By Mary Colwell and Russell Wynn
- Finland has a human population of 5.5 million, the UK is nearly 70 million. Finland in 1.4 times larger than the UK. Most people live in the south of Finland.
- More than 75% of Finland’s land area is forested, but these forests are significantly different to UK woodlands, therefore comparisons between them are limited.
- The Finnish Curlew population is similar in size to the UK, between 45-60,000 pairs, and 90% of them nest on farmland found in southern and central regions. Curlews do breed on the peatland and forest mires (mainly in central and more northerly regions), but they are thinly spread. These are marginal habitats due to the long, cold winters and wet ground.
- Curlew appears stable in some areas, especially on peatland, but are declining rapidly in southern, farmed regions.
- Meso-predators such as Fox, Badger and corvids exist at lower densities in Finland than in the UK due to a combination of lower food availability, particularly through the winter, and targeted predator control to protect shooting interests.
- Apex predators are unevenly distributed and also subject to control for hunting management.
- Our findings suggest that breeding Curlews can persist close to trees if meso-predator densities are kept sufficiently low to allow them to be productive, which is not the case in most farmland habitats in the UK.
Curlew Action visited Finland in May 2023 to better understand the relationship between Curlew (and by extension other ground-nesting birds), forests, and predators, and to generate evidence that will help inform curlew conservation efforts in the UK.
Forestry is expanding rapidly in the UK, with a target of planting 30,000 hectares of woodland (between 90-120 million trees) each year by March 2025. Based on recent trends, future planting will mostly be focussed on higher, open ground, particularly the so-called unproductive farmland often used for rough grazing, which is where a large proportion of our curlews and other waders breed. There is concern about direct loss of breeding habitat, but also that new plantations will increase the predation threat to the eggs and chicks of ground-nesting birds, with species such as Fox readily establishing dens in woodland. As waders are already suffering severe declines in the UK, we wanted to know more about these relationships.
Why Finland? An increasing narrative is that Curlews and woodlands can coexist under the right conditions, as they do in Finland, where Curlew populations are apparently stable in many areas. Finland has a lot of trees and a lot of Curlews, with the current curlew breeding population estimated at 45,000-60,000 pairs (similar to the UK), so what is the story?
To find out more we visited North Karelia, an eastern province of Finland that borders Russia, between 14 and 17 May 2023. Tero Mustonen, the Founder and President of the eNGO Snowchange, kindly organised a packed two-day itinerary in this area that allowed us to see different breeding habitats of curlews and other waders, including areas of peatlands that form part of the Snowchange Landscape Rewilding Programme.
A series of illustrated daily blogs providing further details of our activities can be viewed here.
Location of North Karelia in Finland
Visited sites near Joensuu and Ilomantsi
Variaty of landscpaes visited
Linnunsuo wetland (Snowchange website)
North Karelian Farmland
Curlew in Kesonsuo peatland
The Finnish landscape
While traveling to and through North Karelia the most obvious landscape difference to the UK was the abundance of forest. More than 75% of Finland’s land area is forested, comprising nearly 23 million hectares; consequently, it is the most forested country in Europe and the percentage of forest cover has increased in recent decades. While driving between sites, the dominantly flat terrain and flanking forests ensured that expansive views were limited.
About 13% of the forests are protected (only 5% is old-growth), equating to nearly three million hectares, most of which is fully excluded from felling. The dominant tree species are spruce, pine, and birch, both in old-growth forests and commercial forests, so plantations are wholly comprised of native species, unlike in the UK where non-native species such as Sitka spruce dominate.
Aside from the abundant lakes, the other major components of the Finnish landscape are peatlands and farmland. Peatlands originally covered about one-third of the land area; however, over half of these have been drained for farming, forestry, and peat extraction. There are two million kilometres of ditches in Finland, making it one of the most ‘ditched’ countries in the world. Spectacular peatland sites like the one we visited at Kesonsuo are remnants of what was once a far more extensive peatland habitat.
Peatlands near Ilomantsi - adjacent forests are mostly commercial plantations.
Farmland comprises about 7.5% of Finland’s land area, i.e. an order of magnitude less than the forested area. Most of this farmland is used for grass crop production and arable crops. The number of farms has shrunk since the 1960s and the average size has risen to around 50 hectares, with larger farms in the south (the average UK farm is 81 hectares, but half of all farms are less than 20 hectares). Finnish agriculture is incorporated into the Common Agricultural Policy of the European Union.
