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The western jackdaw (''Coloeus monedula''), also known as the Eurasian jackdaw, the European jackdaw, or simply the jackdaw, is a
passerine A passerine () is any bird of the order Passeriformes (; from Latin 'sparrow' and '-shaped'), which includes more than half of all bird species. Sometimes known as perching birds, passerines are distinguished from other orders of birds by th ...
bird in the crow family. Found across Europe,
western Asia Western Asia, West Asia, or Southwest Asia, is the westernmost subregion of the larger geographical region of Asia, as defined by some academics, UN bodies and other institutions. It is almost entirely a part of the Middle East, and includes A ...
and North Africa; it is mostly resident, although northern and eastern populations migrate south in the winter. Four
subspecies In biological classification, subspecies is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics ( morphology), but that can successfully interbreed. Not all specie ...
are recognised, which differ mainly in the colouration of the plumage on the head and nape. Linnaeus first described it formally, giving it the name ''Corvus monedula''. The common name derives from the word ''jack'', denoting "small", and daw, a less common
synonym A synonym is a word, morpheme, or phrase that means exactly or nearly the same as another word, morpheme, or phrase in a given language. For example, in the English language, the words ''begin'', ''start'', ''commence'', and ''initiate'' are al ...
for "jackdaw", and the native English name for the bird. Measuring in length, the western jackdaw is a black-plumaged bird with a grey nape and distinctive pale-grey irises. It is gregarious and vocal, living in small groups with a complex social structure in farmland, open woodland, on coastal cliffs, and in urban settings. Like its relatives, jackdaws are intelligent birds, and have been observed using tools. An omnivorous and opportunistic feeder, it eats a wide variety of plant material and
invertebrate Invertebrates are a paraphyletic group of animals that neither possess nor develop a vertebral column (commonly known as a ''backbone'' or ''spine''), derived from the notochord. This is a grouping including all animals apart from the chorda ...
s, as well as food waste from urban areas. Western jackdaws are
monogamous Monogamy ( ) is a form of dyadic relationship in which an individual has only one partner during their lifetime. Alternately, only one partner at any one time ( serial monogamy) — as compared to the various forms of non-monogamy (e.g., pol ...
and build simple nests of sticks in cavities in trees, cliffs, or buildings. About five pale blue or blue-green eggs with brown speckles are laid and incubated by the female. The young fledge in four to five weeks.


Systematics


Etymology

The western jackdaw was one of the many species originally described by
Carl Linnaeus Carl Linnaeus (; 23 May 1707 – 10 January 1778), also known after his ennoblement in 1761 as Carl von Linné Blunt (2004), p. 171. (), was a Swedish botanist, zoologist, taxonomist, and physician who formalised binomial nomenclature, ...
in his 18th century work ''
Systema Naturae ' (originally in Latin written ' with the ligature æ) is one of the major works of the Swedish botanist, zoologist and physician Carl Linnaeus (1707–1778) and introduced the Linnaean taxonomy. Although the system, now known as binomial ...
''. Owing to its supposed fondness for picking up coins, Linnaeus gave it the binomial name ''Corvus monedula'', choosing the specific name ''mǒnēdŭla'', which is derived from ''
moneta In Roman mythology, Moneta ( Latin Monēta) was a title given to two separate goddesses: It was the name of the goddess of memory (identified with the Greek goddess Mnemosyne), and it was an epithet of Juno, called Juno Moneta (Latin Iūno Mon ...
'', the Latin stem of the word "money". Jackdaws are sometimes placed in the genus '' Coloeus'', from the
Ancient Greek Ancient Greek includes the forms of the Greek language used in ancient Greece and the ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Dark Ages (), the Archaic pe ...
κολοιός (''koloios'') for jackdaw, though most subsequent works have retained the two jackdaw species in ''Corvus''. The original
Old English Old English (, ), or Anglo-Saxon, is the earliest recorded form of the English language, spoken in England and southern and eastern Scotland in the early Middle Ages. It was brought to Great Britain by Anglo-Saxon settlers in the mid-5th ...
words ''ċēo'' and ''ċeahhe'' (pronounced with initial ''ch'') gave modern English "
chough There are two species of passerine birds commonly called chough ( ) that constitute the genus ''Pyrrhocorax'' of the Corvidae (crow) family of birds. These are the red-billed chough (''Pyrrhocorax pyrrhocorax''), and the Alpine chough (or yello ...
";
Chaucer Geoffrey Chaucer (; – 25 October 1400) was an English poet, author, and civil servant best known for '' The Canterbury Tales''. He has been called the "father of English literature", or, alternatively, the "father of English poetry". He w ...
sometimes used this word to refer to the western jackdaw, as did
Shakespeare William Shakespeare ( 26 April 1564 – 23 April 1616) was an English playwright, poet and actor. He is widely regarded as the greatest writer in the English language and the world's pre-eminent dramatist. He is often called England's nation ...
in ''
Hamlet ''The Tragedy of Hamlet, Prince of Denmark'', often shortened to ''Hamlet'' (), is a tragedy written by William Shakespeare sometime between 1599 and 1601. It is Shakespeare's longest play, with 29,551 words. Set in Denmark, the play depicts ...
'' although there has been debate about which species he was referring to. This
onomatopoeic Onomatopoeia is the process of creating a word that phonetically imitates, resembles, or suggests the sound that it describes. Such a word itself is also called an onomatopoeia. Common onomatopoeias include animal noises such as ''oink'', ''m ...
name, based on the western jackdaw's call, now refers to corvids of the genus '' Pyrrhocorax''; the red-billed chough (''Pyrrhocorax pyrrhocorax''), formerly particularly common in
Cornwall Cornwall (; kw, Kernow ) is a Historic counties of England, historic county and Ceremonial counties of England, ceremonial county in South West England. It is recognised as one of the Celtic nations, and is the homeland of the Cornish people ...
, became known initially as the "Cornish chough" and then just the "chough", the name transferring from one species to the other. The common name ''jackdaw'' first appeared in the 16th century, and is thought to be a compound of the forename ''Jack'', used in animal names to signify a small form (e.g.
jack snipe The jack snipe or jacksnipe (''Lymnocryptes minimus'') is a small stocky wader. It is the smallest snipe, and the only member of the genus ''Lymnocryptes''. Features such as its sternum make it quite distinct from other snipes or woodcocks. ...
), and the archaic native English word ''daw''. Formerly, western jackdaws were simply called "daws". Goodwin, p. 78 The metallic ''chyak'' call may be the origin of the ''jack'' part of the common name, but this is not supported by the ''
Oxford English Dictionary The ''Oxford English Dictionary'' (''OED'') is the first and foundational historical dictionary of the English language, published by Oxford University Press (OUP). It traces the historical development of the English language, providing a c ...
''. ''Daw'', first used for the bird in the 15th century, is held by the ''Oxford English Dictionary'' to be derived from the postulated
Old English Old English (, ), or Anglo-Saxon, is the earliest recorded form of the English language, spoken in England and southern and eastern Scotland in the early Middle Ages. It was brought to Great Britain by Anglo-Saxon settlers in the mid-5th ...
''dawe'', citing the
cognate In historical linguistics, cognates or lexical cognates are sets of words in different languages that have been inherited in direct descent from an etymological ancestor in a common parent language. Because language change can have radical ef ...
s in
Old High German Old High German (OHG; german: Althochdeutsch (Ahd.)) is the earliest stage of the German language, conventionally covering the period from around 750 to 1050. There is no standardised or supra-regional form of German at this period, and Old Hig ...
''tāha'',
Middle High German Middle High German (MHG; german: Mittelhochdeutsch (Mhd.)) is the term for the form of German spoken in the High Middle Ages. It is conventionally dated between 1050 and 1350, developing from Old High German and into Early New High German. Hig ...
''tāhe'' or ''tāchele'', and modern German ''Dahle'' or ''Dohle'', and dialectal ''Tach, Dähi, Däche'' and ''Dacha''. Names in English dialects are numerous. Scottish and north English dialects have included ''ka'' or ''kae'' since the 14th century. The Midlands form of this word was ''co'' or ''coo''. ''Caddow'' is potentially a compound of ''ka'' and ''dow'', a variant of ''daw''. Other dialectal or obsolete names include ''caddesse'', ''cawdaw'', ''caddy'', ''chauk'', ''college-bird'', ''jackerdaw'', ''jacko'', ''ka-wattie'', ''chimney-sweep bird'' (from their nesting propensities), and ''sea-crow'' (from the frequency with which they are found on coasts). It was also frequently known quasi-nominally as ''Jack''. An archaic collective noun for a group of jackdaws is a "clattering". Another name for a flock is a "train".


