Common starling

The common starling (Sturnus vulgaris), also known as the European starling in
North America an simply as the starling in Great Britain an Irelan, is a
meium-size passerine bir in the starling family, Sturniae. It is about 20 cm
(8 in) long an has glossy black plumage with a metallic sheen, which is
speckle with white at some times of year. The legs are pink an the bill is
black in winter an yellow in summer; young birs have browner plumage than the
aults. It is a noisy bir, especially in communal roosts an other gregarious
situations, with an unmusical but varie song. Its gift for mimicry has been
note in literature incluing the Mabinogion an the works of Pliny the Eler
an William Shakespeare.

The common starling has about 12 subspecies breeing in open habitats across its
native range in temperate Europe an across the Palearctic to western Mongolia,
an it has been introuce as an invasive species to Australia, New Zealan,
Canaa, the Unite States, Mexico, Argentina, South Africa an Fiji. This
bir is resient in western an southern Europe an southwestern Asia, while
northeastern populations migrate south an west in the winter within the
breeing range an also further south to Iberia an North Africa. The common
starling buils an untiy nest in a natural or artificial cavity in which four
or five glossy, pale blue eggs are lai. These take two weeks to hatch an the
young remain in the nest for another three weeks. There are normally one or two
breeing attempts each year. This species is omnivorous, taking a wie range of
invertebrates, as well as sees an fruit. It is hunte by various mammals an
birs of prey, an is host to a range of external an internal parasites.

Behaviour an ecology

The common starling is a highly gregarious species, especially in autumn an
winter. Although flock size is highly variable, huge, noisy flocks
(murmurations) may form near roosts. These ense concentrations of birs are
thought to be a efence against attacks by birs of prey such as peregrine
falcons or Eurasian sparrowhawks. Flocks form a tight sphere-like formation in
flight, frequently expaning an contracting an changing shape, seemingly
without any sort of leaer. Each common starling changes its course an spee as
a result of the movement of its closest neighbours.

Very large roosts, up to 1.5 million birs, form in city centres, woolans an
reebes, causing problems with their roppings. These may accumulate up to 30
cm (12 in) eep, killing trees by their concentration of chemicals. In smaller
amounts, the roppings act as a fertiliser, an therefore woolan managers may
try to move roosts from one area of a woo to another to benefit from the soil
enhancement an avoi large toxic eposits.

Flocks of more than a million common starlings may be observe just before
sunset in spring in southwestern Jutlan, Denmark, over the seawar marshlans
of Tøner an Esbjerg municipalities between Tøner an Ribe. They gather in
March until northern Scaninavian birs leave for their breeing ranges by
mi-April. Their swarm behaviour creates complex shapes silhouette against the
sky, a phenomenon known locally as sort sol ("black sun"). Flocks of
anything from five to fifty thousan common starlings form in areas of the UK
just before sunown uring mi-winter. These flocks are commonly calle
murmurations.

Feeing

The common starling is largely insectivorous an fees on both pest an other
arthropos. The foo range inclues spiers, crane flies, moths, mayflies,
ragonflies, amsel flies, grasshoppers, earwigs, lacewings, caisflies, flies,
beetles, sawflies, bees, wasps an ants. Prey are consume in both ault an
larvae stages of evelopment, an common starlings will also fee on earthworms,
snails, small amphibians an lizars. While the consumption of invertebrates is
necessary for successful breeing, common starlings are omnivorous an can also
eat grains, sees, fruits, nectar an foo waste if the opportunity arises. The
Sturniae iffer from most birs in that they cannot easily metabolise foos
containing high levels of sucrose, although they can cope with other fruits such
as grapes an cherries. The isolate Azores subspecies of the common starling
eats the eggs of the enangere roseate tern. Measures are being introuce to
reuce common starling populations by culling before the terns return to their
breeing colonies in spring.

There are several methos by which common starlings obtain their foo, but, for
the most part, they forage close to the groun, taking insects from the surface
or just unerneath. Generally, common starlings prefer foraging amongst
short-croppe grasses an eat with grazing animals or perch on their backs,
where they will also fee on the mammal's external parasites. Large flocks may
engage in a practice known as "roller-feeing", where the birs at the back of
the flock continually fly to the front where the feeing opportunities are best.
The larger the flock, the nearer iniviuals are to one another while foraging.
Flocks often fee in one place for some time, an return to previous
successfully forage sites.

