The Asian koel (''Eudynamys scolopaceus'') is a member of the
cuckoo
Cuckoos are birds in the Cuculidae ( ) family, the sole taxon in the order Cuculiformes ( ). The cuckoo family includes the common or European cuckoo, roadrunners, koels, malkohas, couas, coucals, and anis. The coucals and anis are somet ...
family
Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...
of
bird
Birds are a group of warm-blooded vertebrates constituting the class (biology), class Aves (), characterised by feathers, toothless beaked jaws, the Oviparity, laying of Eggshell, hard-shelled eggs, a high Metabolism, metabolic rate, a fou ...
s, the
Cuculidae. It is found in the
Indian Subcontinent
The Indian subcontinent is a physiographic region of Asia below the Himalayas which projects into the Indian Ocean between the Bay of Bengal to the east and the Arabian Sea to the west. It is now divided between Bangladesh, India, and Pakista ...
,
Pakistan
Pakistan, officially the Islamic Republic of Pakistan, is a country in South Asia. It is the List of countries and dependencies by population, fifth-most populous country, with a population of over 241.5 million, having the Islam by country# ...
,
China
China, officially the People's Republic of China (PRC), is a country in East Asia. With population of China, a population exceeding 1.4 billion, it is the list of countries by population (United Nations), second-most populous country after ...
, and Southeast Asia. It forms a
superspecies
In biology, a species complex is a group of closely related organisms that are so similar in appearance and other features that the boundaries between them are often unclear. The taxa in the complex may be able to hybridize readily with each oth ...
with the closely related
black-billed koel
The black-billed koel (''Eudynamys melanorhynchus'') is a species of cuckoo in the family Cuculidae. It is Endemism, endemic to forest and woodland on the Indonesian islands of Sulawesi, Sula Islands, Sula, Banggai Island, Banggai, Togian Island ...
s, and
Pacific koels which are sometimes treated as
subspecies
In Taxonomy (biology), biological classification, subspecies (: subspecies) is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (Morphology (biology), morpholog ...
. The Asian koel like many of its related cuckoo kin is a
brood parasite
Brood may refer to:
Nature
* Brood, a collective term for offspring
* Brooding, the incubation of bird eggs by their parents
* Bee brood, the young of a beehive
* Individual broods of North American periodical cicadas:
** Brood X, the largest ...
that lays its eggs in the nests of
crows
The Common Remotely Operated Weapon Station (CROWS) is a series of remote weapon stations used by the US military on its armored vehicles and ships. It allows weapon operators to engage targets without leaving the protection of their vehicle. ...
and other hosts, who raise its young. They are unusual among the cuckoos in being largely
frugivorous
A frugivore ( ) is an animal that thrives mostly on raw fruits or succulent fruit-like produce of plants such as roots, shoots, nuts and seeds. Approximately 20% of mammalian herbivores eat fruit. Frugivores are highly dependent on the abundance ...
as adults.
The name ''koel'' is echoic in origin with several language variants. The bird is a widely used symbol in Indian and Nepali poetry.
Taxonomy
In 1747, the English naturalist
George Edwards included an illustration and a description of an Asian koel in the second volume of his ''A Natural History of Uncommon Birds'' book. He used the English name "The Brown and Spotted Indian Cuckow". Edwards based his hand-coloured etching on a specimen from Bengal that belonged to the London silk-pattern designer and naturalist
Joseph Dandridge. When in 1758 the Swedish naturalist
Carl Linnaeus
Carl Linnaeus (23 May 1707 – 10 January 1778), also known after ennoblement in 1761 as Carl von Linné,#Blunt, Blunt (2004), p. 171. was a Swedish biologist and physician who formalised binomial nomenclature, the modern system of naming o ...
updated his ''
Systema Naturae
' (originally in Latin written ' with the Orthographic ligature, ligature æ) is one of the major works of the Sweden, Swedish botanist, zoologist and physician Carl Linnaeus (1707–1778) and introduced the Linnaean taxonomy. Although the syste ...
'' for the
tenth edition, he placed the Asian koel with the other cuckoos in the
genus
Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...