Taxonomy

A study in 2000 found that the genetic distance between western jackdaws and the other members of ''Corvus'' was greater than that within the rest of the genus. This led Pamela Rasmussen to reinstate the genus name ''Coloeus'', created by Johann Kaup in 1829, in her ''
Birds of South Asia Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweight ...
'' (2005), a treatment also used in a 1982 systematic list in German by Hans Edmund Wolters. A study of corvid
phylogeny A phylogenetic tree (also phylogeny or evolutionary tree Felsenstein J. (2004). ''Inferring Phylogenies'' Sinauer Associates: Sunderland, MA.) is a branching diagram or a tree showing the evolutionary relationships among various biological s ...
undertaken in 2007 compared DNA sequences in the mitochondrial control region of several corvids. It found that the western jackdaw, and the closely related Daurian jackdaw (''C. dauuricus'') of eastern
Russia Russia (, , ), or the Russian Federation, is a transcontinental country spanning Eastern Europe and Northern Asia. It is the largest country in the world, with its internationally recognised territory covering , and encompassing one-ei ...
and
China China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's List of countries and dependencies by population, most populous country, with a Population of China, population exceeding 1.4 billion, slig ...
, were basal to the core ''Corvus''
clade A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English ter ...
. The names ''Coloeus monedula'' and ''Coloeus dauuricus'' have since been adopted by the International Ornithological Congress in their official list. The two species of jackdaw have been reported to hybridise in the
Altai Mountains The Altai Mountains (), also spelled Altay Mountains, are a mountain range in Central and East Asia, where Russia, China, Mongolia and Kazakhstan converge, and where the rivers Irtysh and Ob have their headwaters. The massif merges with the ...
, southern
Siberia Siberia ( ; rus, Сибирь, r=Sibir', p=sʲɪˈbʲirʲ, a=Ru-Сибирь.ogg) is an extensive geographical region, constituting all of North Asia, from the Ural Mountains in the west to the Pacific Ocean in the east. It has been a part ...
, and
Mongolia Mongolia; Mongolian script: , , ; lit. "Mongol Nation" or "State of Mongolia" () is a landlocked country in East Asia, bordered by Russia to the north and China to the south. It covers an area of , with a population of just 3.3 million ...
. Analysis of the
mitochondrial DNA Mitochondrial DNA (mtDNA or mDNA) is the DNA located in mitochondria, cellular organelles within eukaryotic cells that convert chemical energy from food into a form that cells can use, such as adenosine triphosphate (ATP). Mitochondrial D ...
of specimens of the two species from their core ranges show them to be genetically distinct.


