pairs may be part of a colony , in which case several other nests may occupy the same or nearby trees . Common starlings are both monogamous and polygamous ; although broods are generally brought up by one male and one female , occasionally the pair may have an extra helper . The reproductive success of the bird is poorer in the second nest than it is in the primary nest and is better when the male remains monogamous . |
= = = Breeding = = = |
There are normally four or five eggs that are ovoid in shape and pale blue or occasionally white , and they commonly have a glossy appearance . @ 5 – 34 @. @ 36 in ) in length and 20 @. @ 89 in ) in maximum diameter . If an egg is lost during this time , she will lay another to replace it . @ 0 – 22 @. The egg size is 26 @. @ 5 mm ( 0 @. The colour of the eggs seems to have evolved through the relatively good visibility of blue at low light levels . Following copulation , the female lays eggs on a daily basis over a period of several days . @ 79 – 0 @. Breeding takes place during the spring and summer . @ 04 – 1 @. @ 5 mm ( 1 @. |
Within two months , most juveniles will have moulted and gained their first basic plumage . As with other passerines , the nest is kept clean and the chicks ' faecal sacs are removed by the adults . Nestlings remain in the nest for three weeks , where they are fed continuously by both parents . Fledglings continue to be fed by their parents for another one or two weeks . The young are born blind and naked . They develop light fluffy down within seven days of hatching and can see within nine days . Once the chicks are able to regulate their body temperature , about six days after hatching , the adults largely cease removing droppings from the nest . Both parents share the responsibility of brooding the eggs , but the female spends more time incubating them than does the male , and is the only parent to do so at night when the male returns to the communal roost . A pair can raise up to three broods per year , frequently reusing and relining the same nest , although two broods is typical , or just one north of 48oN . They acquire their adult plumage the following year . Incubation lasts thirteen days , although the last egg laid may take 24 hours longer than the first to hatch . Prior to that , the fouling would wet both the chicks ' plumage and the nest material , thereby reducing their effectiveness as insulation and increasing the risk of chilling the hatchlings . |
Female " floaters " ( unpaired females during the breeding season ) present in colonies often lay eggs in another pair 's nest . Intraspecific brood parasites are common in common starling nests . Fledglings have also been reported to invade their own or neighbouring nests and evict a new brood . Common starling nests have a 48 % to 79 % rate of successful fledging , although only 20 % of nestlings survive to breeding age ; the adult survival rate is closer to 60 % . The average life span is about 2 – 3 years , with a longevity record of 22 yr 11 m . |
= = Predators and parasites = = |
A majority of starling predators are avian . Their abilities in flight are seldom matched by birds of prey . The typical response of starling groups is to take flight , with a common sight being undulating flocks of starling flying high in quick and agile patterns . Adult common starlings are hunted by hawks such as the northern goshawk ( Accipiter gentilis ) and Eurasian sparrowhawk ( Accipiter nisus ) , and falcons including the peregrine falcon ( Falco peregrinus ) , Eurasian hobby ( Falco subbuteo ) and common kestrel ( Falco tinnunculus ) . While perched in groups by night , they can be vulnerable to owls , including the little owl ( Athene noctua ) , long @-@ eared owl ( Asio otus ) , short @-@ eared owl ( Asio flammeus ) , barn owl ( Tyto alba ) , tawny owl ( Strix aluco ) and Eurasian eagle @-@ owl ( Bubo bubo ) . Slower raptors like black and red kites ( Milvus migrans & milvus ) , eastern imperial eagle ( Aquila heliaca ) , common buzzard ( Buteo buteo ) and Australasian harrier ( Circus approximans ) tend to take the more easily caught fledglings or juveniles . |
More than twenty species of hawk , owl and falcon are known to occasionally predate feral starlings in North America , though the most regular predators of adults are likely to be urban @-@ living peregrine falcons or merlins ( Falco columbarius ) . Common mynas ( Acridotheres tristis ) sometimes evict eggs , nestlings and adult common starlings from their nests , and the lesser honeyguide ( Indicator minor ) , a brood parasite , uses the common starling as a host . Nests can be raided by animals capable of climbing to them , such as stoats ( Mustela erminea ) , raccoons ( Procyon lotor ) and squirrels ( Sciurus spp . ) Starlings are more commonly the culprits rather than victims of nest eviction however , especially towards other starlings and woodpeckers . , and cats may catch the unwary . |