''
Cuculus
''Cuculus'' is a genus of cuckoos which has representatives in most of the Old World, although the greatest diversity is in tropical southern and southeastern Asia.
Taxonomy
The genus ''Cuculus'' was introduced in 1758 by the Swedish naturalist ...
''. Linnaeus included a brief description, coined the
binomial name
In taxonomy, binomial nomenclature ("two-term naming system"), also called binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, both of which use Latin grammatical forms, altho ...
''Cuculus scolopaceus'' and cited Edwards' work. The Asian koel is now placed in the
genus
Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...
''
Eudynamys'' that was introduced in 1827 by the English naturalists
Nicholas Vigors and
Thomas Horsfield
Thomas Horsfield (May 12, 1773 – July 24, 1859) was an American physician and natural history, naturalist who worked extensively in Indonesia, describing numerous species of plants and animals from the region. He was later a curator of the Eas ...
.
The genus name ''Eudynamys'' combines the
Ancient Greek
Ancient Greek (, ; ) includes the forms of the Greek language used in ancient Greece and the classical antiquity, ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Greek ...
''eu'' meaning "fine" with ''dunamis'' meaning "power" or "strength". The specific epithet ''scolopaceus'' is
Modern Latin
Neo-LatinSidwell, Keith ''Classical Latin-Medieval Latin-Neo Latin'' in ; others, throughout. (also known as New Latin and Modern Latin) is the style of written Latin used in original literary, scholarly, and scientific works, first in Italy d ...
meaning "snipe-like" from Latin ''scolopax'' meaning "snipe" or "woodcock".
The species has variations within its wide range with several island populations and a number of taxonomic variations have been suggested. The
black-billed koel
The black-billed koel (''Eudynamys melanorhynchus'') is a species of cuckoo in the family Cuculidae. It is Endemism, endemic to forest and woodland on the Indonesian islands of Sulawesi, Sula Islands, Sula, Banggai Island, Banggai, Togian Island ...
(''E. melanorhynchus'') of the
Sulawesi
Sulawesi ( ), also known as Celebes ( ), is an island in Indonesia. One of the four Greater Sunda Islands, and the List of islands by area, world's 11th-largest island, it is situated east of Borneo, west of the Maluku Islands, and south of Min ...
region and the
Pacific koel of Australasia are sometimes considered
conspecific
Biological specificity is the tendency of a characteristic such as a behavior or a biochemical variation to occur in a particular species.
Biochemist Linus Pauling stated that "Biological specificity is the set of characteristics of living organism ...
with the Asian koel in which case the "combined" species is known as the
common koel. Due to differences in
plumage
Plumage () is a layer of feathers that covers a bird and the pattern, colour, and arrangement of those feathers. The pattern and colours of plumage differ between species and subspecies and may vary with age classes. Within species, there can b ...
, colour of bill and voice, the three are increasingly treated as separate species. Alternatively, only the black-billed koel has been considered as a separate species, or the Asian koel has included all subspecies otherwise included in the Pacific koel, except for the subspecies breeding in Australia, which then has the name
Australian koel (''E. cyanocephalus'').
The Asian koel has several geographic forms that have well marked plumage differences or have been geographically isolated with little gene flow. The following is a list of named subspecies with their distributions and
synonyms
A synonym is a word, morpheme, or phrase that means precisely 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 a ...
as given by Payne:
*''E. s. scolopaceus'' (
Linnaeus
Carl Linnaeus (23 May 1707 – 10 January 1778), also known after ennoblement in 1761 as Carl von Linné,#Blunt, Blunt (2004), p. 171. was a Swedish biologist and physician who formalised binomial nomenclature, the modern system of naming o ...
,
1758
Events
January–March
* January 1 – Swedish biologist Carl Linnaeus (Carl von Linné) publishes in Stockholm the first volume (''Animalia'') of the 10th edition of ''Systema Naturae'', the starting point of modern zoologic ...
) – Pakistan, India,
Nepal
Nepal, officially the Federal Democratic Republic of Nepal, is a landlocked country in South Asia. It is mainly situated in the Himalayas, but also includes parts of the Indo-Gangetic Plain. It borders the Tibet Autonomous Region of China Ch ...