Subspecies

There are four recognized subspecies of the western jackdaw. All European subspecies intergrade where their populations meet. Goodwin, p. 75 ''C. m. monedula'' intergrades into ''C. m. soemmerringii'' in a transition zone running from
Finland Finland ( fi, Suomi ; sv, Finland ), officially the Republic of Finland (; ), is a Nordic country in Northern Europe. It shares land borders with Sweden to the northwest, Norway to the north, and Russia to the east, with the Gulf of Bot ...
south across the
Baltic Baltic may refer to: Peoples and languages *Baltic languages, a subfamily of Indo-European languages, including Lithuanian, Latvian and extinct Old Prussian *Balts (or Baltic peoples), ethnic groups speaking the Baltic languages and/or originatin ...
and eastern
Poland Poland, officially the Republic of Poland, is a country in Central Europe. It is divided into 16 administrative provinces called voivodeships, covering an area of . Poland has a population of over 38 million and is the fifth-most populou ...
to
Romania Romania ( ; ro, România ) is a country located at the crossroads of Central Europe, Central, Eastern Europe, Eastern, and Southeast Europe, Southeastern Europe. It borders Bulgaria to the south, Ukraine to the north, Hungary to the west, S ...
and
Croatia , image_flag = Flag of Croatia.svg , image_coat = Coat of arms of Croatia.svg , anthem = " Lijepa naša domovino"("Our Beautiful Homeland") , image_map = , map_caption = , capi ...
. *The Nordic jackdaw (''C. m. monedula'') (Linnaeus, 1758), the
nominate subspecies In biological classification, subspecies is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics ( morphology), but that can successfully interbreed. Not all speci ...
, is found in eastern Europe. Its range extends across
Scandinavia Scandinavia; Sámi languages: /. ( ) is a subregion in Northern Europe, with strong historical, cultural, and linguistic ties between its constituent peoples. In English usage, ''Scandinavia'' most commonly refers to Denmark, Norway, and S ...
, from southern Finland south to
Esbjerg Esbjerg (, ) is a seaport town and seat of Esbjerg Municipality on the west coast of the Jutland peninsula in southwest Denmark. By road, it is west of Kolding and southwest of Aarhus. With an urban population of 71,698 (1 January 2022) ...
and Haderslev in
Denmark ) , song = ( en, "King Christian stood by the lofty mast") , song_type = National and royal anthem , image_map = EU-Denmark.svg , map_caption = , subdivision_type = Sovereign state , subdivision_name = Kingdom of Denmark , establish ...
, through eastern
Germany Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated betwee ...
and Poland, and south across eastern central Europe to the
Carpathian Mountains The Carpathian Mountains or Carpathians () are a range of mountains forming an arc across Central Europe. Roughly long, it is the third-longest European mountain range after the Urals at and the Scandinavian Mountains at . The range stretche ...
and northwestern Romania, Vojvodina in northern
Serbia Serbia (, ; Serbian: , , ), officially the Republic of Serbia ( Serbian: , , ), is a landlocked country in Southeastern and Central Europe, situated at the crossroads of the Pannonian Basin and the Balkans. It shares land borders with Hu ...
, and
Slovenia Slovenia ( ; sl, Slovenija ), officially the Republic of Slovenia (Slovene: , abbr.: ''RS''), is a country in Central Europe. It is bordered by Italy to the west, Austria to the north, Hungary to the northeast, Croatia to the southeast, and ...
. Cramp, p. 120. It breeds in south-eastern
Norway Norway, officially the Kingdom of Norway, is a Nordic countries, Nordic country in Northern Europe, the mainland territory of which comprises the western and northernmost portion of the Scandinavian Peninsula. The remote Arctic island of ...
, southern
Sweden Sweden, formally the Kingdom of Sweden,The United Nations Group of Experts on Geographical Names states that the country's formal name is the Kingdom of SwedenUNGEGN World Geographical Names, Sweden./ref> is a Nordic countries, Nordic c ...
, and northern and eastern Denmark, with occasional wintering in
England England is a country that is part of the United Kingdom. It shares land borders with Wales to its west and Scotland to its north. The Irish Sea lies northwest and the Celtic Sea to the southwest. It is separated from continental Europe ...
and
France France (), officially the French Republic ( ), is a country primarily located in Western Europe. It also comprises of Overseas France, overseas regions and territories in the Americas and the Atlantic Ocean, Atlantic, Pacific Ocean, Pac ...
. It has been recorded as a rare vagrant to
Spain , image_flag = Bandera de España.svg , image_coat = Escudo de España (mazonado).svg , national_motto = '' Plus ultra'' (Latin)(English: "Further Beyond") , national_anthem = (English: "Royal March") , ...
. It has a pale nape and sides of the neck, a dark throat, and a light grey partial collar of variable extent. *The Western Eurasian jackdaw (''C. m. spermologus'') (
Vieillot Louis Pierre Vieillot (10 May 1748, Yvetot – 24 August 1830, Sotteville-lès-Rouen) was a French ornithologist. Vieillot is the author of the first scientific descriptions and Linnaean names of a number of birds, including species he collecte ...
, 1817) occurs in western, central and southern Europe and North Africa, from the
British Isles The British Isles are a group of islands in the North Atlantic Ocean off the north-western coast of continental Europe, consisting of the islands of Great Britain, Ireland, the Isle of Man, the Inner and Outer Hebrides, the Northern Isl ...
, the
Netherlands ) , anthem = ( en, "William of Nassau") , image_map = , map_caption = , subdivision_type = Sovereign state , subdivision_name = Kingdom of the Netherlands , established_title = Before independence , established_date = Spanish Netherl ...
and the
Rhineland The Rhineland (german: Rheinland; french: Rhénanie; nl, Rijnland; ksh, Rhingland; Latinised name: ''Rhenania'') is a loosely defined area of Western Germany along the Rhine, chiefly its middle section. Term Historically, the Rhinelands ...
in the north, through western
Switzerland ). Swiss law does not designate a ''capital'' as such, but the federal parliament and government are installed in Bern, while other federal institutions, such as the federal courts, are in other cities (Bellinzona, Lausanne, Luzern, Neuchâtel ...
into
Italy Italy ( it, Italia ), officially the Italian Republic, ) or the Republic of Italy, is a country in Southern Europe. It is located in the middle of the Mediterranean Sea, and its territory largely coincides with the homonymous geographical ...
in the southeast, and the
Iberian peninsula The Iberian Peninsula (), ** * Aragonese and Occitan: ''Peninsula Iberica'' ** ** * french: Péninsule Ibérique * mwl, Península Eibérica * eu, Iberiar penintsula also known as Iberia, is a peninsula in southwestern Europe, def ...
and
Morocco Morocco (),, ) officially the Kingdom of Morocco, is the westernmost country in the Maghreb region of North Africa. It overlooks the Mediterranean Sea to the north and the Atlantic Ocean to the west, and has land borders with Algeria to A ...
in the south. It winters in the
Canary Islands The Canary Islands (; es, :es:Canarias, Canarias, ), also known informally as the Canaries, are a Spanish Autonomous communities of Spain, autonomous community and archipelago in the Atlantic Ocean, in Macaronesia. At their closest point to ...
and
Corsica Corsica ( , Upper , Southern ; it, Corsica; ; french: Corse ; lij, Còrsega; sc, Còssiga) is an island in the Mediterranean Sea and one of the 18 regions of France. It is the fourth-largest island in the Mediterranean and lies southeast of ...
. The name ''"spermologus"'' comes from the Greek σπερμολόγος, ''a picker of seeds''. It is darker in colour than the other subspecies and lacks the whitish border at the base of the grey nape. *The Eastern Eurasian jackdaw (''C. m. soemmerringii'') ( Fischer von Waldheim, 1811) is found in northeastern Europe and northern and central Asia from the former
Soviet Union The Soviet Union,. officially the Union of Soviet Socialist Republics. (USSR),. was a transcontinental country that spanned much of Eurasia from 1922 to 1991. A flagship communist state, it was nominally a federal union of fifteen nationa ...
to
Lake Baikal Lake Baikal (, russian: Oзеро Байкал, Ozero Baykal ); mn, Байгал нуур, Baigal nuur) is a rift lake in Russia. It is situated in southern Siberia, between the federal subjects of Irkutsk Oblast to the northwest and the ...
and northwestern Mongolia and south to
Turkey Turkey ( tr, Türkiye ), officially the Republic of Türkiye ( tr, Türkiye Cumhuriyeti, links=no ), is a transcontinental country located mainly on the Anatolian Peninsula in Western Asia, with a small portion on the Balkan Peninsula ...
,
Israel Israel (; he, יִשְׂרָאֵל, ; ar, إِسْرَائِيل, ), officially the State of Israel ( he, מְדִינַת יִשְׂרָאֵל, label=none, translit=Medīnat Yīsrāʾēl; ), is a country in Western Asia. It is situated ...
and the eastern
Himalayas The Himalayas, or Himalaya (; ; ), is a mountain range in Asia, separating the plains of the Indian subcontinent from the Tibetan Plateau. The range has some of the planet's highest peaks, including the very highest, Mount Everest. Over 10 ...
. Its southwestern limits are Serbia and southern Romania. It winters in Iran and northern India (
Kashmir Kashmir () is the northernmost geographical region of the Indian subcontinent. Until the mid-19th century, the term "Kashmir" denoted only the Kashmir Valley between the Great Himalayas and the Pir Panjal Range. Today, the term encompas ...
). Johann Fischer von Waldheim described this
taxon In biology, a taxon ( back-formation from '' taxonomy''; plural taxa) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular n ...
as ''Corvus soemmerringii'' in 1811, noting its differences from populations in western Europe. Its subspecific name was given in honour of the German anatomist Samuel Thomas von Sömmerring. It is distinguished by the nape and the sides of the neck being paler, creating a contrasting black crown and lighter grey part collar. *The Algerian jackdaw (''C. m. cirtensis'') (
Rothschild Rothschild () is a name derived from the German ''zum rothen Schild'' (with the old spelling "th"), meaning "with the red sign", in reference to the houses where these family members lived or had lived. At the time, houses were designated by sign ...
and Hartert, 1912) is found in Morocco and
Algeria ) , image_map = Algeria (centered orthographic projection).svg , map_caption = , image_map2 = , capital = Algiers , coordinates = , largest_city = capital , relig ...
in Northwest Africa. It was also formerly found in
Tunisia ) , image_map = Tunisia location (orthographic projection).svg , map_caption = Location of Tunisia in northern Africa , image_map2 = , capital = Tunis , largest_city = capital , ...
. The name ''"cirtensis"'' refers to the ancient city of
Cirta Cirta, also known by various other names in antiquity, was the ancient Berber and Roman settlement which later became Constantine, Algeria. Cirta was the capital city of the Berber kingdom of Numidia; its strategically important port city ...
in
Numidia Numidia ( Berber: ''Inumiden''; 202–40 BC) was the ancient kingdom of the Numidians located in northwest Africa, initially comprising the territory that now makes up modern-day Algeria, but later expanding across what is today known as Tunis ...
. The plumage is duller and more uniformly dark grey than the other subspecies, with the paler nape less distinct.