Farmland near Liperi with numerous breeding curlew and lapwing + flocks of barnacle geese on migration stop-overs.
In summary, three-quarters of the land area of Finland is forested and the forests are predominantly formed of native species. In contrast, the UK is three-quarter farmland with forests covering just 13%. Half of this is native trees species, the other in non-native plantation. (https://www.woodlandtrust.org.uk/state-of-uk-woods-and-trees/)
Meso-predators in the Finnish landscape
Another obvious difference that we noted during our travels was the relative lack of meso-predators - for example, the absence of large numbers of raptors, corvids, and large gulls in the farmland areas was particularly striking compared to equivalent habitats in the UK.
We were also surprised at the lack of roadkill of nocturnal mammals such as Fox, Badger and non-native Racoon Dog. This could be attributed to low traffic density, but we were told that in more northerly regions it is also a function of the long, hard winters and the lack of easily obtainable food. Snow can lay on the ground for six months of the year and temperatures can dip to -20-30oC, especially away from the far south. The so-called hungry gap in late winter will therefore significantly thin out populations of both predators and prey. In southern Finland the climate is not such a big factor in population density.
Meso-predators are also subject to hunting pressure across the country and government figures of bag numbers can be seen here. For example, in 2021 across the whole of Finland, bag numbers were: 40,000 Red Fox, 114,600 Racoon Dog, 10,500 Badger, 104,300 Hooded Crow. However, hunting pressure varies from region to region depending on local conditions and issues. The non-native Racoon Dog is especially targeted.
Hooded crow in curlew breeding habitat on the Syvaysjoki River; hooded crows and ravens were the only avian meso-predators that we observed at the curlew breeding sites we visited, and we only ever saw a few individuals.
Therefore, densities of meso-predators vary across the country, for example, North Karelia has 10 times more Racoon Dogs than further south (pers comm Mikko Alhainen, Finnish Wildlife Agency), and Red Fox is in high densities across southern Finland, especially around urban centres. See here for more details.
Apex Predators in Finland
It is frequently suggested that the re-introduction of apex predators into the UK, including Wolf, Lynx, and eagles, will significantly reduce the high numbers of meso-predators. Finland’s apex predators include Brown Bear, Wolf, Wolverine, Lynx, and various eagles and large owls. Our discussions with local scientists suggest the relationships between meso and apex predators are complex and vary from region to region. They are also affected by local climate, human population density, reindeer herding, habitat loss and/or degradation, and hunting pressure. For example, Lynx are more common away from reindeer herding areas, Brown Bear is widespread but with lower densities around human populations, and wolves are found around lakes. As hunting is a popular pastime in Finland, many forests are managed for game such as various grouse species and Moose. For example, 140,300 Black Grouse and 27,900 Capercaillie were shot in 2021. Predators that impact on these quarry species, or which threaten hunting dogs, e.g. Brown Bear and Wolf, are suppressed. Figures for 2021 show the predator bag numbers were: 354 Lynx, 35 Wolf, 389 Brown Bear. More info about the distribution of large carnivores can be found here.
From pers comm with Mikko Alhainen, wolverine can affect Racoon Dog distribution, and Lynx affects the presence of Red Fox, but any natural interaction is tempered by control of apex predators through hunting derogations.
Interactions between breeding curlews, trees, and predators in Finland
These differences are important when we consider the relationship between breeding curlews, trees, and predators. Curlews do nest relatively close to trees in North Karelia - not in the middle of forests, but in isolated peatlands and pockets of farmland surrounded by trees.
The peatlands are too wet for most trees and host a wide variety of wetland ground-nesting bird species, primarily wildfowl and waders. During and immediately after the spring snow melt, the ground is too saturated and exposed for mammalian predators like foxes to range efficiently. There are also many eyes and ears to raise the alarm if any predators are seen, making it a relatively safe environment for breeding curlews. Perhaps surprisingly, the density of breeding curlews is not that high in these peatland habitats (previous surveys at Kesonsuo peatlands suggest a couple of pairs per km2) but the populations have persisted for many decades and breeding success is likely higher than in farmland areas leading to relatively stable populations.
It is estimated that 90% of breeding Curlews in Finland occur on farmland, where trees have been cleared for agriculture. Breeding densities of Curlew appear to be higher in these farmed habitats than on peatlands, e.g. recent records of 5-17 pairs per km2 in the southern parts of North Karelia (unpublished data, ref: Tuomas Seimola, Institute of Natural Resources, Finland). However, they are likely to be less productive, with a 60% nest failure rate and roughly two-thirds of failures attributed to nocturnal predation (primarily Fox and the non-native Racoon Dog); the remaining one-third of failures are attributed to farming operations and other causes - these figures and drivers are not unfamiliar to Curlew fieldworkers operating in farmland habitats in the UK.