A survey of three hundred common starlings from six US states found that all had at least one type of parasite ; 99 % had external fleas , mites or ticks , and 95 % carried internal parasites , mostly various types of worm . Blood @-@ sucking species leave their host when it dies , but other external parasites stay on the corpse . Common starlings are hosts to a wide range of parasites . A bird with a deformed bill was heavily infested with Mallophaga lice , presumably due to its inability to remove vermin . |
The small , pale house @-@ sparrow flea C. fringillae , is also occasionally found there and probably arises from the habit of its main host of taking over the nests of other species . Lice include Menacanthus eurystemus , Brueelia nebulosa and Stumidoecus sturni . The presence of this control on numbers of the parasitic species may explain why birds are prepared to reuse old nests . The hen mite D. gallinae is itself preyed upon by the predatory mite Androlaelaps casalis . This flea does not occur in the US , even on house sparrows . The hen flea ( Ceratophyllus gallinae ) is the most common flea in their nests . Other arthropod parasites include Ixodes ticks and mites such as Analgopsis passerinus , Boydaia stumi , Dermanyssus gallinae , Ornithonyssus bursa , O. sylviarum , Proctophyllodes species , Pteronyssoides truncatus and Trouessartia rosteri . |
Other recorded internal parasites include the spiny @-@ headed worm Prosthorhynchus transverses . The latter species breaks off the feathers of its host and lives on the fats produced by growing plumage . Protozoan blood parasites of the genus Haemoproteus have been found in common starlings , but a better known pest is the brilliant scarlet nematode Syngamus trachea . Larvae of the moth Hofmannophila pseudospretella are nest scavengers , which feed on animal material such as faeces or dead nestlings . This worm moves from the lungs to the trachea and may cause its host to suffocate . In Britain , the rook and the common starling are the most infested wild birds . Flying insects that parasitise common starlings include the louse @-@ fly Omithomya nigricornis and the saprophagous fly Camus hemapterus . |
Captive starlings often accumulate excess iron in the liver , a condition that can be prevented by adding black tea @-@ leaves to the food . Common starlings may contract avian tuberculosis , avian malaria and retrovirus @-@ induced lymphomas . |
= = Distribution and habitat = = |
The global population of common starlings was estimated to be 310 million individuals in 2004 , occupying a total area of 8 @,@ 870 @,@ 000 km2 ( 3 @,@ 420 @,@ 000 sq mi ) . Widespread throughout the Northern Hemisphere , the bird is native to Eurasia and is found throughout Europe , northern Africa ( from Morocco to Egypt ) , India ( mainly in the north but regularly extending further south and extending into the Maldives ) Nepal , the Middle East including Syria , Iran , and Iraq and north @-@ western China . |
Large numbers of birds from northern Europe , Russia and Ukraine migrate south westwards or south eastwards . Small numbers of common starling have sporadically been observed in Japan and Hong Kong but it is unclear from where these birds originated . Other groups of birds are in passage across the country and the pathways of these different streams of bird may cross . In the autumn , when immigrants are arriving from eastern Europe , many of Britain 's common starlings are setting off for Iberia and North Africa . Common starlings in the south and west of Europe and south of latitude 40oN are mainly resident , although other populations migrate from regions where the winter is harsh , the ground frozen and food scarce . Birds in the east of the country move southwards , and those from further west winter in the southwest of the US . Of the 15 @,@ 000 birds ringed as nestlings in Merseyside , England , individuals have been recovered at various times of year as far afield as Norway , Sweden , Finland , Russia , Ukraine , Poland , Germany and the Low Countries . In North America , northern populations have developed a migration pattern , vacating much of Canada in winter . |
rainforests or wet sclerophyll forests ) but are found in coastal areas , where they nest and roost on cliffs and forage amongst seaweed . Reedbeds are also favoured for roosting and the birds commonly feed in grassy areas such as farmland , grazing pastures , playing fields , golf courses and airfields where short grass makes foraging easy . Their ability to adapt to a large variety of habitats has allowed them to disperse and establish themselves in diverse locations around the world resulting in a habitat range from coastal wetlands to alpine forests , from sea cliffs to mountain ranges 1 @,@ 900 m ( 6 @,@ 200 ft ) above sea level . They occasionally inhabit open forests and woodlands and are sometimes found in shrubby areas such as Australian heathland . Common starlings rarely inhabit dense , wet forests ( i.e. Common starlings prefer urban or suburban areas where artificial structures and trees provide adequate nesting and roosting sites . |