Description

The western jackdaw measures in length and weighs around . Goodwin, p. 74 Most of the plumage is a shiny black, with a purple (in subspecies ''monedula'' and ''spermologus'') or blue (in subspecies ''cirtensis'' and ''soemmerringii'') sheen on the crown, Cramp, p. 139. forehead, and secondaries, and a green-blue sheen on the throat,
primaries Primary elections, or direct primary are a voting process by which voters can indicate their preference for their party's candidate, or a candidate in general, in an upcoming general election, local election, or by-election. Depending on the c ...
, and tail. The cheeks, nape and neck are light grey to greyish-silver, and the underparts are slate-grey. The legs are black, as is the short stout bill, the length of which is about 75% of the length of the rest of the head. There are rictal bristles covering around 40% of the maxilla and 25% of the lower mandible. The irises of adults are greyish or silvery white while those of juveniles are light blue, becoming brownish before whitening at around one year of age. The sexes look alike, though the head and neck plumage of male birds fades more with age and wear, particularly just before moulting. Cramp, p. 137. Western jackdaws undergo a complete moult from June to September in the western parts of their range, and a month later in the east. The purplish sheen of the cap is most prominent just after moulting. Immature birds have duller and less demarcated plumage. The head is a sooty black, sometimes with a faint greenish sheen and brown feather bases visible; the back and side of the neck are dark grey and the underparts greyish or sooty black. The tail has narrower feathers and a greenish sheen. There is very little geographic variation in size. The main differences are the presence or absence of a whitish partial collar at the base of the nape, the variations in the shade of the nape and the tone of the underparts. Populations in central Asia have slightly larger wings and western populations have a slightly heavier bill. Body colour becomes darker further north, in mountain regions and humid climates, and paler elsewhere. However, individual variation, particularly in juveniles and also during the months before moulting, can often be greater than geographic differences. A skilled flyer, the western jackdaw can manoeuvre tightly as well as tumble and glide. It has characteristic jerky wing beats when flying, though these are not evident when birds are migrating.
Wind tunnel Wind tunnels are large tubes with air blowing through them which are used to replicate the interaction between air and an object flying through the air or moving along the ground. Researchers use wind tunnels to learn more about how an aircraft ...
experiments show that the preferred gliding speed is between per second and that the wingspan decreases as the bird flies faster. On the ground, western jackdaws have an upright posture and strut briskly, their short legs giving them a rapid gait. They feed with their heads held down or horizontally. Within its range, the western jackdaw is unmistakable; its short bill and grey nape are distinguishing features. From a distance, it can be confused with a rook (''Corvus frugilegus''), or when in flight, with a pigeon or
chough There are two species of passerine birds commonly called chough ( ) that constitute the genus ''Pyrrhocorax'' of the Corvidae (crow) family of birds. These are the red-billed chough (''Pyrrhocorax pyrrhocorax''), and the Alpine chough (or yello ...
. Cramp, p. 121. Flying western jackdaws are distinguishable from other corvids by their smaller size, faster and deeper wingbeats and proportionately narrower and less fingered wing tips. They also have shorter, thicker necks, much shorter bills and frequently fly in tighter flocks. They can be distinguished from choughs by their uniformly grey underwings and their black beaks and legs. The western jackdaw is very similar in morphology, behaviour, and calls to the Daurian jackdaw, with which its range overlaps in western Asia. Adults are readily distinguished, since the Daurian has a pied plumage, but immature birds are much more similar, both species having dark plumage and dark eyes. The Daurian tends to be darker, with a less contrasting nape than the Western.


Vocalisations

Western jackdaws are voluble birds. The main call, frequently given in flight, is a metallic and squeaky ''chyak-chyak'' or ''kak-kak''. This is a contact or greeting call. A feeding call made by adults to call young, or males when offering food to their mates, has been transcribed as ''kiaw'' or ''kyow''. Females in return give a more drawn out version when begging for food from males, written as ''kyaay'', ''tchaayk'' or ''giaaaa''. Cramp, p. 133. Perched birds often chatter together, and before settling for the night, large roosting flocks make a cackling noise. Western jackdaws also have a hoarse, drawn-out
alarm call In animal communication, an alarm signal is an antipredator adaptation in the form of signals emitted by social animals in response to danger. Many primates and birds have elaborate alarm calls for warning conspecifics of approaching predato ...
, ''arrrrr'' or ''kaaaarr'', used when warning of predators or when mobbing them. Nestlings begin making a soft ''cheep'' at about a week of age. As they grow, their voice becomes louder until their call is a penetrating screech around day 18. After this, the voice deepens and softens. Cramp, p. 134. From day 25, the young cease calling and become silent if they hear an unfamiliar noise. The European jackdaw can be trained to imitate human speech.


