Cuckoo of the UK and Ireland
The Cuckoo (cuculus canorus) is a popular summer visitor from Africa whose well-known call heralds the beginning of spring. Sadly, fewer people in Britain and Ireland have heard the Cuckoo's much-loved call in recent years.
The decline of the Cuckoo has been well documented by ornithologists and records show their population in Britain has almost halved since the 1980s. The population of Cuckoos has also fallen in Ireland. The British Trust for Ornithology was delighted to announce the Cuckoo had a good breeding season in the summer of 2017/18 with a welcomed increase in their numbers.
Cuckoos are shy and solitary birds who inhabit a wide variety of habitats. They are found in woods (especially birch), wooded farmland, hedgerows on agricultural land, bushy moorland, scrub heaths, marshes, reed beds and large parks.
Irish Cuckoos favour scrub or rough marginal land. The preferred habitat of British Cuckoos is woodland and scrub. Cuckoos are absent from built-up areas such as towns and cities.
Males are often heard singing their familiar "cuc-coo" song perched on tree-tops or telephone wires. The wings droop below the tail when resting on a perch.
Cuckoos arrive in Britain and Ireland in the spring, or between April and May. They leave for their tropical wintering grounds in Africa during the late summer or early autumn, or between June to August.
The southern and central areas of England are home to the greatest proportion of English and Welsh Cuckoos. Scottish Cuckoos are most numerous in western Scotland.
Springalive in Ireland reported Cuckoos were found mostly along the "western seaboard compared to just a handful up the east coast ( Irish Garden Birds).
Immature birds usually follow a month later. Researchers found in 2008 Cuckoos normally return to the areas where they were first hatched (Wiley online library).
The British Trust for Ornithology set up the "Cuckoo Tracking Project" in 2011 to determine the reasons for their decline.
The charity found most Cuckoos arrive in Britain between late-April and May. The majority of these birds leave for their African wintering grounds in the Congo in June.
The folk traditions of Britain said "Farmers used to think it unlucky to hear a cuckoo before breakfast... but a child born on the first day a cuckoo calls in spring would be lucky all its life. The number of ‘cuck-oo’ calls was also said to predict how long you had to live, the number of children you would have, and so on" (Daily Mail).
The Common Cuckoo is classified as of Least Concern by IUCN.
The global population is not considered Vulnerable due to the wide range of their birds (Eurasia and Africa). The global trend is described as decreasing. Europe holds 30% of the global population. The European population was described as having undergone a "moderate decline" of approximately 25% was recorded between 1980 and 2013. (Birdlife International).
The Cuckoo is a red-listed species of bird in Britain. Signs of the deteriorating status of the Cuckoo began in 2002 when it was moved from a green-listed to an amber species of bird and then to the red list in 2015.
The Cuckoo population has been in general decline since the 1980s with a "rapid" fall recorded in England. Wales also saw a significant drop in their numbers, unlike Scotland where the population of Cuckoos has remained relatively stable ( BTO - species).
The Breeding Bird Survey stated the breeding population of Cuckoos in Britain:
- - declined by 50% between 1995 and 2011 (RSPB)
- - declined by 2% between 2012/13 (BTO - page 17)
- - increased by 27% between 2013/14 (BTO - page 13)
- - declined by 1% between 2014/15 (BTO - page 13)
- - declined by 9% between 2015/16 (BTO - page 15)
- - declined by 3% between 2016/17 (BTO - page 15)
- - increased by 22% between 2017/18 (BTO - page 15)
The British Trust for Ornithology was delighted with an increase in Cuckoo numbers during 2017/18 of 22%. The charity said the results provided a welcome break at the end of a long-term decline of 41% (1995–2017) in the UK" (BBS - page 14).
"By 2014 there were only about a quarter of the number of cuckoos being recorded compared to the 1970’s and 1980’s". Records show the greatest declines have been in the south and east of England.
"The Cuckoo is no longer an everyday part of British country life. Indeed if the current rate of decline continues then children growing up today may never hear a cuckoo ( Field Studies).
The declining Cuckoo population has been linked to similar reductions in favoured host species such as Dunnocks and Meadow Pipits. Changes in the dates of egg-laying as host species in Britain are laying their eggs a week earlier due to warmer climate conditions.
A lack of caterpillars as, for example, the Woolly Bear and Garden Tiger moth. Populations of the Garden moth have declined by about 92% since 1968 especially in the south and east of the country.
Cuckoos face a number of dangers when migrating to and from their wintering grounds in Africa. Some of the problems include illegal trapping along the Mediterranean coast and drought in France and Germany in 2015 led to less food available to Cuckoo during stop-overs (Field Studies - please see above link).
The Common Cuckoo was included on the list of birds that are "the most threatened and requiring conservation action under the UK Biodiversity Action Plan (UK BAP)" in 2012 (DEFRA).
The population of Scottish Cuckoos has remained fairly stable and may be connected to the time spent travelling to their wintering grounds in Africa.
"Most cuckoos from lowland Britain migrate south-west in autumn, passing through Spain to Africa. Only about a half make it across the Sahara, probably because they did not find enough food to form fat reserves for the crossing. This would explain why cuckoos in lowland Britain have declined so precipitously.
Scottish cuckoos, by contrast, fly south-easterly in autumn, and fatten up in northern Italy. Ninety per cent of these birds make it safely across the desert. This ties in neatly with the fact that numbers of breeding cuckoos in Scotland are not declining" (Daily Mail).
The Cuckoo is a green-listed species of bird in the Republic of Ireland. Birdwatch reported a decline in the population of the Cuckoo between 1998 and 2010.
Shannon has seen the most significant decline in the population of Irish Cuckoos while a general decline has been reported in eastern areas.
The reasons for the decline of the Cuckoo in Ireland are unknown although loss of habitat due to housing developments and changes agriculture may to blame.
The number of Cuckoos has fallen because of generally declining numbers of migratory birds wintering in Africa and nesting in Europe. Illegal hunting in some Mediterranean countries, which is banned under EU regulations, has also contributed to the Cuckoo's decline ( Western Morning News).
For more information on the Cuckoo of Britain and Ireland, please visit
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