In the early 2000s, I remember being out on a National Trust walk for young naturalists on a Surrey heath and being told by the ranger leading the event that the habitat before us was "rarer than rainforest". The sandy landscape, peppered with the bright yellows of flowering gorse and dull purples of heather, felt almost as exciting as a rainforest for a young kid fascinated by wildlife, with elusive reptiles, specialist birds, rare plants and all manner of insects out there to be discovered.
There's no doubt that heathlands form some of the wildest landscapes in the lowlands of Britain, acting as oases of space and wilderness in an otherwise increasingly crowded environment. Their importance cannot be overstated – lowland heaths are a Biodiversity Action Plan (BAP) habitat after all – and they are home to many plants and animals whose range has decreased with the disintegration or disappearance of heathland during the last few centuries. However, despite the clear significance of lowland heaths, threats to them remain all too real and indeed are heightening in our warming climate.
Lowland heath is one of the most important habitats in England (Oliver Smart).
In a broad sense, a tapestry of wet, damp and dry habitats make up lowland heathland, which is always found below 300 m altitude. More often than not they are on low-quality, acidic soil and dwarf shrubs, such as heather and gorse, are typically present. On infertile, well-drained sands in the drier and colder east of Britain, relatively few plant species persist and Ling Heather and European Gorse predominates, with lichens able to flourish. As the climate becomes increasingly damp towards the west, Dwarf Gorse and Bell Heather become frequent, then Western Gorse and Bristle Bent and Purple Moor-grass. Where peat or mineral-rich soils are susceptible to waterlogging, wet heath comes into play and this can be especially diverse.
Human help
Heathland has a long history of human management, with most developed around the time of the Stone Age, some 3,500 years ago, when trees were removed and kept from regrowing due to grazing or burning. These traditional heathland activities have played a vital role in stalling succession and allowing heathland to persevere over the centuries. That said – and despite Britain still claiming some 20% of the world's lowland heaths – a whopping 80% has been lost on our isles since 1800.
Lowland heath occurs across continental Europe, but the British heaths are especially important in conservation terms. This is in part because they form such a large proportion of the European resource, including wet heath and maritime heath, which are both relatively rare. Lowland heaths need human intervention to survive and in the modern era, generally, this is the work of conservationists. There are, however, notable exceptions, such as the New Forest, where the tradition of common grazing by farmers persists.
The habitat is scattered across Britain, although it is largely absent from Scotland and North Wales. The most significant areas include Cornwall, Devon, Dorset, Hampshire, Norfolk, Staffordshire, Suffolk and Surrey in England and, in Wales, Pembrokeshire, West Glamorgan and West Gwynedd. There are small areas in Kent, Lincolnshire, Sussex, Yorkshire and the Midlands, too. Many premier heathland sites are well-known to the British birder as they hold particularly desirable and localised species.
Heath inhabitants
Perhaps the most symbolic bird of British lowland heaths is Dartford Warbler. This skulking Curruca is at the northern edge of its range in Britain and, being a resident warbler, can be severely affected by harsh winters, especially if there is prolonged snow cover. Its British range has historically retracted due to the loss of heathland, and particularly severe winters in 1939-40 and 1962-63 brought the small population to its knees. Modern-day crashes have occurred, notably during back-to-back cold winters between 2009 and 2011. In more recent years, however, there has been a gradual increase and stabilisation, even if the latest Rare Breeding Birds Panel (RBBP) report (2018) noted a decline from 1,600 territories to 1,133 (not helped by the 'Beast from the East' that year). With some 373 territories estimated in 2018, Dorset remains the most important county, with Surrey notching up 325 and Hampshire 233. The only other county to host triple-figure numbers of territories was Suffolk, with 112.
At the northern edge of its range in Britain, Dartford Warbler is an iconic bird of lowland heaths, with a limited national distribution (Kit Day).
The birds' strict association with heathland is reflected in where they build a nest – either gorse or heather (hence the old English name 'Furze Wren'). An increasingly warm climate is thought to be behind their expansion into higher altitude habitat, more northerly areas and away from the core of the range. This will likely continue.
However, future climate-based projections for Europe suggest that, by 2080, more than 60% of the current European range may no longer be suitable. There is evidence that this is happening already, with some severe declines in Spain and France. For this reason, the species is classified as Near Threatened on the IUCN Global Red List. If the declines in southern Europe continue, the UK will become increasingly important for global conservation of this species.
Another lowland heath specialist is European Nightjar, though it can also be found on moorland and upland heath. This species is not threatened internationally, and the British population is at some 4,600 pairs, but a gradual decline means it is Amber-listed. This iconic species is synonymous with warm, midsummer evenings on a lowland heath – after the sun has set, bursts of low-frequency churring from males, followed by a responding female (with its curious kwit call), wing displaying and silent aerial feeding make for an evocative experience. In Britain, commercial forestry has created new habitat for European Nightjar, but these gains are temporary, meaning heathland remains crucial for the species.
Midsummer is the time to catch up with another special heathland bird: European Nightjar (Helge Sorensen / www.agami.nl).
Woodlark is another denizen of lowland heaths, though this species is slightly more versatile when it comes to habitat and has a more northerly range than Dartford Warbler, reaching Staffordshire and Yorkshire. Like Dartfords, Woodlark has enjoyed an increase in recent decades. A series of systematic national surveys found 241 pairs in 1986, which increased to 1,633 in 1997, followed by an 88% increase to 3,064 pairs in 2007.
Although more dynamic in its habitat choices than Dartford Warbler, Woodlark is another species heavily associated with heathland, especially in southern and eastern England (Kit Day).