Distribution and habitat

The western jackdaw is found from Northwest Africa through all of Europe, except for the
subarctic The subarctic zone is a region in the Northern Hemisphere immediately south of the true Arctic, north of humid continental regions and covering much of Alaska, Canada, Iceland, the north of Scandinavia, Siberia, and the Cairngorms. Genera ...
north, and eastwards through
central Asia Central Asia, also known as Middle Asia, is a region of Asia that stretches from the Caspian Sea in the west to western China and Mongolia in the east, and from Afghanistan and Iran in the south to Russia in the north. It includes the fo ...
to the eastern
Himalayas The Himalayas, or Himalaya (; ; ), is a mountain range in Asia, separating the plains of the Indian subcontinent from the Tibetan Plateau. The range has some of the planet's highest peaks, including the very highest, Mount Everest. Over 10 ...
and
Lake Baikal Lake Baikal (, russian: Oзеро Байкал, Ozero Baykal ); mn, Байгал нуур, Baigal nuur) is a rift lake in Russia. It is situated in southern Siberia, between the federal subjects of Irkutsk Oblast to the northwest and the ...
. To the east, it occurs throughout
Turkey Turkey ( tr, Türkiye ), officially the Republic of Türkiye ( tr, Türkiye Cumhuriyeti, links=no ), is a transcontinental country located mainly on the Anatolian Peninsula in Western Asia, with a small portion on the Balkan Peninsula ...
, the
Caucasus The Caucasus () or Caucasia (), is a region between the Black Sea and the Caspian Sea, mainly comprising Armenia, Azerbaijan, Georgia, and parts of Southern Russia. The Caucasus Mountains, including the Greater Caucasus range, have historica ...
,
Iran Iran, officially the Islamic Republic of Iran, and also called Persia, is a country located in Western Asia. It is bordered by Iraq and Turkey to the west, by Azerbaijan and Armenia to the northwest, by the Caspian Sea and Turkmeni ...
,
Iraq Iraq,; ku, عێراق, translit=Êraq officially the Republic of Iraq, '; ku, کۆماری عێراق, translit=Komarî Êraq is a country in Western Asia. It is bordered by Turkey to Iraq–Turkey border, the north, Iran to Iran–Iraq ...
,
Afghanistan Afghanistan, officially the Islamic Emirate of Afghanistan,; prs, امارت اسلامی افغانستان is a landlocked country located at the crossroads of Central Asia and South Asia. Referred to as the Heart of Asia, it is borde ...
,
Pakistan Pakistan ( ur, ), officially the Islamic Republic of Pakistan ( ur, , label=none), is a country in South Asia. It is the world's List of countries and dependencies by population, fifth-most populous country, with a population of almost 24 ...
, and northwestern
India India, officially the Republic of India (Hindi: ), is a country in South Asia. It is the List of countries and dependencies by area, seventh-largest country by area, the List of countries and dependencies by population, second-most populous ...
. However, it is regionally extinct in
Malta Malta ( , , ), officially the Republic of Malta ( mt, Repubblika ta' Malta ), is an island country in the Mediterranean Sea. It consists of an archipelago, between Italy and Libya, and is often considered a part of Southern Europe. It lies ...
and
Tunisia ) , image_map = Tunisia location (orthographic projection).svg , map_caption = Location of Tunisia in northern Africa , image_map2 = , capital = Tunis , largest_city = capital , ...
. The range is vast, with an estimated global extent between . It has a large global population, with an estimated 15.6 to 45 million individuals in Europe alone. Censuses of bird populations in marginal uplands in Great Britain show that western jackdaws greatly increased in numbers between the 1970s and 2010, although this increase may be related to recovery from previous periods when they were regarded as pests. The UK population was estimated at 2.5 million individuals in 1998, up from 780,000 in 1970. Most populations are resident, but the northern and eastern populations are more migratory, relocating to wintering areas between September and November and returning between February and early May. Cramp, p. 124. Their range expands northwards into Russia to Siberia during summer and retracts in winter. They are vagrants to the
Faroe Islands The Faroe Islands ( ), or simply the Faroes ( fo, Føroyar ; da, Færøerne ), are a North Atlantic island group and an autonomous territory of the Kingdom of Denmark. They are located north-northwest of Scotland, and about halfway bet ...
, particularly in the winter and spring, and occasionally to
Iceland Iceland ( is, Ísland; ) is a Nordic island country in the North Atlantic Ocean and in the Arctic Ocean. Iceland is the most sparsely populated country in Europe. Iceland's capital and largest city is Reykjavík, which (along with its ...
. Elsewhere, western jackdaws congregate over winter in the Ural Valley in northwestern Kazakhstan, the northern Caspian, and the
Tian Shan The Tian Shan,, , otk, 𐰴𐰣 𐱅𐰭𐰼𐰃, , tr, Tanrı Dağı, mn, Тэнгэр уул, , ug, تەڭرىتاغ, , , kk, Тәңіртауы / Алатау, , , ky, Теңир-Тоо / Ала-Тоо, , , uz, Tyan-Shan / Tangritog‘ ...
region of western China. They are winter visitors to the Quetta Valley in western Pakistan, and are winter vagrants to
Lebanon Lebanon ( , ar, لُبْنَان, translit=lubnān, ), officially the Republic of Lebanon () or the Lebanese Republic, is a country in Western Asia. It is located between Syria to the north and east and Israel to the south, while Cyprus lie ...
, where they were first recorded in 1962. In
Syria Syria ( ar, سُورِيَا or سُورِيَة, translit=Sūriyā), officially the Syrian Arab Republic ( ar, الجمهورية العربية السورية, al-Jumhūrīyah al-ʻArabīyah as-Sūrīyah), is a Western Asian country loc ...
, they are winter vagrants and rare residents with some confirmed breeding taking place. The subspecies ''soemmerringii'' occurs in south-central Siberia and extreme northwestern China and is accidental to
Hokkaido is Japan, Japan's Japanese archipelago, second largest island and comprises the largest and northernmost Prefectures of Japan, prefecture, making up its own List of regions of Japan, region. The Tsugaru Strait separates Hokkaidō from Honshu; th ...
,
Japan Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the n ...
. A small number of western jackdaws reached northeastern North America in the 1980s and have been found from
Atlantic Canada Atlantic Canada, also called the Atlantic provinces (french: provinces de l'Atlantique), is the region of Eastern Canada comprising the provinces located on the Atlantic coast, excluding Quebec. The four provinces are New Brunswick, Newfoundla ...
to
Pennsylvania Pennsylvania (; ( Pennsylvania Dutch: )), officially the Commonwealth of Pennsylvania, is a state spanning the Mid-Atlantic, Northeastern, Appalachian, and Great Lakes regions of the United States. It borders Delaware to its southeast, ...
. They have also occurred as vagrants in
Gibraltar ) , anthem = " God Save the King" , song = "Gibraltar Anthem" , image_map = Gibraltar location in Europe.svg , map_alt = Location of Gibraltar in Europe , map_caption = United Kingdom shown in pale green , mapsize = , image_map2 = Gibr ...
,
Mauritania Mauritania (; ar, موريتانيا, ', french: Mauritanie; Berber: ''Agawej'' or ''Cengit''; Pulaar: ''Moritani''; Wolof: ''Gànnaar''; Soninke:), officially the Islamic Republic of Mauritania ( ar, الجمهورية الإسلامية ...
, and Saint Pierre and Miquelon, and one is reported to have been seen in
Egypt Egypt ( ar, مصر , ), officially the Arab Republic of Egypt, is a List of transcontinental countries, transcontinental country spanning the North Africa, northeast corner of Africa and Western Asia, southwest corner of Asia via a land bridg ...
. Western jackdaws inhabit wooded
steppe In physical geography, a steppe () is an ecoregion characterized by grassland plains without trees apart from those near rivers and lakes. Steppe biomes may include: * the montane grasslands and shrublands biome * the temperate gras ...
s, pastures, cultivated land, coastal cliffs, and towns. They thrive when forested areas are cleared and converted to fields and open areas. Habitats with a mix of large trees, buildings, and open ground are preferred; open fields are left to the rook, and more wooded areas to the
Eurasian jay The Eurasian jay (''Garrulus glandarius'') is a species of passerine bird in the crow family Corvidae. It has pinkish brown plumage with a black stripe on each side of a whitish throat, a bright blue panel on the upper wing and a black tail. The ...
(''Garrulus glandarius''). Along with other corvids such as the rook,
common raven The common raven (''Corvus corax'') is a large all-black passerine bird. It is the most widely distributed of all corvids, found across the Northern Hemisphere. It is a raven known by many names at the subspecies level; there are at least ...
(''Corvus corax''), and hooded crow (''C. cornix''), some western jackdaws spend the winter in urban parks; populations measured in three urban parks in
Warsaw Warsaw ( pl, Warszawa, ), officially the Capital City of Warsaw,, abbreviation: ''m.st. Warszawa'' is the capital and largest city of Poland. The metropolis stands on the River Vistula in east-central Poland, and its population is officiall ...
show increases from October to December, possibly due to western jackdaws migrating there from areas further north. The same data from Warsaw, collected from 1977 to 2003, showed that the wintering western jackdaw population had increased four-fold. The cause of the increase is unknown, but a reduction in the number of rooks may have benefited the species locally, or rooks overwintering in
Belarus Belarus,, , ; alternatively and formerly known as Byelorussia (from Russian ). officially the Republic of Belarus,; rus, Республика Беларусь, Respublika Belarus. is a landlocked country in Eastern Europe. It is bordered by ...
may have caused western jackdaws to relocate to Warsaw.


Behaviour

Generally wary of people in the forest or countryside, western jackdaws are much tamer in urban areas. Highly gregarious, western jackdaws are generally seen in flocks of varying sizes, though males and females pair-bond for life and pairs stay together within flocks. Flocks increase in size in autumn and birds congregate at dusk for
communal roosting Communal roosting is an animal behavior where a group of individuals, typically of the same species, congregate in an area for a few hours based on an external signal and will return to the same site with the reappearance of the signal. Environment ...
, with up to several thousand individuals gathering at one site. At
Uppsala Uppsala (, or all ending in , ; archaically spelled ''Upsala'') is the county seat of Uppsala County and the fourth-largest city in Sweden, after Stockholm, Gothenburg, and Malmö. It had 177,074 inhabitants in 2019. Located north of the ca ...
, Sweden, 40,000 birds have been recorded at a single winter roost with mated pairs often settling together for the night. Cramp, p. 129. Western jackdaws frequently congregate with hooded crows or rooks, the latter particularly when migrating or roosting. They have been recorded foraging with the common starling (''Sturnus vulgaris''),
Northern lapwing The northern lapwing (''Vanellus vanellus''), also known as the peewit or pewit, tuit or tew-it, green plover, or (in Ireland and Britain) pyewipe or just lapwing, is a bird in the lapwing subfamily. It is common through temperate Eurosiberia ...
(''Vanellus vanellus''), and
common gull The common gull or sea mew (''Larus canus'') is a medium-sized gull that breeds in the Palearctic, northern Europe. The closely related short-billed gull is sometimes included in this species, which may be known collectively as "mew gull". Ma ...
(''Larus canus'') in northwestern England. Flocks are targets of coordinated hunting by pairs of lanner falcons (''Falco biarmicus''), although larger groups are more able to elude the predators. Western jackdaws sometimes mob and drive off larger birds such as European magpies, common ravens, or
Egyptian vulture The Egyptian vulture (''Neophron percnopterus''), also called the white scavenger vulture or pharaoh's chicken, is a small Old World vulture and the only member of the genus ''Neophron''. It is widely distributed from the Iberian Peninsula and ...
s (''Neophron percnopterus''); one gives an alarm call which alerts its conspecifics to gather and attack as a group. Cramp, p. 132. Occasionally, a sick or injured western jackdaw is mobbed until it is killed. In his book '' King Solomon's Ring'', Konrad Lorenz described and analysed the complex social interactions in a western jackdaw flock that lived around his house in Altenberg,
Austria Austria, , bar, Östareich officially the Republic of Austria, is a country in the southern part of Central Europe, lying in the Eastern Alps. It is a federation of nine states, one of which is the capital, Vienna, the most populous ...
. He ringed them for identification and caged them in the winter to prevent their annual migration. He found that the birds have a linear hierarchical group structure, with higher-ranked individuals dominating lower-ranked birds, and pair-bonded birds sharing the same rank. Young males establish their individual status before pairing with females. Upon pairing, the female assumes the same social position as her partner. Unmated females are the lowest members in the pecking order, and are the last to have access to food and shelter. Lorenz noted one case in which a male, absent during the dominance struggles and pair bondings, returned to the flock, became the dominant male, and chose one of two unpaired females for a mate. This female immediately assumed a dominant position in the social hierarchy and demonstrated this by pecking others. According to Lorenz, the most significant factor in social behaviour was the immediate and intuitive grasp of the new hierarchy by each of the western jackdaws in the flock.


