Cuculus canorus
[order] Cuculiformes | [family] Cuculidae | [latin] Cuculus canorus | [UK] Cuckoo | [FR] Coucou gris | [DE] Kuckuck | [ES] Cuco Europeo | [IT] Cuculo eurasiatico | [NL] Koekoek | [IRL] Cuach
Measurements
spanwidth min.: 54 cm
spanwidth max.: 60 cm
size min.: 32 cm
size max.: 36 cm
Breeding
incubation min.: 11 days
incubation max.: 12 days
fledging min.: 17 days
fledging max.: 17 days
broods 15
eggs min.: 1
eggs max.: 25
Status: Widespread summer visitor to Ireland from April to August.
Conservation Concern: Green-listed in Ireland. The European population is currently evaluated as secure.
Identification: Despite its obvious song, relatively infrequently seen. In flight, can be mistaken for a bird of prey such as Sparrowhawk, but has rapid wingbeats below the horizontal plane - ie. the wings are not raised above the body. Adult male Cuckoos are a uniform grey on the head, neck, back, wings and tail. The underparts are white with black barring. Adult females can appear in one of two forms. The so-called grey-morph resembles the adult male plumage, but has throat and breast barred black and white with yellowish wash. The rufous-morph has the grey replaced by rufous, with strong black barring on the wings, back and tail. Juvenile Cuckoos resemble the female rufous-morph, but are darker brown above.
Similar Species: Sparrowhawk
Call: The song is probably one of the most recognisable and well-known of all Irish bird species. The male gives a distinctive “wuck-oo”, which is occasionally doubled “wuck-uck-ooo”. The female has a distinctive bubbling “pupupupu”. The song period is late April to late June.
Diet: Mainly caterpillars and other insects.
Breeding: Widespread in Ireland, favouring open areas which hold their main Irish host species – Meadow Pipit. Has a remarkable breeding biology unlike any other Irish breeding species.
Wintering: Cuckoos winter in central and southern Africa.
To minimise the chance of being recognised and thus attacked by the birds they are trying to parasitize, female cuckoos have evolved different guises.
The common cuckoo (Cuculus canorus) lays its eggs in the nests of other birds. On hatching, the young cuckoo ejects the host's eggs and chicks from the nest, so the hosts end up raising a cuckoo chick rather than a brood of their own. To fight back, reed warblers (a common host across Europe) have a first line of defence: they attack, or ‘mob’, the female cuckoo, which reduces the chance that their nest is parasitized.
To deter the warbler from attacking, the colouring of the grey cuckoo mimics sparrow hawks, a common predator of reed warblers. However, other females are bright rufous (brownish-red). The presence of alternate colour morphs in the same species is rare in birds, but frequent among the females of parasitic cuckoo species. The new research shows that this is another cuckoo trick: cuckoos combat reed warbler mobbing by coming in different guises.
In the study, the researchers manipulated local frequencies of the more common grey colour cuckoo and the less common (in the United Kingdom) rufous colour cuckoo by placing models of the birds at neighbouring nests. They then recorded how the experience of watching their neighbours mob changed reed warbler responses to both cuckoos and a sparrow hawk at their own nest.
They found that reed warblers increased their mobbing, but only to the cuckoo morph that their neighbours had mobbed. Therefore, as one cuckoo morph increases in frequency, local host populations will become alerted specifically to that morph. This means the alternate morph will be more likely to slip past host defences and lay undetected. This is the first time that ‘social learning’ has been documented in the evolution of mimicry as well as the evolution of different observable characteristics - such as colour - in the same species (called polymorphism).
From the University of Cambridge “When mimicry becomes less effective, evolving to look completely different can be a successful trick. Our research shows that individuals assess disguises not only from personal experience, but also by observing others. However, because their learning is so specific, this social learning then selects for alternative cuckoo disguises and the arms race continues.”.
“It’s well known that cuckoos have evolved various egg types which mimic those of their hosts in order to combat rejection. This research shows that cuckoos have also evolved alternate female morphs to sneak through the hosts' defences. This explains why many species which use mimicry, such as the cuckoo, evolve different guises.”
Physical characteristics
Forests and woodlands, both coniferous and deciduous, second growth, open wooded areas, wooded steppe, scrub, heathland, also meadows, reedbeds. Lowlands and moorlands and hill country to 2 km.
Habitat
Forests and woodlands, both coniferous and deciduous, second growth, open wooded areas, wooded steppe, scrub, heathland, also meadows, reedbeds. Lowlands and moorlands and hill country to 2 km. Food and Feeding
Other details
Cuculus canorus is a widespread summer visitor to Europe, which accounts for less than half of its global breeding range. Its European breeding population is very large (>4,200,000 pairs), and was stable between 1970-1990. Although there were declines in many western populations-most notably France-during 1990-2000, most populations in the east, including key ones in Russia and Romania, were stable, and the species underwent only a slight decline overall
Feeding
Diet based on insects, mainly caterpillars, also dragonflies, mayflies, damselflies, crickets, and cicadas. Sometimes, spiders, snails, rarely fruit. Preys on eggs and nestling of small birds.
Conservation
This species has a large range, with an estimated global Extent of Occurrence of 10,000,000 km². It has a large global population, including an estimated 8,400,000-17,000,000 individuals in Europe (BirdLife International in prep.). Global population trends have not been quantified, but populations appear to be stable so the species is not believed to approach the thresholds for the population decline criterion of the IUCN Red List (i.e. declining more than 30% in ten years or three generations). For these reasons, the species is evaluated as Least Concern.
Breeding
May-Jun in NW Europe, Apr-May in Algeria, Apr-Jul in India and Myanmar. Brood-parasitic, hosts include many insectivorous songbird species, like: flycatchers, chats, warblers, pipits, wagtails and buntigs. Often mobbed by real or potential hosts near their nests. Eggs polymorphic in color and pattern, closely match those of host in color and pattern. Nestling period 17-18 days, evicts host's eggs and chicks.
Migration
Migratory in N of range, arriving in SW Britain mainly Apr - May, when occasionally recorded in small parties, and even in one flock of 50+ birds; also seasonal in hill country from Assam and Chin Hills to Shan States, where present Mar - Aug. Resident in tropical lowland areas of S Asia. Winter resident in sub-Saharan Africa and in Sri Lanka. W Palearctic populations migrate to Africa, where a Dutch-ringed juvenile found in Togo in Oct and a British-ringed juvenile found in Cameroon in Jan; migrants appear in N Senegal as early as late Jul through Oct; in W Africa nearly all records are in autumn ( Sept - Dec), birds apparently continuing on to C & S Africa. Race bangsi occurs on passage in W Africa, and winters S of equator from W Africa to L Tanganyika. Asian populations of nominate canorus and bakeri winter in India, SE Asia and Philippines, also in Africa, but the extent of migration of Asian birds to Africa is unknown; some subtelephonus migrate through Middle East and occur in winter from Uganda and E Zaire to Zimbabwe, Mozambique and Natal. Mainly a passage migrant in Middle East, though some breed in region. Migrants also appear on islands in W Indian Ocean ( Seychelles, Aldabra). Nominate canorus accidental in Iceland, Faeroes, Azores, Madeira, Canary Is and Cape Verde Is, rarely also Alaska and eastern N America; one record of canorus in Indonesia, off W Java in winter. Autumn migration starts in August and continues until October. The main passage through Egypt is in September and the first half of October, with a peak in the third week of September (Goodman & Meininger 1989). Southward movement through Africa lasts from September to December and is linked to the occurrence of rainfall and the growth of cover.