, Bangladesh, Sri Lanka,
Laccadives and
Maldives
The Maldives, officially the Republic of Maldives, and historically known as the Maldive Islands, is an Archipelagic state, archipelagic country in South Asia located in the Indian Ocean. The Maldives is southwest of Sri Lanka and India, abou ...
*''E. s. chinensis''
Cabanis and
Heine
Heine is both a surname and a given name of German origin. People with that name include:
People with the surname
* Albert Heine (1867–1949), German actor
* Alice Heine (1858–1925), American-born princess of Monaco
* Armand Heine (1818–1883) ...
, 1863 – Southern China and
Indochina
Mainland Southeast Asia (historically known as Indochina and the Indochinese Peninsula) is the continental portion of Southeast Asia. It lies east of the Indian subcontinent and south of Mainland China and is bordered by the Indian Ocean to th ...
, except the
Thai-Malay Peninsula
*''E. s. harterti''
Ingram, C 1912 –
Hainan
Hainan is an island provinces of China, province and the southernmost province of China. It consists of the eponymous Hainan Island and various smaller islands in the South China Sea under the province's administration. The name literally mean ...
*''E. s. malayana'' Cabanis and Heine, 1863 –
Thai-Malay Peninsula,
Lesser Sundas and
Greater Sundas, except
Sulawesi
Sulawesi ( ), also known as Celebes ( ), is an island in Indonesia. One of the four Greater Sunda Islands, and the List of islands by area, world's 11th-largest island, it is situated east of Borneo, west of the Maluku Islands, and south of Min ...
. May include the race ''dolosa'' described from the
Andaman and
Nicobar Islands
The Nicobar Islands are an archipelago, archipelagic island chain in the eastern Indian Ocean. They are located in Southeast Asia, northwest of Aceh on Sumatra, and separated from Thailand to the east by the Andaman Sea. Located southeast of t ...
*''E. s. mindanensis'' (Linnaeus, 1766) – (includes ''E. s. paraguena'')
( Hachisuka, 1934) from
Palawan
Palawan (, ), officially the Province of Palawan (; ), is an archipelagic province of the Philippines that is located in the region of Mimaropa. It is the largest province in the country in terms of total area of . The capital and largest c ...
, and ''E. s. corvina''
(Stresemann Stresemann is a German family name which may refer to:
* Christina Stresemann (born 1957), German judge; daughter of Wolfgang Stresemann
* Erwin Stresemann (1889 – 1972), German ornithologist
* Gustav Stresemann
Gustav Ernst Stresemann (; 10 ...
, 1931) from
Halmahera
Halmahera, formerly known as Jilolo, Gilolo, or Jailolo, is the largest island in the Maluku Islands. It is part of the North Maluku Provinces of Indonesia, province of Indonesia, and Sofifi, the capital of the province, is located on the west coa ...
, the Philippines (including Palawan and the
Babuyan Islands
The Babuyan Islands ( ), also known as the Babuyan Group of Islands, is an archipelago in the Philippines, located in the Luzon Strait north of the main island of Luzon and south of Taiwan. The archipelago consists of five major islands and thei ...
), islands between
Mindanao
Mindanao ( ) is the List of islands of the Philippines, second-largest island in the Philippines, after Luzon, and List of islands by population, seventh-most populous island in the world. Located in the southern region of the archipelago, the ...
and Sulawesi, and
North Maluku
North Maluku (; ) is a province of Indonesia. It covers the northern part of the Maluku Islands, bordering the Pacific Ocean to the north, the Halmahera Sea to the east, the Molucca Sea to the west, and the Seram Sea to the south. It shares marit ...
, except the
Sula Islands
Description

The Asian koel is a large and long-tailed cuckoo measuring and weighing .
[''CRC Handbook of Avian Body Masses'' by John B. Dunning Jr. (ed.). CRC Press (1992), .] The male of the nominate race is glossy bluish-black, with a pale greenish grey bill, the iris is crimson, and it has grey legs and feet. The female of the nominate race is brownish on the crown and has rufous streaks on the head. The back, rump and wing coverts are dark brown with white and buff spots. The underparts are whitish, but is heavily striped. The other subspecies differ in colouration and size.
