World Curlew Day is coming up this week and the RSPB are celebrating! RSPB Scotland's Senior Conservation Adviser Dan Brown discusses the kinds of things curlew look for in the habitats they call home.
Habitat management for curlew - cutting, carbon and coos
Curlews have various requirements in terms of the ‘patchwork’ of habitats they choose to call home.
First up is some good-quality feeding habitat… to replenish after migration and fatten up for energy-sapping exploits that lie ahead - advertising a territory, attracting a mate, laying eggs, fending off predators…
Where we work – Strathclyde – such feeding areas include inbye pastures and silage fields. Earthworms, leatherjackets and beetle larvae are all on the menu. These fields receive more in the way of drainage, fertiliser applications and support much higher numbers of livestock. As a result, they have a shorter sward, presumably allowing easier probing of the soil. So, it turns out curlew like to have some more intensively managed fields in their breeding territories.
But the landscape cannot be completely covered in greener and lusher fields. Because next up is a safe nest site, and in our area they nest mostly in semi-natural grasslands where the vegetation is a similar colour to the birds themselves. Camouflage presumably helps avoid the unwanted attention of foxes, stoats - and especially avian predators, which hunt solely using vision.
Lastly, when and if they hatch, for the first couple of weeks the flightless chicks forage in and around wet areas… the edges of floodwaters, flushes or specially-created wader scrapes. Their beaks are not yet fully developed to probe the soil for ‘sub-surface inverts’, so a wide variety of invertebrates running across the ground, like the caterpillars, beetles and spiders, are wolfed down.
Curlew and chick
These 3 habitats are used throughout the breeding season. Even during incubation, GPS tagging of adult birds show that the non-incubating adult will fly some distance during the night to feed on their preferred grass fields.
The reasons for the curlew’s steep decline are fairly well understood.
However, threats may differ in different parts of the country. In the Strathclyde uplands, farmland abandonment is an issue. The wet climate creates many hurdles for local farmers - the challenging economics of farming in the uplands mean that less and less kids are going into farming. The result - an ageing farming population. And since rearing cattle is a physically demanding job, especially in these wet upland areas, a combination of these economic and socio-economic factors has resulted in less cattle in the landscape.
A recently created wader scrape at Common Farm should provide curlews and their chicks with new foraging habitat. Credit: Dan Brown.
This has been happening across the country and for some time and less cattle means less grazing and trampling of the rougher grasses and herbs in the habitats that curlew like to nest in.
The result is tall, thatched stands of ungrazed, uncut vegetation that quickly become unsuitable places for curlew to nest and raise their chicks in.
Cutting and grazing is also necessary to maintain botanical diversity in certain habitats, like this lag fen habitat at Common Farm. Credit: Dan Brown.
So, working with local farmers, in the short-term we are seeking to replicate the grazing that would have taken place in the past. We do this through cutting with various different pieces of equipment to increase and improve nesting and feeding opportunities.
Admittedly, we have been on a bit of a learning curve, as we seek solutions with the local agricultural community in order to identify a set-up which can balance...
Abandoned farmland can lead to extensive stands of tall, species-poor vegetation like this area of soft-rush. These areas can provide opportunities for other wildlife, so the intention is not to completely remove it. Credit: Dan Brown
We think we now have a solution that best fits these needs. Our excellent local contractors, W & J Mair, combine their tractor with a “soucy-trak” system and a flail mower. The result? A large powerful cutting machine that can access wetter ground. This has enabled us to improve areas for curlew across large swathes of rush and molinia-dominated habitat. So far, so good.
Tractor rigged up with the soucy-trak system with a rear mounted flail mower at Netherhill Farm, South Lanarkshire. Credit: Dan Brown
Drone footage of the large-scale cutting at RSPB Airds Moss following work with the soucy-trak. Around 25% of the vegetation is not cut, as curlews like some longer areas in amongst the short vegetation. Credit: Clive Walton.
But is this increasing reliance on cutting sustainable in the longer-term? Depends on your perspective - but I don’t think so. Recently, we have been in discussions with farmers and representatives from the National Farming Union of Scotland and the Scottish Beef Association to consider how if we might reverse the decline of cattle in the locality. Like lapwing, snipe and golden plover, our wading birds have evolved in our human-influenced landscapes, and certain farming systems provided them with all their habitat needs. However, the future of these farming systems is shrouded in uncertainty.
Future conservation solutions therefore appear to overlap nicely with local farming interests and with the need to consider climate change – another hot topic relating to livestock farming practices.
We are currently working with some farms and estates that produce good-quality beef, capture carbon through restoring their degraded peatlands and help maintain habitats for threatened wildlife. We need more of it and we need to ensure these farming systems have a sustainable future. Surely such a model constitutes a sustainable food production that most of society can support – and keep farmers farming and curlews calling.
Cattle grazing along the Duneaton Water in South Lanarkshire. Cattle numbers have declined in Scotland in recent decades, but can play a crucial role in providing the habitat requirements of breeding curlew. Credit: Dan Brown.