An interesting additional pressure on farmland Curlews in the areas we visited is the rapidly increasing Barnacle Goose population that numbers over 1.4 million birds; a large proportion of these birds pass through Finland on migration and utilise farmland for feeding stopovers, where flocks of several thousand can occur on a single large field - these concentrations of feeding geese can significantly reduce sward length, leaving any nesting Curlews exposed to increased predation risk.
Our short visit to Finland confounded expectations and was surprising and challenging. Based on the published studies and information we gathered we conclude that curlews can only persist in close proximity to trees when meso-predator densities are sufficiently low for breeding pairs to be productive. This seems to be the case in parts of Finland, especially in the wetter and more extensive peatlands, but it is not the case in farmed landscapes in the UK where we have some of the highest meso-predator densities in Europe.
Several studies have documented how forests harbouring meso-predators negatively impact curlew productivity in adjacent open habitats. The resources required to effectively mitigate the increased predation threat in these situations are not insignificant, for example, a 2013 paper led by David Douglas of the RSPB showed that increasing woodland cover from 0% to 10% of the land area within 1 km of curlew breeding sites requires a near 50% increase in human predator control effort to achieve curlew population stability; these indirect ‘edge effects’ are of course additional to direct habitat loss due to planting on open ground.
A further consideration that was much discussed during our visit is the degree to which local and national communities are connected to nature, and the influence this can have on understanding and implementing policy measures pertinent to curlew conservation. We heard from our colleagues in North Karelia that the arrival of the curlew in spring continues to be a welcome sound for farmers, while also providing a timely warning call that the ice is no longer safe to cross. In addition, we were told of the importance to young and old of foraging for berries and fungi in the forest, and of the large proportion of the population that fish and hunt game. Even the toilets at Helsinki Airport were enhanced by a loop recording of singing willow warblers, and images of forest scenes brightened up the internal walls of the toilet on our cross-country train. This ongoing connection to nature, especially in more remote areas, facilitates bottom-up conservation initiatives that are driven by local communities seeking to deliver local solutions using local knowledge, which is different to the conventional top-down model where national- or regional-scale initiatives are driven by government agencies and major environmental NGOs. The restored peatland at Linnunsuo was a prime example of a rejuvenated habitat that was locally driven and now provides a space for ornithologists, students, and the general public to experience an abundance of wildlife in what was previously a desolate site.
Restored peatland at Linnunsuo, and a small block of old-growth woodland surrounded by younger commercial forest; retaining and restoring these sites provides valuable stepping-stones for wildlife
An early warning call?
As with the UK, we heard there is significant uncertainty around the current curlew population figures in Finland; this is a concern given the two countries potentially share as much as 50% of the global breeding population. Although Finnish curlews are monitored as part of farmland bird surveys, as in the UK, productivity data are apparently sparse. Consequently, although the population is thought to be stable overall (albeit with some indications for a decreasing trend on farmland in the south) the long lifespans and high site fidelity of curlews could be masking an unproductive population that is suffering from unsustainable losses of eggs and chicks, particularly in farmed environments due to agricultural operations and predation.
We are considering convening an international conference to share knowledge and experience of how curlew can be used as a flagship species to help understand and tackle major policy issues including forestry, farming, and predator management. An additional aim will be to better understand the uncertainties around survey and monitoring data across the curlew’s European range and identify gaps where additional capability and capacity may need to be targeted.
Finally, we will ensure our findings are shared with UK and Irish colleagues, including those in the Curlew Recovery Partnership Working Group focussing on curlews and forestry, in order to inform ongoing policy decisions on this topic.
The Curlew Action team included Mary Colwell, Russell Wynn, and Ellen Bradley, accompanied by Patrick Laurie (Working for Waders, Scotland) and Barry O’Donoghue (National Parks and Wildlife Service, Ireland). We are grateful to Mikko Alhainen, Noora Huusari, Alicia Jarma, David Jarrett, Tarja and Martti Kettunen, Harri Kontkanen, Nina Mikander, and Tero Mustonen and Kaisu Mustonen for hosting and/or providing data and information during and after our visit. Finally, we are grateful to all Curlew Action supporters for providing funding to enable this fact-finding trip.