Stone, pine and bog
Eurasian Stone-curlew is another specialist species of British heathland. However, unlike the previous three species, it is not strictly associated with the habitat and indeed, most southern and western lowland heaths are not suitable. It is in eastern counties, where such habitat can be dominated by grass and lichen heath, where stone-curlew makes its heathland home – Weeting Heath in Norfolk is perhaps the best site in the country to see this enigmatic wader.
There are plenty of other species associated with lowland heaths. Where there is a suitable amount of pine, Eurasian Hobby may breed in an old corvid nest, while Common Redstart will find a suitable hole in which to nest. Heathland with a wooded component, ideally birch or oak, holds breeding Tree Pipits, which themselves attract Common Cuckoos. European Stonechat is often found breeding in similar habitat to Dartford Warbler; the latter species has an odd habit of following the former around, especially outside the breeding season. The Red-listed Common Linnet is a big user of dense gorse to nest in as well.
Heaths with areas of bog provide plenty of Odonata prey for Eurasian Hobby, which will breed in a tall pines on sandier ground (Tim Melling).
Common Redstart is another species that is quite at home on a lowland heath (Ian Livsey).
Where there is bog, breeding waders may persist, with a handful of Eurasian Curlew still remaining on lowland heaths. Common Snipe will use such habitat, too – both these waders are rare breeders in southern England these days and their continued presence on lowland heaths demonstrates the importance of such sites.
As well as all these specialist breeders, there are specialist winter visitors. Perhaps the most obvious is Great Grey Shrike – during the winter of 2020-21, some 14 lowland heathland sites in England hosted the species and indeed many of these are traditional locales for it. Raptors too visit in winter, usually species that have moved from comparable habitat at higher elevation, such as Hen Harrier and Merlin.
There are examples of rarities that use similar habitats in Europe being drawn to such areas in Britain – a Western Subalpine Warbler at Westleton Heath in 2019 and, in 2018, Woodchat Shrike at Roydon Common and Red-backed Shrike at Thursley Common are recent cases. It's perhaps no surprise a reptile-loving Short-toed Snake Eagle in 2014 included the New Forest, the Brecks, Thursley Common, Ashdown Forest, Morden Bog and Arne RSPB on its grand tour of England – all heathland sites. Perhaps some of these species are an indicator of what our heaths will look like decades in the future?
Perennial problems
Such specialist habitat requires careful management. The encroachment of trees and scrub, avoiding homogeneity of ages of certain vegetation, suppression of appropriate soil disturbance, drainage and suitable grazing all need to be controlled. This is to a backdrop of increasing development and fragmentation of habitat.
It's a hard job to keep a lowland heath optimum, and this is without an increasing worry in modern-day Britain: fires. In my home county, heath fires of some form have become almost annual – a severe blaze at Thursley Common, and a lesser one at Chobham Common, in 2020 have been followed this year [2021] by a smaller incident at Hankley Common. Such dry landscapes, with oft-waxy plants, are susceptible to fire and our warming climate only heightens the risk of a devastating breakout. The aftermath of a blaze can sometimes be good for Woodlarks, but not much else.
Human disturbance is another increasing issue. Horses' hooves churn up sandy heathland tracks, making the habitat unsuitable for certain invertebrates. Heather is very susceptible to death from excessive trampling, too, while soil enrichment, especially from dog faeces and urine, can encourage lush vegetation beside paths and thus ruin the crucial natural boundary between vegetation and open sand. Dogs off leads pose great threats to ground-nesting birds, and this includes heathland specialists such as European Nightjar and Woodlark.
European Stonechat can be the most obvious species on a heath, as it regularly chooses a conspicuous perch from which to sing (Gordon Speirs).
There’s no doubt many fires are started by humans, intentionally or not. Certainly, there are heaths near me that are more akin to a city parks at times, with huge volumes of people straying far off paths, dogs running amok, BBQs on the go and so on. This issue is one that causes great concern for the long-term survival of lowland heaths.
The birdlife on a lowland heath is a small slice of the biodiversity found at these remarkable habitats. Many special reptiles, invertebrates and plants are found – too many to mention here – but things like Silver-studded Blue, Emperor Moth, Sand Lizard, Smooth Snake, Round-leaved Sundew, Pretty Whin, Southern Damselfly, Ladybird Spider and Green Tiger Beetle will captivate any birder for more than a moment.
Midsummer is the finest time to be on a lowland heath. So why not take a trip to one of these special sites soon – you won't be disappointed.
References
Eaton, M, and Holling, M. 2020. Rare breeding birds in the UK in 2018. British Birds 113: 737-791.
Farrell, L. 2008. The different types and importance of British heaths. Botanical Journal of the Linnean Society 101: 291-299.
Forestry Commission. 2014. Lowland heath: www.forestry.gov.uk/forestry/lowlandheath.
Michael, N. 1996. The lowland heathland management booklet version 2.0. English Nature Science.
Natural England. 2015 European heathlands: www.naturalengland.org.uk/ourwork/conservation/biodiversity/ protectandmanage/europeanheathlands/facts.aspx.
Shaw, P J A, Lankey, K, and Hollingham, S. 1995. Impact of trampling and dog fouling on vegetation and soil conditions on Headley heath. London Naturalist 74: 77-82.
Tubbs, C T. 1991. Grazing the Lowland Heaths. British Wildlife 2: 276–291.
Wildlife Trusts. 2014. Lowland heathland: www.wildlifetrusts.org/wildlife/habitats/ lowland-heathland
- This article was first published in the June 2021 issue of Birdwatch magazine.