Social displays

Social hierarchy in western jackdaw flocks is determined by supplanting, fighting, and threat displays—several of which have been described. In the ''bill-up posture'', the western jackdaw tilts its bill and head upwards and sleeks its plumage. Indicating both appeasement and assertiveness, the posture is used by birds intending to enter feeding flocks. A ''bill-down posture'' is another commonly used agonistic behaviour. In this display, a bird lowers its bill and erects its nape and head feathers, and sometimes slightly lifts its wings. Western jackdaws often face off in this posture until one backs down or a fight ensues. In the ''forward-threat posture'', a bird holds its body horizontally and thrusts its head forwards. In intense versions, the bird ruffles its feathers and spreads or raises its tail and wings. This extreme is seen when facing off over nests or females. Cramp, p. 130. In the ''defensive-threat posture'', the bird lowers its head and bill, spreads its tail and ruffles its feathers. ''Supplanting'' is where one bird moves in and displaces another from a perch-site. The second bird usually retreats without resorting to a fight. Western jackdaws fight by launching themselves at each other feet-first and then wrestling with their feet intertwined and pecking at each other. Other individuals gather and call noisily. Cramp, p. 131. Western jackdaws entreat their partners to preen them by showing their nape and ruffling their head feathers. Birds mainly preen each other's head and neck. Known as ''allopreening'', this behaviour is almost always done between birds of a mated pair.


Breeding

Western jackdaws become sexually mature in their second year. Genetic analysis of pairs and offspring shows no evidence of extra-pair copulation and there is little evidence for couple separation even after multiple instances of reproductive failure. Some pairs do separate in the first few months, but almost all pairings of over six months' duration are lifelong, ending only when a partner dies. Cramp, p. 128. Widowed or separated birds fare badly, often being ousted from nests or territories and unable to rear broods alone. Western jackdaws usually breed in
colonies In modern parlance, a colony is a territory subject to a form of foreign rule. Though dominated by the foreign colonizers, colonies remain separate from the administration of the original country of the colonizers, the '' metropolitan state'' ...
with pairs collaborating to find a nest site, which they then defend from other pairs and predators during most of the year. They nest in cavities in trees or cliffs, in ruined or occupied buildings and in chimneys, the common feature being a sheltered site for the nest. The availability of suitable sites influences their presence in a locale. They may also use church steeples for nesting, a fact reported in verse by 18th century English poet
William Cowper William Cowper ( ; 26 November 1731 – 25 April 1800) was an English poet and Anglican hymnwriter. One of the most popular poets of his time, Cowper changed the direction of 18th-century nature poetry by writing of everyday life and sce ...
: Nest platforms can attain a great size. A mated pair usually constructs a nest by improving a crevice by dropping sticks into it; it is then built on top of the platform formed. This behaviour has led to the blocking of chimneys and even resulted in nests crashing down into fireplaces, sometimes with birds still on them. In his ''
The Natural History of Selborne ''The Natural History and Antiquities of Selborne'', or just ''The Natural History of Selborne'' is a book by English parson-naturalist Gilbert White (1720–1793). It was first published in 1789 by his brother Benjamin. It has been continuous ...
'', Gilbert White notes that western jackdaws used to nest in crevices beneath the
lintel A lintel or lintol is a type of beam (a horizontal structural element) that spans openings such as portals, doors, windows and fireplaces. It can be a decorative architectural element, or a combined ornamented structural item. In the case of ...
s of
Stonehenge Stonehenge is a prehistoric monument on Salisbury Plain in Wiltshire, England, west of Amesbury. It consists of an outer ring of vertical sarsen standing stones, each around high, wide, and weighing around 25 tons, topped by connec ...
, and describes an example of the bird using a rabbit burrow for nesting. The species has been recorded outcompeting the tawny owl (''Strix aluco'') for nest sites in the Netherlands. They can take over old nest sites of the
black woodpecker The black woodpecker (''Dryocopus martius'') is a large woodpecker that lives in mature forests across the northern Palearctic. It is the sole representative of its genus in that region. Its range is expanding. The black woodpecker is easily the ...
(''Dryocopus martius'') and stock dove (''Columba oenas''). Breeding colonies may also edge out those of the red-billed chough, but in turn be ousted by larger corvids such as the carrion crow, rook or magpie. Nests are lined with hair, wool, dead grass and many other materials. The eggs are a lighter colour than those of other corvids, being smooth, a glossy pale blue or blue-green with darker speckles ranging from dark brown to olive or grey-violet. Cramp, p. 135. Egg size and weight varies slightly between subspecies; those of subspecies ''monedula'' average and in weight, those of subspecies ''soemmerringii'' in size and in weight, and those of subspecies ''spermologus'' in size and in weight. Clutches usually contain 4 or 5 eggs, although a Slovakian study found clutch sizes ranging from 2 to 9 eggs. The eggs are incubated by the female for 17–18 days until hatching as naked altricial chicks, which are completely dependent on the adults for food. They fledge after 28–35 days, and the parents continue to feed them for another four weeks or so. Western jackdaws hatch asynchronously and incubation begins before clutch completion, which often leads to the death of the last-hatched young. If the supply of food is low, parental investment in the brood is kept to a minimum as little energy is wasted on feeding a chick that is unlikely to survive. Replacement clutches are very rarely laid in the event of clutch failure. The
great spotted cuckoo The great spotted cuckoo (''Clamator glandarius'') is a member of the cuckoo order of birds, the Cuculiformes, which also includes the roadrunners, the anis and the coucals. It is widely spread throughout Africa and the Mediterranean Basin. It ...
(''Clamator glandarius'') has been recorded as a
brood parasite Brood parasites are animals that rely on others to raise their young. The strategy appears among birds, insects and fish. The brood parasite manipulates a host, either of the same or of another species, to raise its young as if it were it ...
of the western jackdaw, depositing its eggs in their nests in Spain and Israel. Nest robbers include the common raven in Spain, tawny owl, and
least weasel The least weasel (''Mustela nivalis''), little weasel, common weasel, or simply weasel is the smallest member of the genus '' Mustela,'' family Mustelidae and order Carnivora. It is native to Eurasia, North America and North Africa, and has be ...
(''Mustela nivalis'') in England, and brown rat (''Rattus norvegicus'') in Finland. Cramp, p. 136. The European pine marten (''Martes martes'') raids isolated nests in Sweden but is less successful when nests are part of a colony.


