Since 2004, Denmark has systematically monitored the abundance of avian species that form the basis for the designation of the European Union Special Protection Areas (SPAs), under the National Monitoring and Assessment Program for the Aquatic and Terrestrial Environment (NOVANA). The Birds and Habitats Directives require the designation of a network of SPAs as well as Special Areas of Conservation (SACs), where both SPAs and SACs are designated as Natura 2000 areas to protect designated species and habitats (including birds) that require special protection within the European Union. These areas contribute to maintaining biodiversity conservation at national and European levels.
The primary aim of the bird monitoring part of the NOVANA programme is to monitor the distribution, population size and trends of individual species in Denmark. It also provides the numerical basis for comparing the trends in abundance of individual species both within and outside EU Birds Directive Special Protection Areas (SPAs). In this way, the monitoring programme provides the basis for recommending measures to improve the conservation status of the individual species.
This year’s NOVANA bird report presents results from the monitoring conducted during 2024-2025. The species reviews present the status of each species based on the overall monitoring data, while also summarising the results in easily accessible tables and figures. The accounts furthermore include information on short-term and long-term trends in population size and distribution, as well as on the pressures and threats considered to affect bird populations and their distributions. The information is used for Denmark’s reporting under Article 12 of the Birds Directive, and population trends have therefore been assessed in the same way as they are reported to the EU. Consequently, the short-term assessment covers the most recent 12-year period (here 2014-2025), while the long-term assessment covers developments from 1980 onwards (here 1980-2025). However, for many species, data is only available some years after 1980, which is why the start year frequently falls later within the long period.
In 2025, Denmark submitted its third Article 12 report, covering the period 2019-2024. The results are summarized in Fredshavn et al. (2025).
NOVANA includes 49 breeding bird species. For 48 of them, the figures are based on counts in 2024 or 2025, while the figure for white-spotted bluethroat Luscinia svecica cyanecula combines counts from 2023-2026. These breeding species are monitored under two intensive monitoring programmes, Intensive 1 and Intensive 2, while great cormorants Phalacrocorax carbo are monitored under a separate programme. Intensive monitoring seeks to monitor population size and mainly takes place within those SPAs where the species contribute to the designation of the site. For some species, monitoring is nationwide. In the short term, the population size of 23 of the 49 species have increased, six have been stable, five have fluctuated and nine have declined, while six species do not breed regularly in Denmark.
The Intensive 1 programme covers species that occur in, or are known to return to, recognised localities. Of the 37 species monitored under the Intensive 1 programme, 18 species have increased, including black tern Chlidonias niger and Caspian tern Hydroprogne caspia. Nine species have shown stable or fluctuating trends, e.g. ruff Calidris pugnax and spotted crake Porzana porzana, and six species have declined, including Arctic tern Sterna paradisaea and dunlin Calidris alpina schinzii. Four species do not breed regularly in Denmark: golden plover Pluvialis apricaria, little gull Hydrocoloeus minutus, gull-billed tern Gelochelidon nilotica and hen harrier Circus cyaneus. Gull-billed terns have not bred in Denmark since 2016, while a pair of hen harriers bred in Thy in 2025, the first Danish breeding record since 2002.
Examples of featured species:
The Arctic tern is the most widespread tern species in Denmark, typically breeding on small, uninhabited islands and islets with sparse vegetation along the Danish coasts, except on Bornholm. The species is highly migratory, wintering around Antarctica. NOVANA monitoring shows that the Danish breeding population of Arctic terns has declined since monitoring began in 2006. In 2025, 1,906 pairs were recorded in the SPAs, and the national population was most recently estimated at 2,150 pairs in 2023, compared with around 6,000 pairs in 2006.
Dunlin breed in Denmark on wet, short-grazed saltmarshes, formerly also on freshwater meadows inland, migrating via Western Europe to wintering grounds in north-west Africa. This species used to be a common breeding bird on meadows and saltmarshes throughout the country except Bornholm, but during the 20th century it gradually declined as meadows were drained, cultivated and no longer grazed. It now breeds mainly on a few large saltmarsh areas in Western Denmark and at small, isolated sites elsewhere. The population has declined from 242 pairs in 2004 to 58 pairs in 2025.
Black terns breed in colonies by fresh water on open, wet meadows with rushes and sedges, as well as in lakes and marshes with abundant floating vegetation. They winter in West Africa. Black terns formerly bred over most of the country, but the population has declined since at least around 1900, and in 2024-2025 the species bred only in Vejlerne, Husby Sø and Tøndermarsken. In 2025, 88 pairs were registered. The short-term trend is increasing, mainly due to growth in Tøndermarsken, where nest rafts have been provided.