The upper plumage of young birds is more like that of the male and they have a black beak.
They are very vocal during the breeding season (March to August in the Indian Subcontinent), with a range of different calls. The familiar song of the male is a repeated ''koo-Ooo''. The female makes a shrill ''kik-kik-kik...'' call. Calls vary across populations.
They show a pattern of
moult
In biology, moulting (British English), or molting (American English), also known as sloughing, shedding, or in many invertebrates, ecdysis, is a process by which an animal casts off parts of its body to serve some beneficial purpose, either at ...
that differs from those of other parasitic cuckoos. The outer
primaries
Primary elections or primaries are elections held to determine which candidates will run in an upcoming general election. In a partisan primary, a political party selects a candidate. Depending on the state and/or party, there may be an "open pri ...
show a transilient (alternating) ascending moult (P9-7-5-10-8-6) while the inner primaries are moulted in stepwise descending order (1-2-3-4).(Payne citing Stresemann and Stresemann 1961
)
Distribution and habitat
The Asian koel is a bird of light woodland and cultivation. It is a mainly resident breeder in tropical southern Asia from Iran, Pakistan, India, Bangladesh, Maldives, and Sri Lanka to southern China and the Greater Sundas. They have great potential in colonizing new areas, and were among the pioneer birds to colonize the volcanic island of
Krakatau. They first arrived in Singapore in the 1980s and became very common birds.
Some populations may make long-distance movements being found in places like Australia.
Behaviour

The Asian koel is a
brood parasite
Brood may refer to:
Nature
* Brood, a collective term for offspring
* Brooding, the incubation of bird eggs by their parents
* Bee brood, the young of a beehive
* Individual broods of North American periodical cicadas:
** Brood X, the largest ...
, and lays its single
egg
An egg is an organic vessel grown by an animal to carry a possibly fertilized egg cell (a zygote) and to incubate from it an embryo within the egg until the embryo has become an animal fetus that can survive on its own, at which point the ...
in the nests of a variety of birds, including the
jungle crow,
and
house crow
The house crow (''Corvus splendens''), also known as the Indian, greynecked, Ceylon or Colombo crow, is a common bird of the crow family that is of Asian origin but now found in many parts of the world, where they arrived assisted by shipping. I ...
. In Sri Lanka before 1880 it was only known to parasitize the jungle crow, later shifting to the house crow. A study in India found 5% of ''
Corvus splendens'' and 0.5% of ''
Corvus macrorhynchos'' nests parasitized.
In Bangladesh, they parasitise
long-tailed shrike (''Lanius schach''),
common myna
The common myna or Indian myna (''Acridotheres tristis''), sometimes spelled mynah, is a bird in the Family (biology), family Sturnidae, native to Asia. An omnivorous open woodland bird with a strong territorial instinct, the common myna has ada ...
(''Acridotheres tristis'') and house crows (''Corvus splendens'') at about 35.7, 31.2 and 10.8% rates respectively. Host nests at low heights and nearer to fruit trees tended to be preferred by koels. In southern Thailand and the
Malay Peninsula
The Malay Peninsula is located in Mainland Southeast Asia. The landmass runs approximately north–south, and at its terminus, it is the southernmost point of the Asian continental mainland. The area contains Peninsular Malaysia, Southern Tha ...
, koels have shifted host from crows to mynas (''
Acridotheres
''Acridotheres'' is a genus of starlings, the "typical" mynas, which are tropical members of the family Sturnidae.
Distribution
This genus has representatives in tropical southern Asia from Iran east to southern China and Indonesia. Two species ...
'' sp.) as the latter became more common in the late 1900s.
A record exists of
black drongo raising a koel, and other hosts recorded include the
European magpie
The Eurasian magpie or common magpie (''Pica pica'') is a resident breeding bird throughout the northern part of the Eurasian continent. It is one of several birds in the crow family (corvids) designated magpies, and belongs to the Holarctic ra ...
and possibly the
black-headed oriole. In the Philippines, Asian Koels have been found to parasitize the cavity nest of Coletos (''Sarcops calvus''). Males may distract the hosts so that the female gets a chance to lay an egg in the nest. More often however, the female visits the nest of the host alone.
