Arctic Tern
| Irish Name: | Geabhróg artach |
| Scientific name: | Sterna paradisaea |
| Bird Family: | Terns |
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Conservation status
Conservation status
Status
Summer visitor from March to September to all Irish coasts. Winters off south Africa and as far south as Antarctica.
Identification
Usually seen over the sea. Slender seabird with narrow, pointed wings, long forked tail and long, pointed bill. Grey above and white below, dark cap to head. Flight light and buoyant, can hover briefly over the sea before diving in. Very similar to Common Tern (with which it breeds) and told apart by plumage and structure. Arctic tern is smaller, with a smaller head, neck and bill and slightly narrower wings, which look forwardly placed on the body. Very short legs. Adults have a blood red bill, usually with no dark tip. The underparts are greyer than Common Tern and there some contrast with the cheek. The wing pattern is useful in separation, Arctic terns shows no dark wedge in the primaries but shows a distinct trailing edge. Arctic terns have longer tail steamers, extending beyond the wing tips. Adult winter plumage, like all terns is different from breeding plumage, but is only seen in the wintering range. Also has distinctive juvenile plumage, with some brown in the mantle, a dark carpel bar and white secondaries. Shows a distinct trailing bar to the primaries, bill darkens rapidly.
Voice
Similar to Common Tern.
Diet
Marine fish, crustaceans and insects.
Breeding
Mainly a coastal breeding bird, but in Ireland the species also breeds inland on the fresh water lakes of Lough Corrib (Co. Galway) and Lough Conn (Co. Mayo). More colonies are found on the west coast with Co. Wexford, Co. Kerry, Co. Mayo and Co. Donegal having the largest number of birds
Wintering
Considered to have the longest migration of all birds, utilizing the summer of both hemispheres.
Monitored by
All-Ireland tern survey in 1995, and through breeding seabird surveys carried out every 15-20 years. Arctic Terns are also monitored annually at Rockabill and Lady’s Island Lake.
Lady’s Island Lake, near Rosslare, in County Wexford has up to 300 pairs. As well as other tern species.
Lady’s Island Lake, near Rosslare, in County Wexford has up to 300 pairs. As well as other tern species.
Blog posts about this bird
Seabird Census shines light on plight of seabird populations in Ireland and Britain
A newly-published seabird census highlights how conservation management measures can boost tern populations, while also revealing concerning declines in Puffin and Kittiwake populations in Ireland.
Seabirds Count, released as a book by wildlife publishers Lynx Edicions, is the most comprehensive seabird census produced to date, providing population estimates for the regularly breeding species of Britain, Ireland, Isle of Man and the Channel Islands.
The census, which ran from 2015 to 2021, covered all of our regularly breeding seabird species, including nocturnal burrow-nesters such as Manx Shearwater, inland and urban-nesting gulls and several rare species. Led by the Joint Nature Conservation Committee (UK) with over 20 steering group partners, including BirdWatch Ireland and the National Parks and Wildlife Service, who spearheaded efforts to collect and publish the findings in Ireland.
The census results underscore the benefits of focused conservation management work, while also revealing some concerns. Results differ significantly by region or country. However, overall results show that, across the entire UK and Ireland, 11 of the 21 seabird species with comparable data have declined since the last census in 1998-2002.
In Ireland, 17 species have seen population increases, while two – Puffin and Black-legged Kittiwake – have experienced declines.
Puffin. Photo: Brian Burke
Puffins are reliant on sandeels and this crucial food source is in decline in waters off Britain and probably Ireland. This is one of the many potential factors contributing to the species' decline, though more research is needed to get a full picture of what is affecting this iconic bird. The Puffin has declined by 28% in Ireland and is now a Red-listed bird of conservation concern, meaning it is vulnerable to extinction. The Black-legged Kittiwake has declined by 36% in Ireland since the previous census. While Northern Ireland has seen a 33% increase in this species, overall, the species is on the decline. Numbers in the census show an overall decline of 42%, the lowest recorded in any census to date. The main reasons for its decline appear to be the reduction of sandeel availability due to climate change, local predation and extreme weather events. There are encouraging trends in Ireland for species such as terns. This underscores the importance of our tern wardening work with NPWS at key east coast colonies such as Rockabill, Kilcoole and Lady’s Island Lake. However, while the Arctic Tern population is stable in Ireland, at the overall census level, there has been a 35% decline in the Arctic Tern breeding population since the previous survey. Across Britain and Ireland, the census shows that Ireland is particularly important for species such as Roseate Tern as 94% of the total populations breed here.
Roseate Tern. Photo: Brian Burke.