Nesting

Unpaire males fin a suitable cavity an begin to buil nests in orer to
attract single females, often ecorating the nest with ornaments such as flowers
an fresh green material, which the female later isassembles 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 ecorative material appears to
be significant in attracting a mate. The scent of plants such as yarrow acts as
an olfactory attractant to females.

The males sing throughout much of the construction an even more so when a
female approaches his nest. Following copulation, the male an female continue
to buil the nest. Nests may be in any type of hole, common locations inclue
insie hollowe trees, builings, tree stumps an man-mae nest-boxes. S. v.
zetlanicus typically brees in crevices an holes in cliffs, a habitat only
rarely use by the nominate form. Nests are typically mae out of straw, ry
grass an twigs with an inner lining mae up of feathers, wool an soft leaves.
Construction usually takes four or five ays an may continue through
incubation.

Breeing

Breeing takes place uring the spring an summer. Following copulation, the
female lays eggs on a aily basis over a perio of several ays. If an egg is
lost uring this time, she will lay another to replace it. There are normally
four or five eggs that are ovoi in shape an pale blue or occasionally white,
an they commonly have a glossy appearance. The colour of the eggs seems to
have evolve through the relatively goo visibility of blue at low light
levels. The egg size is 26.5–34.5 mm (1.04–1.36 in) in length an 20.0–22.5
mm (0.79–0.89 in) in maximum iameter.

The young are born blin an nake. They evelop light fluffy own within seven
ays of hatching an can see within nine ays. As with other passerines, the
nest is kept clean an the chicks' faecal sacs are remove by the aults. Once
the chicks are able to regulate their boy temperature, about six ays after
hatching, the aults largely cease removing roppings from the nest. Prior to
that, the fouling woul wet both the chicks' plumage an the nest material,
thereby reucing their effectiveness as insulation an increasing the risk of
chilling the hatchlings. Nestlings remain in the nest for three weeks, where
they are fe continuously by both parents. Fleglings continue to be fe by
their parents for another one or two weeks. Within two months, most juveniles
will have moulte an gaine their first basic plumage. They acquire their ault
plumage the following year.

Predators an parasites

A majority of starling preators are avian. The typical response of starling
groups is to take flight, with a common sight being unulating flocks of starling
flying high in quick an agile patterns. Their abilities in flight are selom
matche by birs of prey. Ault common starlings are hunte by hawks such as the
northern goshawk (Accipiter gentilis) an Eurasian sparrowhawk (Accipiter nisus),
an falcons incluing the peregrine falcon (Falco peregrinus), Eurasian hobby
(Falco subbuteo) an common kestrel (Falco tinnunculus). Slower raptors like
black an re kites (Milvus migrans & milvus), eastern imperial eagle (Aquila
heliaca), common buzzar (Buteo buteo) an Australasian harrier (Circus
approximans) ten to take the more easily caught fleglings or juveniles. While
perche in groups by night, they can be vulnerable to owls, incluing the little
owl (Athene noctua), long-eare owl (Asio otus), short-eare owl (Asio flammeus),
barn owl (Tyto alba), tawny owl (Strix aluco) an Eurasian eagle-owl (Bubo bubo).

More than twenty species of hawk, owl and falcon are known to occasionally
predate 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. Starlings are more commonly the culprits rather than victims of nest
eviction however, especially towards other starlings and woodpeckers.
Nests can be raided by mammals capable of climbing to them, such as small
mustelids (Mustela spp.), raccoons (Procyon lotor) and squirrels
(Sciurus spp.), and cats may catch the unwary.

Common starlings are hosts to a wide range of parasites. 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. A bird with a
deformed bill was heavily infested with Mallophaga lice, presumably due to its
inability to remove vermin.

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 farther south and extending into
the Maldives) Nepal, the Middle East including Israel, Syria, Iran, and Iraq,
and northwestern China.