The koel is not known to lay eggs in an empty host nest and a study in Pakistan found that the first koel eggs were laid, on average, within one and half days of the laying of the host's first egg. The chicks of the koel hatched about 3 days ahead of the host chicks.
Koels usually lay only an egg or two in a single nest but as many as seven to eleven eggs have been reported from some host nests. A female may remove a host egg before laying. Eggs hatch in 12 to 14 days. The young koel does not always push out eggs or evict the host chicks, and initially calls like a crow. The young fledge in 20 to 28 days.
Unlike some other cuckoos, the young do not attempt to kill the host chicks, a trait that is shared with the
channel-billed cuckoos which are also largely frugivorous as adults. Some scholars,
Rebecca Kilner in particular, have suggested that koels, like some other brood parasites, do not evict the host chicks as a result of higher costs which might outweigh the benefits of evicting nestmates.
A small parasite may not be able to evict large host eggs or chicks from a deep Corvid nest without risking starvation and possibly accidental self-eviction. An alternative hypothesis that retaining host chicks might benefit the koel chicks did not gain much support.
Adult female parents have been known to feed young koels in the nests of the hosts, a behaviour seen in some other brood parasitic species as well. Adult males have however not been noted to feed fledglings.
The Asian koel is omnivorous, consuming a variety of insects, caterpillars, eggs and small
vertebrate
Vertebrates () are animals with a vertebral column (backbone or spine), and a cranium, or skull. The vertebral column surrounds and protects the spinal cord, while the cranium protects the brain.
The vertebrates make up the subphylum Vertebra ...
s. Adults feed mainly on
fruit
In botany, a fruit is the seed-bearing structure in flowering plants (angiosperms) that is formed from the ovary after flowering.
Fruits are the means by which angiosperms disseminate their seeds. Edible fruits in particular have long propaga ...
. They will sometimes defend fruiting trees that they forage in and chase away other frugivores. They have been noted to be especially important in the
dispersal of the sandalwood tree (''
Santalum album
''Santalum album'' is a small tropical tree, and the traditional source of sandalwood oil. It is native to Indonesia (Java and the Lesser Sunda Islands), the Philippines, and Western Australia. It is commonly known as the true sandalwood, white ...
'') in India. Large seeded fruits are sometimes quickly regurgitated near the parent tree while small seeded fruits are ingested and are likely to be deposited at greater distances from the parent tree. They have a large gape and are capable of swallowing large fruits including the hard fruit of palms such as ''
Arenga'' and ''
Livistona''.
They have been known to occasionally take eggs of small birds.
They feed on the fruits of ''
Cascabela thevetia
''Cascabela thevetia'' (Synonym (taxonomy), synonym ''Thevetia peruviana'') is a poisonous plant native throughout Mexico and in Central America, and cultivated widely as an ornamental. It is a relative of ''Nerium oleander'', giving it a common ...
'' which are known to be toxic to mammals.
A number of parasites of the species have been described, including malaria-like protozoa, lice and nematodes.
In culture
The word "koel" is
onomatopoeic
Onomatopoeia (or rarely echoism) is a type of word, or the process of creating a word, that phonetically imitates, resembles, or suggests the sound that it describes. Common onomatopoeias in English include animal noises such as ''oink'', '' ...
in origin. The Sanskrit name of "Kokila" and words in several Indian languages are similarly echoic.
Being familiar birds with loud calls, references to them are common in folklore, myth and poetry. It is traditionally held in high regard for its song and revered in the
Manusmriti
The ''Manusmṛti'' (), also known as the ''Mānava-Dharmaśāstra'' or the Laws of Manu, is one of the many legal texts and constitutions among the many ' of Hinduism.
Over fifty manuscripts of the ''Manusmriti'' are now known, but the earli ...
, with a decree protecting them from harm. The
Vedas
FIle:Atharva-Veda samhita page 471 illustration.png, upright=1.2, The Vedas are ancient Sanskrit texts of Hinduism. Above: A page from the ''Atharvaveda''.