Feeding

Foraging takes place mostly on the ground in open areas and to some extent in trees.
Landfill A landfill site, also known as a tip, dump, rubbish dump, garbage dump, or dumping ground, is a site for the disposal of waste materials. Landfill is the oldest and most common form of waste disposal, although the systematic burial of the wast ...
sites, bins, streets, and gardens are also visited, more often early in the morning when there are fewer people about. Various feeding methods are employed, such as jumping, pecking, clod-turning and scattering, probing the soil, and occasionally, digging. Flies around cow pats are caught by jumping from the ground or at times by dropping vertically from a few metres onto the cow pat.
Earthworm An earthworm is a terrestrial invertebrate that belongs to the phylum Annelida. They exhibit a tube-within-a-tube body plan; they are externally segmented with corresponding internal segmentation; and they usually have setae on all segments. T ...
s are not usually extracted from the ground by western jackdaws but are eaten from freshly ploughed soil. Jackdaws will ride on the backs of sheep and other mammals, seeking
tick Ticks (order Ixodida) are parasitic arachnids that are part of the mite superorder Parasitiformes. Adult ticks are approximately 3 to 5 mm in length depending on age, sex, species, and "fullness". Ticks are external parasites, living ...
s as well as actively gathering wool or hair for nests, and will catch flying ants in flight. Compared with other corvids, the western jackdaw spends more time exploring and turning over objects with its bill; it also has a straighter and less downturned bill and increased binocular vision which are advantageous for this foraging strategy. The western jackdaw tends to feed on small
invertebrate Invertebrates are a paraphyletic group of animals that neither possess nor develop a vertebral column (commonly known as a ''backbone'' or ''spine''), derived from the notochord. This is a grouping including all animals apart from the chorda ...
s up to in length that are found above ground, including various species of
beetle Beetles are insects that form the order Coleoptera (), in the superorder Endopterygota. Their front pair of wings are hardened into wing-cases, elytra, distinguishing them from most other insects. The Coleoptera, with about 400,000 describ ...
(particularly cockchafers of the genus '' Melolontha'', Cramp, p. 125. and
weevil Weevils are beetles belonging to the superfamily Curculionoidea, known for their elongated snouts. They are usually small, less than in length, and herbivorous. Approximately 97,000 species of weevils are known. They belong to several families, ...
larva A larva (; plural larvae ) is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle. ...
e and
pupa A pupa ( la, pupa, "doll"; plural: ''pupae'') is the life stage of some insects undergoing transformation between immature and mature stages. Insects that go through a pupal stage are holometabolous: they go through four distinct stages in thei ...
e.), '' Diptera'', and ''
Lepidoptera Lepidoptera ( ) is an order of insects that includes butterflies and moths (both are called lepidopterans). About 180,000 species of the Lepidoptera are described, in 126 families and 46 superfamilies, 10 percent of the total described speci ...
'' species, as well as snails and spiders. Also eaten are small rodents, bats, the eggs and chicks of birds, and carrion such as roadkill. Vegetable items consumed include farm grains (barley, wheat and oats), weed seeds, elderberries, acorns, and various cultivated fruits. Examination of the gizzards of western jackdaws shot in
Cyprus Cyprus ; tr, Kıbrıs (), officially the Republic of Cyprus,, , lit: Republic of Cyprus is an island country located south of the Anatolian Peninsula in the eastern Mediterranean Sea. Its continental position is disputed; while it is ...
in spring and summer revealed a diet of cereals (predominantly wheat) and insects (notably cicadas and
beetle Beetles are insects that form the order Coleoptera (), in the superorder Endopterygota. Their front pair of wings are hardened into wing-cases, elytra, distinguishing them from most other insects. The Coleoptera, with about 400,000 describ ...
s). The diet averages 84% plant material except when breeding, when the main food source is insects. A study in southern Spain examining western jackdaw pellets found that they contained significant amounts of
silicaceous Silicon dioxide, also known as silica, is an oxide of silicon with the chemical formula , most commonly found in nature as quartz and in various living organisms. In many parts of the world, silica is the major constituent of sand. Silica is one ...
and
calcareous Calcareous () is an adjective meaning "mostly or partly composed of calcium carbonate", in other words, containing lime or being chalky. The term is used in a wide variety of scientific disciplines. In zoology ''Calcareous'' is used as an ad ...
grit to aid digestion of vegetable food and supply dietary calcium. Opportunistic and highly adaptable, the western jackdaw varies its diet markedly depending on available food sources. Cramp, p. 127. They have been recorded taking eggs and nestlings from the nests of the skylark (''Alauda arvensis''),
Manx shearwater The Manx shearwater (''Puffinus puffinus'') is a medium-sized shearwater in the seabird family Procellariidae. The scientific name of this species records a name shift: Manx shearwaters were called Manks puffins in the 17th century. Puffin is a ...
(''Puffinus puffinus''),
razorbill The razorbill, razor-billed auk, or lesser auk (''Alca torda'') is a colonial seabird and the only extant member of the genus '' Alca'' of the family Alcidae, the auks. It is the closest living relative of the extinct great auk (''Pinguinis im ...
(''Alca torda''),
common murre The common murre or common guillemot (''Uria aalge'') is a large auk. It has a circumpolar distribution, occurring in low-Arctic and boreal waters in the North Atlantic and North Pacific. It spends most of its time at sea, only coming to land t ...
(''Uria aalge''),
grey heron The grey heron (''Ardea cinerea'') is a long-legged wading bird of the heron family, Ardeidae, native throughout temperate Europe and Asia and also parts of Africa. It is resident in much of its range, but some populations from the more north ...
(''Ardea cinerea''), rock pigeon (''Columba livia''), and Eurasian collared dove (''Streptopelia decaocto''). A field study of a large city dump on the outskirts of León in northwestern Spain showed that western jackdaws forage there in the early morning and at dusk, and engage in some degree of
kleptoparasitism Kleptoparasitism (etymologically, parasitism by theft) is a form of feeding in which one animal deliberately takes food from another. The strategy is evolutionarily stable when stealing is less costly than direct feeding, which can mean when ...
. The saker falcon (''Falco cherrug'') has been reported stealing food from western jackdaws on powerlines in Vojvodina in Serbia. Western jackdaws practice active food sharing – where the initiative for the transfer lies with the donor – with a number of individuals, regardless of sex or kinship. They also share more of a preferred food than a less preferred food. The active giving of food by most birds is found mainly in the context of parental care and courtship. Western jackdaws show much higher levels of active giving than has been documented for other species, including
chimpanzee The chimpanzee (''Pan troglodytes''), also known as simply the chimp, is a species of great ape native to the forest and savannah of tropical Africa. It has four confirmed subspecies and a fifth proposed subspecies. When its close relative t ...
s. The function of this behaviour is not fully understood, though it has been found to be detached from nutrition and compatible with hypotheses of mutualism, reciprocity and harassment avoidance. It has also been proposed that food sharing may be motivated by prestige enhancement.


Parasites and diseases

Western jackdaws have learned to peck open the foil caps of milk bottles left on the doorsteps after delivery by the milkman. The bacterium '' Campylobacter jejuni'' has been isolated from their beaks and cloacae so milk can become contaminated as they drink. This activity was linked to cases of ''Campylobacter''
gastroenteritis Gastroenteritis, also known as infectious diarrhea and gastro, is an inflammation of the gastrointestinal tract including the stomach and intestine. Symptoms may include diarrhea, vomiting, and abdominal pain. Fever, lack of energy, and dehydr ...
in
Gateshead Gateshead () is a large town in northern England. It is on the River Tyne's southern bank, opposite Newcastle to which it is joined by seven bridges. The town contains the Millennium Bridge, The Sage, and the Baltic Centre for Contemporary ...
in northeast England and led the Department of Health to suggest that milk from bottles which had been pecked open should be discarded. It was recommended that steps be taken to prevent birds from pecking open bottles in the future. An outbreak of a gastrointestinal illness in Spain which was causing mortalities in humans has been linked to western jackdaws. During a
post-mortem An autopsy (post-mortem examination, obduction, necropsy, or autopsia cadaverum) is a surgical procedure that consists of a thorough examination of a corpse by dissection to determine the cause, mode, and manner of death or to evaluate any d ...
on an affected bird, a polyomavirus was isolated from the
spleen The spleen is an organ found in almost all vertebrates. Similar in structure to a large lymph node, it acts primarily as a blood filter. The word spleen comes .
. The illness appeared to be a co-infection of this with ''
Salmonella ''Salmonella'' is a genus of rod-shaped (bacillus) Gram-negative bacteria of the family Enterobacteriaceae. The two species of ''Salmonella'' are '' Salmonella enterica'' and '' Salmonella bongori''. ''S. enterica'' is the type species and is ...
'' and the virus has been provisionally named the crow polyomavirus (CPyV).
Segmented filamentous bacteria Segmented filamentous bacteria or ''Candidatus'' Savagella are members of the gut microbiota of rodents, fish and chickens, and have been shown to potently induce immune responses in mice. They form a distinct lineage within the Clostridiaceae a ...
have been isolated from the small intestine of a western jackdaw, although their
pathogen In biology, a pathogen ( el, πάθος, "suffering", "passion" and , "producer of") in the oldest and broadest sense, is any organism or agent that can produce disease. A pathogen may also be referred to as an infectious agent, or simply a g ...
icity or role is unknown.