Common starlings in the south and west of Europe and south of latitude 40°N are
mainly resident, although other populations migrate from regions where the
winter is harsh, the ground frozen and food scarce. Large numbers of birds from
northern Europe, Russia and Ukraine migrate south westwards or south eastwards.
In the autumn, when immigrants are arriving from eastern Europe, many of
Britain's common starlings are setting off for Iberia and North Africa. Other
groups of birds are in passage across the country and the pathways of these
different streams of bird may cross. 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. Small numbers of common starlings have sporadically been observed
in Japan and Hong Kong but it is unclear whence these birds originated. In North
America, northern populations have developed a migration pattern, vacating much
of Canada in winter. Birds in the east of the country move southwards, and those
from farther west winter in the southwest of the US.

Common starlings prefer urban or suburban areas where artificial structures and
trees provide adequate nesting and roosting sites. 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. 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. rainforests or wet sclerophyll
forests) but are found in coastal areas, where they nest and roost on cliffs and
forage amongst seaweed. 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.

Introduced populations

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. As a result, it has also been able to migrate to Thailand,
Southeast Asia and New Guinea.

South America

Five individuals conveyed on a ship from England alighted near Lago de Maracaibo
in Venezuela in November 1949, but subsequently vanished. In 1987, a small
population of common starlings was observed nesting in gardens in the city of
Buenos Aires. Since then, despite some initial attempts at eradication, the bird
has been expanding its breeding range at an average rate of 7.5 km (4.7 mi) per
year, keeping within 30 km (19 mi) of the Atlantic coast. In Argentina, the
species makes use of a variety of natural and man-made nesting sites,
particularly woodpecker holes.

Australia

The common starling was introduced to Australia to consume insect pests of farm
crops. Early settlers looked forward to their arrival, believing that common
starlings were also important for the pollination of flax, a major agricultural
product. Nest-boxes for the newly released birds were placed on farms and near
crops. The common starling was introduced to Melbourne in 1857 and Sydney two
decades later. By the 1880s, established populations were present in the
southeast of the country thanks to the work of acclimatisation committees. 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. 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. The common starling has also
colonised Kangaroo Island, Lord Howe Island, Norfolk Island and Tasmania.

New Zealand

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. Native birds were not habituated to living in close
proximity to man so the common starling was introduced from Europe along with
the house sparrow to control the pests. It was first brought over in 1862 by the
Nelson Acclimatisation Society and other introductions followed. 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.

North America

Various acclimatisation society records mention instances of starlings being
introduced in Cincinnati, Quebec and New York in the 1870s. As part of a
nationwide effort, about 60 common starlings were released in 1890 into New
York's Central Park by Eugene Schieffelin, president of the American
Acclimatization Society. It has been widely reported that he had tried to
introduce every bird species mentioned in the works of William Shakespeare into
North America, but this claim has been traced to an essay in 1948 by naturalist
Edwin Way Teale, whose notes appear to indicate that it was speculation. About
the same date, the Portland Song Bird Club released 35 pairs of common starlings
in Portland, Oregon. Earlier introductions are recorded to have died out within
a few years, with the 1890 New York and Portland introductions reported as being
the most successful. Population of the birds is estimated to have grown to 150
million, occupying an area extending from southern Canada and Alaska to Central
America.

Status

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. It had shown a marked increase
in numbers throughout Europe from the 19th century to around the 1950s and 60s.
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
common starling has bred in northern Sweden from 1850 and in Iceland from 1935.
The breeding range spread through southern France to northeastern Spain, and
there were other range expansions particularly in Italy, Austria and Finland. It
started breeding in Iberia in 1960, while the spotless starling's range had been
expanding northward since the 1950s. The low rate of advance, about 4.7 km (2.9
mi) per year for both species, is due to the suboptimal mountain and woodland
terrain. Expansion has since slowed even further due to direct competition
between the two similar species where they overlap in southwestern France and
northwestern Spain.

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. 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%. 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
overall decline seems to be due to the low survival rate of young birds, which
may be caused by changes in agricultural practices. 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.

Relationship with humans

Benefits and problems

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. 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 zealandica in New Zealand.
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.

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 North America, chickadees, nuthatches,
woodpeckers, purple martins and other swallows may be affected. In Australia,
competitors for nesting sites include the crimson and eastern rosellas. 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.

