Successes for seabirds in Ireland in new census results

Date Released: Thursday, November 16, 2023

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 25 regularly breeding species of Britain, Ireland, Isle of Man and the Channel Islands.

  • Latest survey reveals over three quarters of seabird species breeding in Ireland have increased, with two species declining.
  • Census shows that Ireland is particularly important for species such as Roseate Tern and European Storm-petrel as 94% and 73% of the total populations breed here.
  • Roseate Tern, European Storm-petrel and Razorbill are some of the 17 species which have increased over the last twenty years. Species in decline are Kittiwake and Puffin.
  • Increasing populations of some seabird species are linked to effective conservation management measures, such as tern-wardening projects.

Over three quarters of seabird species that breed in Ireland have increased over the past twenty years, according to a census published today, November 16th.

Seabirds Count – the Census findings

The survey took place between 2015 and 2021 and was led by the Joint Nature Conservation Committee (UK) with over 20 steering group partners (see Editor’s Notes).

In Ireland, the key partners who spearheaded efforts to collect and publish the findings are BirdWatch Ireland and the National Parks and Wildlife Service.

Seabirds are doing well in Ireland with 17 species increasing and only two declining. A similar pattern prevails in Northern Ireland, with four species declining and nine increasing. This is in contrast to census results across the entire UK and Ireland, which show that 11 of the 21 seabird species, where there is confidence in their trends, have declined since the last census in 1998-2002. The results differ significantly by region or country. There are encouraging trends in Ireland for species such as the Black-headed Gull and the Arctic Tern. At the overall census level, the Arctic Tern breeding population is in decline (35%), however the population is considered stable across the island of Ireland.

The Black-headed Gull, which breeds on inland wetlands as well as the coast has suffered an overall decline of 26% but  this is in contrast with an analysis of Irish data which shows increases (Ireland 84%; NI 23%, all-island 40%).

Overall, Black-legged Kittiwake has declined by 42% since the last census, but the population in Northern Ireland bucks this trend and shows an increase of 33%. Further south in Ireland the population is in decline (36%). Little appears to have changed in the colonies where they breed, so these declines are driven by changes in the marine ecosystem upon which they depend.

Other main drivers for declining populations vary between species and even location, however there are some prevalent themes. Predation is a common problem: eggs, chicks and adults can be eaten by native and invasive predators, such as American Mink, which may have been released onto or swum to seabird colony islands and in the case of Brown Rats, may have stowed away on boats.

Climate change is another important factor. Adverse weather conditions are causing nest sites to be swept away and making foraging conditions more difficult. Increased water temperatures reduce the availability of important food such as small fish, e.g. sandeels and sprats, which leads to seabird parents not finding enough food. This could be exacerbated by fish stock depletion by commercial fisheries, meaning that there is not enough food to go around during the important breeding season.

Minister for Nature, Heritage and Electoral Reform, Malcolm Noonan TD said:

Seabirds Count is a hugely impressive body of work on the status of all the breeding seabird populations that we find on our coastlines, north and south. It is encouraging to see evidence that investing in conservation efforts can and does reap dividends, notably for the Roesate Tern. And while some of the findings are worrying, not least for the iconic Puffin and Kittiwake, this book provides some really valuable insights into how we can better protect them now and into the future. This publication is a real achievement for partners, including the NPWS, BirdWatch Ireland and RSPB who have been working together to collate and analyse the data in Ireland. We are privileged to share this island with so many species of seabirds and it is incumbent on all of us to do everything we can to protect them and the habitats they depend on.”

Linda Lennon, CEO of BirdWatch Ireland, said:

“Seabirds Count is an incredible piece of work, the product of many thousands of hours of work by hundreds of volunteers, culminating in this beautifully presented book.

“It is heartening to see how well Irish terns are doing, in particular, and this really stresses the importance of our work with NPWS at key east coast colonies such as Rockabill, Kilcoole and Lady’s Island Lake. However, focus must also be shifted towards the west of Ireland and similar management measures implemented there too.

“The survey work has revealed some concerns. The Puffin is such an iconic species, and the news of a significant decline in Ireland is very worrying. BirdWatch Ireland will be prioritising better monitoring and research on Puffins in the coming years to improve our understanding of their ecology and demography and to inform policy change to improve the status of the vital North Atlantic Ocean ecosystem which supports them.”

Niall Ó Donnchú, Director General of the NPWS said:

“NPWS is committed to delivering on our mission to protect nature on the basis of robust evidence. The Seabirds Count is a great example of how organisations can pool resources to monitor our diverse seabird population on the island of Ireland and provide us with comprehensive, quality data to inform our conservation management and responses. It is encouraging to see strong increases in some populations such as the Roseate Tern, recorded at sites where targeted management measures such as wardening projects have been put to use during summer months.”

International importance of our seabird populations

Britain and Ireland together hold most of the world’s nesting Manx Shearwaters, Northern Gannets and Great Skuas. These islands also hold more than half of the North Atlantic breeding population of two further species: Lesser Black-backed Gull and Common Guillemot. In addition to these, five species have over 30% of their North Atlantic population breeding in Britain and Ireland: European Storm-petrel, European Shag, Herring Gull, Roseate Tern and Razorbill.

Across Britain and Ireland, the census shows that Ireland is particularly important for species such as Roseate Tern and European Storm-petrel as 94% and 73% of the total populations breed here.

The census noted increases in the following species of seabirds breeding in Ireland and Northern Ireland. 

Roseate Tern

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.

European Storm-petrel

It is estimated that circa 38% of the entire global population of European Storm-petrel breeds in Ireland. The majority of the Irish birds breeds in large colonies located off the southwest coast. Numbers from the census appear to show a stable population. European Storm-petrels are hard to count, being small, nocturnal and nesting underground, and thus require the use of new technology and innovative approaches.

Black-legged Kittiwake

The Black-legged Kittiwake is a seabird species in decline globally, which appears to follow a similar trend in Ireland. Numbers in the census show an overall decline of 42%, the lowest recorded in any census to date. The Kittiwake is known for its loud, noisy, trisyllabic call, from which its English name is derived. It forms colonies, often with other seabirds, and breeds on steep sea cliffs. The main reasons for its decline appear to be the reduction of sandeel availability due to climate change, local predation and extreme weather events.


The Razorbill is found in both Ireland and Northern Ireland. They nest on boulder beaches and on ledges and crevices on sea cliffs. Since the last census, the Razorbill has increased in Ireland by 19% and in Northern Ireland by 3%. The designation of Protected Areas (SPAs) has been important in supporting the Razorbill population. Their diet includes small fish (sprat and herring). They are vulnerable to climate change and extreme weather events.

Background on Seabirds Count is available on the Joint Nature Conservation Committee website.