The Vedas ( or ; ), sometimes collectively called the Veda, are a large body of relig ...
, Sanskrit literature dated to about 2000 BC referred to it as ''Anya-Vapa'' which has been translated as "that which was raised by others" (or "sown for others to reap"). This has been interpreted as the earliest written reference to brood parasitism.
It has been chosen as the state bird by the Indian union territory of
Puducherry.
These birds were once very popular in India as cagebirds. Feeding even on boiled rice, these hardy birds lived in captivity for as long as 14 years.
In Sri Lanka, Koel has an unbreakable bond with the
Sinhalese New Year
Sinhalese New Year, generally known as Aluth Awurudda () in Sri Lanka, is a Sri Lankan holiday that celebrates the traditional New Year of the Sinhalese people. The timing of the Sinhala New Year coincides with the new year celebrations of ma ...
as according to the beliefs, the call of koels signify the arrival of the new year in the month of April.
References
Further reading
* Eates, KR (1938) The status of the Koel (''Eudynamys scolopaceus'' L.) in Sind. ''Journal of the Bombay Natural History Society'' 40(2):328.
* Jose, TV (1980) Koels. ''
Newsletter for Birdwatchers
''Newsletter for Birdwatchers'' is an Indian periodical of ornithology and birdwatching founded in 1960 by Zafar Futehally, who edited it until 2003. It was initially mimeographed and distributed to a small number of subscribers each month. It is ...
'' . 20(4), 17.
* Menon, G.K.; Shah, R.V. (1979) Adaptive features in juvenal plumage pattern of the Indian Koel ''Eudynamys scolopacea'': host mimesis and hawk-pattern. ''Journal of the Yamashina Institute for Ornithology'' 11(2):87–95
* Neelakantan, KK (1980) The breeding of the Indian Koel ''Eudynamys scolopacea''. ''
Newsletter for Birdwatchers
''Newsletter for Birdwatchers'' is an Indian periodical of ornithology and birdwatching founded in 1960 by Zafar Futehally, who edited it until 2003. It was initially mimeographed and distributed to a small number of subscribers each month. It is ...
'' . 20(1):7.
* Parasharya, BM (1985) Comments on eye color in the Koel ''Eudynamys scolopacea''. ''
Newsletter for Birdwatchers
''Newsletter for Birdwatchers'' is an Indian periodical of ornithology and birdwatching founded in 1960 by Zafar Futehally, who edited it until 2003. It was initially mimeographed and distributed to a small number of subscribers each month. It is ...
'' . 25(1–2), 11–12.
* Ray-Chaudhuri, R. (1967) Mitotic and meiotic chromosomes of the koel ''Eudynamys scolopacea scolopacea''. ''Nucleus'' 10: 179–189. (Study notes that the W chromosome is the 6th largest one and has the centromere in a subterminal position.)
* Ryall C (2003) Mimicry of a crow chick by an Asian koel ''Eudynamys scolopacea'' as a defence against attack by house crows Corvus splendens. ''Journal of the Bombay Natural History Society'' 100(1):136–137
* Santharam, V (1979) Crows feeding young koel. ''
Newsletter for Birdwatchers
''Newsletter for Birdwatchers'' is an Indian periodical of ornithology and birdwatching founded in 1960 by Zafar Futehally, who edited it until 2003. It was initially mimeographed and distributed to a small number of subscribers each month. It is ...
'' . 19(7), 4.
* Sarkar AK, Maitra SK, Midya T. (1976) Histological, histochemical and biochemical effects of cadmium chloride in female koel (''Eudynamys scolopacea''). ''Acta Histochem''. 57(2):205-11.
* Sarkar AK, Maitra SK, Midya T. (1977) Effects of reserpine on female reproductive organs of the Indian koel ''Eudynamys scolopacea scolopacea'' (L). ''Indian Journal of Experimental Biology'' 15(5):349-51.
{{Taxonbar , from=Q798401
Brood parasites
Asian koel
Birds of Asia
Birds of Indomalaya
Asian koel
Asian koel
Symbols of Jharkhand