Pest control

The western jackdaw has been hunted as vermin, though not as heavily culled as other species of corvid. After a series of poor harvests in the early 1500s, introduced a Vermin Act in 1532 "ordeyned to dystroye Choughes (i.e. jackdaws), Crowes and Rokes" to protect grain crops from their predations. Western jackdaws were notorious as they also favoured fruit, especially cherries. This act was taken up in a piecemeal fashion, but passed the ''Act for the Preservation of Grayne'' in 1566 that was taken up with more vigour. The species was hunted for its threat to grain crops and for propensity for nesting in belfries until the mid-20th century. Particularly large numbers were culled in the county of
Norfolk Norfolk () is a ceremonial and non-metropolitan county in East Anglia in England. It borders Lincolnshire to the north-west, Cambridgeshire to the west and south-west, and Suffolk to the south. Its northern and eastern boundaries are the Nor ...
. Western jackdaws were also culled on game estates as they raid nests of other birds for eggs. In a 2003 dissertation on public opinion of corvids, Antonia Hereth notes that the German naturalist Alfred Brehm considered the western jackdaw to be a lovable bird, and did not describe any negative impacts of this species on agriculture. The western jackdaw is one of a very small number of birds that it is legal to use as a decoy or to trap in a cage in the United Kingdom. The other pest species that can be controlled by trapping are the crow, jay, magpie and rook. An authorised person must comply with the requirements of the
Wildlife and Countryside Act 1981 The Wildlife and Countryside Act 1981 is an Act of Parliament in the United Kingdom implemented to comply with European Council Directive 79/409/EEC on the conservation of wild birds. In short, the act gives protection to native species (especia ...
and does not need to show that the birds were a nuisance before trapping them. As of 2003 the western jackdaw was listed as a potential species for targeted hunting in the European Union Birds Directive, and hunting has been encouraged by German hunting associations. Permission to shoot western jackdaws in spring and summer exists in Cyprus as they are thought (incorrectly) to prey on gamebirds.


Cultural depictions and folklore

An ancient Greek and Roman adage runs "The swans will sing when the jackdaws are silent", meaning that educated or wise people will speak only after the foolish have become quiet. In
Ancient Greek Ancient Greek includes the forms of the Greek language used in ancient Greece and the ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Dark Ages (), the Archaic pe ...
folklore Folklore is shared by a particular group of people; it encompasses the traditions common to that culture, subculture or group. This includes oral traditions such as tales, legends, proverbs and jokes. They include material culture, rangin ...
, a jackdaw can be caught with a dish of oil. A narcissistic creature, it falls in while looking at its own reflection. The mythical Princess Arne Sithonis was bribed with gold by King Minos of
Crete Crete ( el, Κρήτη, translit=, Modern: , Ancient: ) is the largest and most populous of the Greek islands, the 88th largest island in the world and the fifth largest island in the Mediterranean Sea, after Sicily, Sardinia, Cyprus, ...
, and was punished by the gods for her greed by being transformed into an equally avaricious jackdaw, who still seeks shiny things. The Roman poet
Ovid Pūblius Ovidius Nāsō (; 20 March 43 BC – 17/18 AD), known in English as Ovid ( ), was a Augustan literature (ancient Rome), Roman poet who lived during the reign of Augustus. He was a contemporary of the older Virgil and Horace, with whom ...
described jackdaws as harbingers of rain in his poetic work '' Amores''. Pliny notes how the Thessalians,
Illyrians The Illyrians ( grc, Ἰλλυριοί, ''Illyrioi''; la, Illyrii) were a group of Indo-European-speaking peoples who inhabited the western Balkan Peninsula in ancient times. They constituted one of the three main Paleo-Balkan populations, a ...
, and
Lemnian The Lemnian language was spoken on the island of Lemnos, Greece, in the second half of the 6th century BC. It is mainly attested by an inscription found on a funerary stele, termed the Lemnos stele, discovered in 1885 near Kaminia. Fragments of ...
s cherished jackdaws for destroying grasshoppers' eggs. The Veneti are fabled to have bribed the jackdaws to spare their crops. In some cultures, a jackdaw on the roof is said to predict a new arrival; alternatively, a jackdaw settling on the roof of a house or flying down a chimney is an omen of death, and coming across one is considered a bad omen. A jackdaw standing on the vanes of a cathedral tower is said to foretell rain. The 12th-century historian William of Malmesbury records the story of a woman who, upon hearing a jackdaw chattering "more loudly than usual," grew pale and became fearful of suffering a "dreadful calamity", and that "while yet speaking, the messenger of her misfortunes arrived". Czech superstition formerly held that if jackdaws are seen quarreling, war will follow, and that jackdaws will not build nests at Sázava after being banished by Saint Procopius. The jackdaw was considered sacred in Welsh folklore as it nested in church steeples – it was shunned by the Devil because of its choice of residence. Nineteenth century belief in
the Fens The Fens, also known as the , in eastern England are a naturally marshy region supporting a rich ecology and numerous species. Most of the fens were drained centuries ago, resulting in a flat, dry, low-lying agricultural region supported by a ...
held that seeing a jackdaw on the way to a wedding was a good omen for a bride. The jackdaw is featured on the
Ukrainian Ukrainian may refer to: * Something of, from, or related to Ukraine * Something relating to Ukrainians, an East Slavic people from Eastern Europe * Something relating to demographics of Ukraine in terms of demography and population of Ukraine * So ...
town of Halych's ancient coat of arms, the town's name allegedly being derived from the East Slavic word for the bird. In ''
The Book of Laughter and Forgetting ''The Book of Laughter and Forgetting'' ( cs, Kniha smíchu a zapomnění, Kniha smíchu a zapomnění) is a novel by Milan Kundera, published in France in 1979. It is composed of seven separate narratives united by some common themes. The boo ...
'' (1979),
Milan Kundera Milan Kundera (, ; born 1 April 1929) is a Czech writer who went into exile in France in 1975, becoming a naturalised French citizen in 1981. Kundera's Czechoslovak citizenship was revoked in 1979, then conferred again in 2019. He "sees himsel ...
notes that
Franz Kafka Franz Kafka (3 July 1883 – 3 June 1924) was a German-speaking Bohemian novelist and short-story writer, widely regarded as one of the major figures of 20th-century literature. His work fuses elements of realism and the fantastic. It typ ...
's father Hermann had a sign in front of his shop with a jackdaw painted next to his name, since "kavka" means ''jackdaw'' in Czech. Alex K Halych 2.svg, Coat of Arms of the Principality of Halych Recueil_d'armoiries_polonaises_-_COA_of_Halych_Land_crop2.png, Coat of Arms of Halych Land Alex_K_Grundwald_flags_1410-07.svg, Flag of Halych land at the
Battle of Grunwald The Battle of Grunwald, Battle of Žalgiris or First Battle of Tannenberg was fought on 15 July 1410 during the Polish–Lithuanian–Teutonic War. The alliance of the Crown of the Kingdom of Poland and the Grand Duchy of Lithuania, led respec ...
1410 Coat of Arms of Ivano-Frankivsk Oblast.svg, Coat of Arms of
Ivano-Frankivsk Oblast Ivano-Frankivsk Oblast ( uk, Іва́но-Франкі́вська о́бласть, translit=Ivano-Frankivska oblast), also referred to as Ivano-Frankivshchyna ( uk, Іва́но-Франкі́вщина), is an oblast (region) in western Ukraine ...


References


Works cited

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External links


Jackdaw videos, photos and sounds
on the Internet Bird Collection
(PDF; 2.1 MB) Ageing and sexing by Javier Blasco-Zumeta & Gerd-Michael Heinze


{{Authority control western jackdaw Birds of Eurasia Birds of Europe western jackdaw western jackdaw Taxobox binomials not recognized by IUCN