Newly published research has revealed worrying declines among several ground-nesting bird species in southern Iceland.
Iceland has a relatively low human population compared to the rest of Europe, while grazing has left the landscapes open and dominated by short vegetation for centuries. This has made Iceland an ideal nesting area for open-habitat specialists and it currently holds several internationally important shorebird populations.
It is estimated that approximately 1.5 million pairs of waders breed in Iceland in the summer and consequently an estimated 4-5 million breeding adult and juvenile waders migrate from the country each autumn. This makes Iceland a major population source for the East Atlantic Flyway, and any substantial changes to the large Icelandic wader populations are likely to impact the non-breeding populations of many countries across Western Europe and West Africa.
Black-tailed Godwit was one of seven wader species monitored in the study (Carl Corbidge).
Southern Icelandic study
The research focused on Iceland's Southern Lowlands. Once an open landscape lacking human presence, this region is witnessing rapid land-use change through the construction of houses, roads and power lines, and the expansion of plantation forests and agricultural areas.
Given that ground-nesting birds tend to be sensitive to such changes, Aldís Pálsdóttir and her colleagues decided to investigate population trends between 2012 and 2024 in nine species to see if there had been any impact. These comprised two passerines (Meadow Pipit and Redwing) and seven waders (Common Snipe, European Golden Plover, Eurasian Oystercatcher, Whimbrel, Black-tailed Godwit, Common Redshank and Dunlin).
Fieldwork was conducted along road transects, while land-use information was gleaned from satellite imagery. The latter was then compared with bird densities to further understand any relationships.
European Golden Plover is declining in Iceland's Southern Lowlands (Robin Gossage).
Negative trends
Alarmingly, only one of the nine species – Redwing – was found to have increased over the 12-year study period. Meadow Pipit, the other passerine studied, showed a gradual decline of 2% per year.
The picture was somewhat bleak among the waders studied. Six of the seven species were shown to be in decline, some of them considerably so.
The most rapid decrease was found in Dunlin, which had dropped by 10% each year. The authors offered the caveat that this may be an overestimate due to unusually high numbers recorded in the initial survey year of 2012. However, even by discounting this anomalously good season, the species is still declining at approximately 8% per year.
Whimbrel was found to be decreasing by 5% per year. Given that Iceland supports approximately three-quarters of the European breeding population, the observed decline has a continent-wide significance.
A similar rate of decrease was noted in Black-tailed Godwit in the Southern Lowlands. However, writing on the Wader Tales blog, shorebird expert Graham Appleton pointed out that WeBS counts of Black-tailed Godwit in the UK for the period 2012-2023 gives no indication of a decline, adding that this species has expanded into northern and eastern areas of Iceland, and it could be that increases there are offsetting declines in southern Iceland.
European Golden Plover, Eurasian Oystercatcher and Common Redshank were all found to have declined by approximatel 6% per year during the study period.
Common Snipe was the only shorebird not to have declined, with no trend detected – this species is seemingly able to adapt to early-stage forestry and will also contentedly breed around residences.
Of the seven wader species studied, Common Snipe was the only one not to show a decline between 2012 and 2024 (Dave Jackson).
Cause for concern
The researchers described the results of their study as "a grave cause for concern", adding that "human influence on terrestrial bird habitats is increasing greatly".
The team was not able to identify a single environmental factor as the driver behind the observed changes, adding that they are likely driven by a "combination of factors combined with the life-history traits of individual species."
What was clear, however, is that steep declines have been identified in a region that is under increasingly high anthropogenic pressure compared to the rest of Iceland.
The team wrote: "It is therefore imperative that Iceland adopts an early intervention strategy to fulfil international commitments for species and biodiversity conservation. Designating large areas of Iceland for the conservation of waders and open-habitat species, which is organised and integrated into land-use, seems essential.
"Additionally, further research to understand the drivers of the declines observed in this study is essential to inform conservation action and site protection policy."
Reference
Pálsdóttir, A E, Þórisson, B, and Gunnarsson, T G. Recent population changes of common waders and passerines in Iceland's largest lowland region. Bird Study. DOI: https://doi.org/10.1080/00063657.2025.2450394