The ruff breeds in Denmark on wet, short-grazed saltmarshes with pans and creeks, as well as locally on freshwater meadows. It winters in West Africa south of the Sahara. As the females alone incubate and raise the young, the population is counted as breeding females. The ruff used to be common in all regions in Denmark except Bornholm, but declined strongly during the 20th century as meadows were drained, cultivated and managed more intensively. In 2024, 68 breeding females were registered in the SPAs, more than double the 28 recorded in 2022 and the highest number since 2012. The short-term trend is fluctuating.
Spotted crakes breed mainly in larger swamp areas and on freshwater meadows with shallow water, typically no more than about 30 cm deep. They winter in Africa south of the Sahara, including East Africa. The species was apparently considerably more common and widespread in the 1800s, but declined significantly through the 1900s due to drainage, cultivation and changed management of meadows and wetlands. Numbers vary strongly from year to year depending on water levels. In 2025, 31 pairs were recorded in the SPAs designated for protecting the species, and the national population was estimated at 116-137 pairs in 2024 and 39-44 pairs in 2025, the lowest number since 2010.
Caspian terns breed on islands and islets along the coasts and forage in lakes and shallow coastal areas. They winter mainly in West Africa. The species recolonised Denmark as a breeding bird in 2008 after being absent for a number of years, and has bred every year since in increasing numbers. All Danish breeding sites are in the south-east of the country. In 2025, 125 pairs were recorded in the SPAs and 131 pairs in the country as a whole.
The Intensive 2 programme covers very rare species, irregularly breeding species and species whose occurrence cannot be predicted. Of these 11 species, five have increasing populations, e.g. golden eagle Aquila chrysaetos and osprey Pandion haliaetus. The peregrine falcon Falco peregrinus shows a fluctuating trend, while three species, Montagu’s harrier Circus pygargus, short-eared owl Asio flammeus and Tengmalm’s owl Aegolius funereus, have declined. The black stork Ciconia nigra has not bred in Denmark since NOVANA began in 2004, and the tawny pipit Anthus campestris has not been recorded breeding since 2017 and is now regarded as an irregular breeder.
Tengmalm’s owls have bred annually in Denmark since 2007, in conifer plantations, today almost exclusively in nest boxes and only exceptionally in old black woodpecker holes. The species occurs in plantations in Jutland, where the birds probably originate from Germany, and on Bornholm, where they probably originate from Sweden. The population peaked at 8-10 pairs in 2023, while three probable pairs were recorded in 2024 and two confirmed or probable pairs in 2025.
Golden eagles breed in old, tall trees in undisturbed forests bordering large open areas such as raised bogs, heaths and meadows. The species re-established itself as a Danish breeding bird in 1997, and the first young fledged in 1999. All Danish pairs breed in Northern Jutland, and the population has increased from three pairs in 2014 to seven pairs in 2025.
Montagu’s harriers breed in Denmark primarily in cultivated fields, especially winter cereals and oilseed rape, and secondarily in treeless heath bogs and marshes with reedbeds. The species requires large open areas around the nest and winters in the Sahel zone of West Africa. It colonised Denmark in the early 1900s and peaked at 350-400 pairs in the 1930s and 1940s. In 2025, 17 pairs were registered, the lowest number since 2010, and the short-term trend is declining.
Short-eared owls breed mainly in large, open, uncultivated areas with low vegetation, such as saltmarshes and river valleys, formerly also more widely in bogs and on heaths. Part of the population winters in Western Europe, including Denmark. The species used to be more common but has declined markedly since the mid-1900s and is now a very rare breeding bird in Denmark. Only one probable pair was recorded nationally in 2024, and three pairs in 2025.
Sixty-eight species of migratory birds were covered within the NOVANA monitoring programme during 2018-2023. Two of these are treated at subspecies level (bean goose Anser fabalis and brent goose Branta bernicla), which explains why a total of 70 taxa are included in the reporting. Among the 70 taxa, divers/loons (4 species) and auks (5 species) are only treated as species groups, as the majority of the observed birds cannot be identified with certainty to species from the air during aerial survey counts.
The majority of the treated species are included as one or more SPA designation criteria, but some other species are included, either because they will be part of the next Birds Directive Article 12 reporting in 2025 for example grey heron Ardea cinerea and purple sandpiper Calidris maritima and/or they are huntable species, e.g. Canada goose Branta canadensis. The Canada goose is also an invasive species that is included in the national reporting to the African Eurasian Waterfowl Agreement.
Of the treated species, 60 species/subspecies are monitored in midwinter, achieved during a nationwide midwinter census in 2020 and 2023. Some of these species are also monitored in other seasons, when they occur in greater numbers (e.g. Bewick’s swans Cygnus columbianus in spring and autumn, dabbling ducks in autumn), yet other species are primarily monitored in other seasons, especially waders, because with a few notable exceptions, most shorebirds overwinter outside the country. Newly included species in this report include the northern fulmar Fulmaris glacialis, Kentish plover Charadrius alexandrinus, spotted redshank Tringa erythropus, spoonbill Platalea leucorodia and Sandwich tern Thalasseus sandvicensis, species that were only first included as migratory staging birds as the specific designation criteria for SPAs in 2022.