= = = Introduced populations = = = |
As a result , it has also been able to migrate to Thailand , Southeast Asia and New Guinea . The common starling has been introduced to and has successfully established itself in New Zealand , Australia , South Africa , North America , Fiji and several Caribbean islands . |
= = = = South America = = = = |
In 1987 , a small population of common starlings was observed nesting in gardens in the city of Buenos Aires . @ 5 km ( 4 @. In Argentina , the species makes use of a variety of natural and man @-@ made nesting sites , particularly woodpecker holes . Five individuals conveyed on a ship from England alighted near Lago de Maracaibo in Venezuela in November 1949 , but subsequently vanished . @ 7 mi ) per year , keeping within 30 km ( 19 mi ) of the Atlantic coast . Since then , despite some initial attempts at eradication , the bird has been expanding its breeding range at an average rate of 7 @. |
= = = = Australia = = = = |
The wide and arid Nullarbor Plain provides a natural barrier and control measures have been adopted that have killed 55 @,@ 000 birds over three decades . Nest @-@ boxes for the newly released birds were placed on farms and near crops . By the 1920s , common starlings were widespread throughout Victoria , Queensland and New South Wales , but by then they were considered to be pests . Although common starlings were first sighted in Albany , Western Australia in 1917 , they have been largely prevented from spreading to the state . By the 1880s , established populations were present in the southeast of the country thanks to the work of acclimatisation committees . The common starling has also colonised Lord Howe Island and Norfolk Island . The common starling was introduced to Australia to consume insect pests of farm crops . The common starling was introduced to Melbourne in 1857 and Sydney two decades later . Early settlers looked forward to their arrival , believing that common starlings were also important for the pollination of flax , a major agricultural product . |
= = = = New Zealand = = = = |
The birds soon became established and are now found all over the country including the subtropical Kermadec Islands to the north and the equally distant Macquarie Island far to the south . Native birds were not habituated to living in close proximity to man so the common starling was introduced from Europe to control the pests . The early settlers in New Zealand cleared the bush and found their newly planted crops were invaded by hordes of caterpillars and other insects deprived of their previous food sources . It was first brought over in 1862 by the Nelson Acclimatisation Society and other introductions followed . |
= = = = North America = = = = |
The original 60 birds have since swelled in number to 150 million , occupying an area extending from southern Canada and Alaska to Central America . About the same date , the Portland Song Bird Club released 35 pairs of common starlings in Portland , Oregon . Common starlings reappeared in the Pacific Northwest in the mid @-@ 1940s and these birds were probably descendants of the 1890 Central Park introduction . These birds became established but disappeared around 1902 . He was president of the American Acclimatization Society , which tried to introduce every bird species mentioned in the works of William Shakespeare into North America . After two failed attempts , about 60 common starlings were released in 1890 into New York 's Central Park by Eugene Schieffelin . |
= = = = Polynesia = = = = |
Its spread in Fiji has been limited , and there are doubts about the population 's viability . It may have colonised from New Zealand via Raoul in the Kermadec Islands where it is abundant , that group being roughly equidistant between New Zealand and Fiji . Tonga was colonised at about the same date and the birds there have been slowly spreading north through the group . The common starling appears to have arrived in Fiji in 1925 on Ono @-@ i @-@ lau and Vatoa islands . |
= = = = South Africa = = = = |
It breeds from September to December and outside the breeding season may congregate in large flocks , often roosting in reedbeds . It spread slowly and by 1954 had reached Clanwilliam and Port Elizabeth . In South Africa , the common starling was introduced in 1897 by Cecil Rhodes . It may compete with native birds for crevice nesting sites but the indigenous species are probably more disadvantaged by destruction of their natural habitat than they are by inter @-@ specific competition . In Southern Africa populations appear to be resident and the bird is very much associated with man , his habitations and pastures . It is present in the Western Cape , the Eastern Cape and the Free State provinces of South Africa and lowland Lesotho , with occasional sightings in KwaZulu @-@ Natal , Gauteng and around the town of Oranjemund in Namibia . It is now common in the southern Cape region , thinning out northwards to the Johannesburg area . It favours irrigated land and is absent from regions where the ground is baked so dry that it cannot probe for insects . It is the most common bird species in urban and agricultural areas . |