European, or common, starlings are habitat generalists meaning they are able to
exploit a multitude of habitats, nest sites and food sources. This, coupled with
them being lowland birds that easily coexist with humans, enables them to take
advantage of other native birds, most particularly woodpecker. European
starlings are considered aggressive omnivores that utilize an open-bill probing
technique that gives them an evolutionary advantage over birds that are
frugivores. Their aggressive and gregarious behaviour in terms of food thus
allows them to outcompete native species. Common starlings are also aggressive
in the creation of their nest cavities. Often, starlings will usurp a nest site,
for example a tree hollow, and fill it rapidly with bedding and contaminants
compared to other species, like the native parrots, that use little to no
bedding. As cavity nesters, they are able to outcompete many native species in
terms of habitat and nest sites.

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.
They may also eat animal feed and distribute seeds through their droppings. 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.

Control

Due to the impact of starlings on crop production, there have been attempts to
control the numbers of both native and introduced populations of common
starlings. Within the natural breeding range, this may be affected by
legislation. For example, in Spain, the species is hunted commercially as a food
item, and has a closed season, whereas in France, it is classed as a pest, and
the season in which it may be killed covers the greater part of the year. In
Great Britain, starlings are protected under the Wildlife and Countryside Act
1981, which makes it "illegal to intentionally kill, injure or take a starling,
or to take, damage or destroy an active nest or its contents". The Wildlife
Order in Northern Ireland allows, with a general licence, "an authorised person
to control starlings to prevent serious damage to agriculture or preserve public
health and safety". The species is migratory, so birds involved in control
measures may have come from a wide area and breeding populations may not be
greatly affected. In Europe, the varying legislation and mobile populations mean
that control attempts may have limited long-term results. Non-lethal techniques
such as scaring with visual or auditory devices have only a temporary effect in
any case.

Huge urban roosts in cities can create problems due to the noise and mess made
and the smell of the droppings. In 1949, so many birds landed on the clock hands
of London's Big Ben that it stopped, leading to unsuccessful attempts to disrupt
the roosts with netting, repellent chemical on the ledges and broadcasts of
common starling alarm calls. An entire episode of The Goon Show in 1954 was a
parody of the futile efforts to disrupt the large common starling roosts in
central London.

In science and culture

Common starlings may be kept as pets or as laboratory animals. Austrian
ethologist Konrad Lorenz wrote of them in his book King Solomon's Ring as "the
poor man's dog" and "something to love", because nestlings are easily obtained
from the wild and after careful hand rearing they are straightforward to look
after. They adapt well to captivity, and thrive on a diet of standard bird feed
and mealworms. Several birds may be kept in the same cage, and their
inquisitiveness makes them easy to train or study. The only disadvantages are
their messy and indiscriminate defecation habits and the need to take
precautions against diseases that may be transmitted to humans. As a laboratory
bird, the common starling is second in numbers only to the domestic pigeon.

The common starling's gift for mimicry has long been recognised. In the medieval
Welsh Mabinogion, Branwen tamed a common starling, "taught it words", and sent
it across the Irish Sea with a message to her brothers, Bran and Manawydan, who
then sailed from Wales to Ireland to rescue her. Pliny the Elder claimed that
these birds could be taught to speak whole sentences in Latin and Greek, and in
Henry IV, William Shakespeare had Hotspur declare "The king forbade my tongue to
speak of Mortimer. But I will find him when he is asleep, and in his ear I'll
holler 'Mortimer!' Nay I'll have a starling shall be taught to speak nothing but
Mortimer, and give it to him to keep his anger still in motion."

Mozart had a pet common starling which could sing part of his Piano Concerto in
G Major (KV. 453). He had bought it from a shop after hearing it sing a phrase
from a work he wrote six weeks previously, which had not yet been performed in
public. He became very attached to the bird and arranged an elaborate funeral
for it when it died three years later. It has been suggested that his A Musical
Joke (K. 522) might be written in the comical, inconsequential style of a
starling's vocalisation. Other people who have owned common starlings report how
adept they are at picking up phrases and expressions. The words have no meaning
for the starling, so they often mix them up or use them on what to humans are
inappropriate occasions in their songs. Their ability at mimicry is so great
that strangers have looked in vain for the human they think they have just heard
speak.

Common starlings are trapped for food in some Arab countries. The meat is tough
and of low quality, so it is casseroled or made into pâté. One recipe said it
should be stewed "until tender, however long that may be". Even when correctly
prepared, it may still be seen as an acquired taste.