The majority of the treated species have stable or fluctuating numbers (e.g. Bewick’s swan, goldeneye Bucephala clangula and goosander Mergus merganser) or are increasing (e.g. whooper swan Cygnus cygnus, almost all species of geese, several species of dabbling ducks) both in the shorter term (typically over the last 10-12 years) or longer period of time (back to the late 1960s or early 1980s – depending on the species group).For some species, we are able to provide data back to the very first nationwide censuses from 1967-1973. In the case of the smew Mergellus albellus numbers have increased over a prolonged period, but in recent years numbers have been stable or fluctuating. For several marine species, trends in abundance over longer periods are difficult to assess due to gradual changes in count methods that were implemented in the 2000s. For several of the more maritime species, changes in abundance have been difficult to assess due to gradual changes in methodology implemented in the 2000s. Some species have shown declining trends (both over short and longer periods), for example, common eider Somateria mollissima, the scaup Aythya marila which has been in decline over a long period, while other species seem to have been in decline over the shorter time period, e.g. Bewick’s swan, taiga bean goose, pochard Aythya ferina and common scoter Melanitta nigra. Many of the wintering waterbird species fluctuate in numbers depending on the severity of the winter, with low numbers in cold winters and greater abundance in mild winters. For example, this is the case for Bewick’s swan and coot Fulica atra, although the latter is now increasing in the short term after major declines between 2000 and 2016 despite relatively mild weather in the majority of winters over that period. Apart from mallard, the number of dabbling ducks in winter is also strongly dependent on the weather, and the increasingly frequency of milder winters has resulted in more and more dabbling ducks wintering in Denmark, this is especially the case for Eurasian wigeon Mareca penelope, gadwall Anas strepera, Eurasian teal A. crecca and northern pintail A. acuta, but also for northern shoveler Spatula clypeata. Eurasian wigeon became the most numerous dabbling duck species in Denmark in 2020 and 2023, in all other 15 midwinter counts, the species has been outnumbered by the mallard based on nationwide counts from 1968-2016. Most of the waders have shown fluctuating numbers, making the assessment of population trends difficult, but Eurasian oystercatchers Haematopus ostralegus and red knot Calidris canutus seem to show declining trends.
The report presents modelled estimates of national numbers of divers/loons, selected diving ducks (common eider Somateria mollissima, common scoter, velvet scoter Melanitta fusca, long-tailed duck Clangula hyemalis and red-breasted merganser Mergus serrator) and auks. These are all species that are counted in particularly large numbers in marine areas which are covered by transect counts from aircraft. In the case of the divers and most sea ducks, the new estimates show levels of abundance comparable with those from 2004 and 2008, although the common eider appears to be in decline while numbers of auks seem to be fluctuating without trend. Numbers of common scoter have been stable in the short term, but modelled estimates suggest that there were more birds in the inner Danish waters in the 2000s compared to today.
We introduced a new map design for 2020 and 2021 data presentation in the previous 2020-2021 NOVANA report, which we continue here. The maps provide an immediate visual impression of where the largest numbers of a given species occur in the country, including the number counted in individual SPAs. A table provided under each map also provides statistics on the proportion of the population that has been counted in SPAs and in the Natura 2000 area network as a whole. These statistics can be used directly to support the next round of Article 12 reporting. A full explanation of the maps and their derivation can be found in the section on “Explanation of the maps”. However, for the marine species whose numbers have been calculated using modelling, we have yet to calculate the proportions within the SPAs.
An additional eight species (great northern diver Gavia immer, Slavonian grebe Podiceps auritus, red-crested pochard Netta rufina, merlin Falco columbarius, lapwing Vanellus vanellus, jack snipe Lymnocryptes minimus, Iceland gull Larus glaucoides and glaucous gull Larus hyperboreus) are treated briefly in the report under the group "Other species". These species are all scarce wintering species to be included in the next Article 12 reporting. Two new species included in report due to the obligation to report under Article 12 are the grey heron and great white egret Ardea alba.
For the sake of completeness, the report also mentions 5 species of birds of prey (white-tailed sea eagle Haliaeetus albicilla, hen harrier, golden eagle Aquila chrysaetos, osprey Pandion haliaetus and peregrine falcon), Kentish plover, little gull Hydrocoloeus minutus and short-eared owl, which contribute to the designation criteria applied to SPAs in 2018-2023. These species are not discussed in detail here in the report, but will treated in more detail in an upcoming report that discusses migratory bird populations in Danish SPAs up to 2023. This will update the report Migratory bird populations in the Danish special Protection Areas 2004-2017 (Clausen et al. 2019).