= = = = West Indies = = = = |
The common starling was introduced to Jamaica in 1903 , and the Bahamas and Cuba were colonised naturally from the US . This bird is fairly common but local in Jamaica , Grand Bahama and Bimini , and is rare in the rest of the Bahamas , eastern Cuba , the Cayman Islands , Puerto Rico and St. Croix . |
= = Status = = |
@ 9 mi ) per year for both species , is due to the suboptimal mountain and woodland terrain . The common starling has bred in northern Sweden from 1850 and in Iceland from 1935 . Expansion has since slowed even further due to direct competition between the two similar species where they overlap in southwestern France and northwestern Spain . The low rate of advance , about 4 @. @ 7 km ( 2 @. It started breeding in Iberia in 1960 , while the spotless starling 's range had been expanding northward since the 1950s . It had shown a marked increase in numbers throughout Europe from the 19th century to around the 1950s and 60s . The breeding range spread through southern France to northeastern Spain , and there were other range expansions particularly in Italy , Austria and Finland . The global population of the common starling is estimated to be more than 310 million individuals and its numbers are not thought to be declining significantly , so the bird is classified by the International Union for Conservation of Nature as being of least concern . In about 1830 , S. v. vulgaris expanded its range in the British Isles , spreading into Ireland and areas of Scotland where it had formerly been absent , although S. v. zetlandicus was already present in Shetland and the Outer Hebrides . |
The intensive farming methods used in northern Europe mean there is less pasture and meadow habitat available , and the supply of grassland invertebrates needed for the nestlings to thrive is correspondingly reduced . The overall decline seems to be due to the low survival rate of young birds , which may be caused by changes in agricultural practices . Numbers dwindled in the United Kingdom by more than 80 % between 1966 and 2004 ; although populations in some areas such as Northern Ireland were stable or even increased , those in other areas , mainly England , declined even more sharply . The bird has been adversely affected in these areas by intensive agriculture , and in several countries it has been red @-@ listed due to population declines of more than 50 % . Major declines in populations have been observed from 1980 onward in Sweden , Finland , northern Russia ( Karelia ) and the Baltic States , and smaller declines in much of the rest of northern and central Europe . |
= = Relationship with humans = = |
= = = Benefits and problems = = = |
Around 25 million nest boxes were erected for this species in the former Soviet Union , and common starlings were found to be effective in controlling the grass grub Costelytra zelandica in New Zealand . Since common starlings eat insect pests such as wireworms , they are considered beneficial in northern Eurasia , and this was one of the reasons given for introducing the birds elsewhere . The original Australian introduction was facilitated by the provision of nest boxes to help this mainly insectivorous bird to breed successfully , and even in the US , where this is a pest species , the Department of Agriculture acknowledges that vast numbers of insects are consumed by common starlings . |
In North America , chickadees , nuthatches , woodpeckers , purple martins and other swallows may be affected . For its role in the decline of local native species and the damages to agriculture , the common starling has been included in the IUCN List of the world 's 100 worst invasive species . Common starlings introduced to areas such as Australia or North America , where other members of the genus are absent , may affect native species through competition for nest holes . In Australia , competitors for nesting sites include the crimson and eastern rosellas . |
Common starlings can eat and damage fruit in orchards such as grapes , peaches , olives , currants and tomatoes or dig up newly sown grain and sprouting crops . In eastern Australia , weeds like bridal creeper , blackberry and boneseed are thought to have been spread by common starlings . Agricultural damage in the US is estimated as costing about US $ 800 million annually . This bird is not considered to be as damaging to agriculture in South Africa as it is in the United States . They may also eat animal feed and distribute seeds through their droppings . |