The Roseate Tern populations at Rockabill and Lady’s Island Lake have benefitted from a range of conservation efforts via ongoing NPWS wardening projects, delivered by BirdWatch Ireland. Driven to the brink of extinction due to the use of their feathers for the hat trade during the 19th century, the Roseate Tern population recovered through protective legislation and management. Rockabill holds the vast majority of the northwest European breeding population and, thanks to the ongoing conservation management, numbers have increased by 155% since the last census. However, the Roseate Tern remains one of our rarest seabirds, with an estimated 2,000 pairs confined to a few colonies around these islands, and in 2023 both the Rockabill and Lady’s Island Lake tern colonies were impacted by a Highly Pathogenic Avian Influenza (HPAI) outbreak. An increase in testing, the quicker removal of carcasses after they have been reported and more collaborative action and joined-up thinking between all relevant stakeholders are required if we wish to stem potential devastating effects of avian flu on seabird populations. Ireland is also of importance for European Storm-petrels, with 73% of the census population breeding here. The majority of the European Storm Petrels in Ireland breed in large colonies located off the southwest coast. Numbers from the census appear to show a stable population. Meanwhile, the Black-headed Gull has seen an increase of 84% in Ireland, which is in contrast with overall census-level decline of 26%. While there are certainly reasons for hope, it is clear, to halt and reverse the overall decline in our seabird populations, much more needs to be done to protect these birds and their breeding and foraging areas from the multitude of threats they face.
Bird ‘Flu Devastates Key Irish Seabird Colonies
BirdWatch Ireland staff have been dealing with alarming and unprecedented outbreaks of the highly pathogenic H5N1 strain of avian influenza, or bird ‘flu, at some of Ireland’s most important seabird colonies. Over the past few weeks, the carcasses of hundreds of dead seabirds, both adults and chicks, have been recovered for disposal, in an effort to try to prevent further spread of this highly contagious viral disease. There are fears for the long-term devastating consequences this outbreak may have on Ireland’s seabird populations, which are of international importance.
During the current nesting season, the hardest hit birds have been members of the tern family, a group of migratory seabirds which visit Ireland each summer to breed. All five of Ireland’s breeding tern species are ‘Amber-listed’ species of conservation concern, meaning that their populations were already been identified as being at risk before the current disease outbreak.
Please click here to donate to our Bird 'Flu Emergency Appeal
Last summer, seabird colonies across Ireland, Britain, Europe and other parts of the world were severely impacted by the same H5N1 strain of bird ‘flu, in what was the worst global outbreak of this disease in history. Populations of the Gannet, Ireland’s largest breeding seabird species, were particularly hard-hit: please click here for more details. Elsewhere in Europe, large numbers of terns perished at their nesting colonies. Our Irish tern colonies were not impacted last summer, but unfortunately it seems that their luck has run out this year. BirdWatch Ireland manages the four most important tern colonies in Ireland. Monitoring and conservation at Lady’s Island Lake (Wexford), Rockabill Island (Dublin) and Kilcoole Beach (Wicklow) is in conjunction with, and funded by, the National Parks and Wildlife Service, and our work on the Dublin Port Tern colony is funded by Dublin Port Company. Although it is still too early to assess the full impacts on populations, at the time of writing more than 160 adult Common Terns, along with over 450 Common Tern chicks, have been found dead at the breeding colony at Lady’s Island Lake, with the disease now also threatening the populations of Sandwich Terns and Roseate Terns that also nest there. The disease has probably spread from the earlier-nesting Black-headed Gulls also present at the same location, which hosts the species’ largest colony in Ireland.
Dead terns at Lady's Island Lake, Co. Wexford: victims of bird 'flu (Photo: BirdWatch Ireland)
Lady’s Island Lake and Rockabill Island are home to the two largest mixed-species tern colonies in Ireland, with the latter holding 1,750 pairs of Roseate Terns. This means that it is, by far, the largest and most important breeding colony for this threatened species in all of Europe, holding approx. 60% of the European population. A large-scale outbreak of bird ‘flu in this colony would have disastrous repercussions for Roseate Terns at an international level. Since 1st July, a small number of adult Common Terns have been found dead or dying on Rockabill Island. Unfortunately, the carcasses sent to the Department of Agriculture, Food and the Marine for analysis have tested positive for bird ‘flu.
BirdWatch Ireland fieldworker wearing PPE, collecting bird 'flu victims (Photo: BirdWatch Ireland)
These outbreaks are very worrying for the future conservation of our tern species. A poor breeding season at a tern colony, with few chicks surviving, is unfortunate, but can be compensated for by better breeding success in subsequent years. However, the deaths of large numbers of adult terns of breeding age has a much bigger impact, and recovery will take a long time. BirdWatch Ireland will continue to monitor these outbreaks and remove carcasses, wherever it possible to do so safely. Experience from seabird colonies elsewhere in Europe last summer has shown that carcass removal is a key action to minimising the spread of avian influenza.*********************************
All of us at BirdWatch Ireland would like to extend our heartfelt thanks and appreciation to everyone who has donated to our Bird ‘Flu Emergency Appeal to date. The funds raised have been an enormous help in covering the cost of specialist personal protective equipment and training for our tern colony wardens. When faced with a crisis such as this one, we depend heavily on the generosity of our members and supporters, and your support has been vital in minimising the impacts of this terrible disease and keeping our wardens safe. If you wish to donate to BirdWatch Ireland's Bird ‘Flu Emergency Appeal, please click here.*********************************
We would like to remind the public not to touch any sick or dead seabirds, but to report them via BirdTrack and the Department of Agriculture’s ‘Avian Check’ web page.
If you own chickens or other poultry then please consult the Department of Agriculture website for further advice.
