Can we halt the decline in curlew?
Our April conservation blog from Tracy Johnson, Nidderdale Moorland Group Co-ordinator.
For those of us who live and work in the uplands of Northern England and Scotland it is a common sound of spring and summer, an iconic call that signals the coming of longer days and hopefully, warmer weather, as winter turns to spring.
Yet for those who live in lowland areas of Southern England, it is a call of spring that a generation growing up today have never heard.
The haunting, bubbling call of the Curlew is still an emotive sound of spring and summer in the northern upland’s, but this was once a sound heard across many other habitats, including lowland regions of the UK and Ireland away from our managed moorlands, but a sound now lost in many areas of the UK as our largest wader continues to decline at an alarming rate.
About 25% of the global population of Eurasian Curlew are found in Britain and this number swells every winter as birds from Finland, Russia and other European countries come here to spend the colder months of the year in our milder climate.
The British population of breeding Curlew is of global importance, but even here these iconic birds are now facing the real risk of extinction as a breeding bird. We have lost around 65% of the population of our largest breeding wader since 1970. In many lowland areas and unmanaged moorlands these birds are already near or locally extinct. It is estimated that there are less than 300 pairs now remaining below Birmingham, including on southern moorlands such as Dartmoor and Exmoor and the New Forest heaths, areas once a stronghold for these birds.
Curlews are ground nesting birds of open habitats that include damp areas for feeding and places to safely nest and rear their young away from disturbance. They have a very good chance of surviving once they reach adulthood and can live for over 32 years, but many are not reaching fledging age, never mind adulthood, they are lost as eggs and young chicks, mainly to predation, both avian and mammalian.
The UK Curlew population is continuing to decline and it’s breeding range is contracting from lowland areas of the UK to the northern uplands, from the Peak District, South Pennines, Forest of Bowland, North Yorkshire and North York moors to the Cheviots and Scotland, all areas that now hold the highest densities of UK Curlew populations.
Ideas such as protecting nests with electric fencing won’t ever stop avian predators nor protect the chicks once they leave the nest after hatching and start wandering in search of food. Curlew chicks are precocial, they walk and feed themselves within 24 hours of hatching, moving away from the nest site whilst the parents keep watch for any signs of danger approaching.
With mammalian predators, which include the Fox, Badger, Stoat, Weasel and avian predators including Carrion Crows, Lesser Black Back, Greater Black Back and Herring Gulls, Red Kites and Buzzards, the odds of successfully rearing eggs and chicks to adulthood are very much stacked against these vulnerable, ground nesting birds. Gulls, especially, are proving a large problem for Curlews as these birds have gradually moved inland to both feed and breed due to problems around their own coastal habitats and loss of traditional feeding areas at sea, and this also includes the inland closure of landfill sites as we have moved to waste incineration.
Traditional scavengers such as the Common Buzzard, Red Kite and Carrion Crow have also increased their predation of vulnerable ground nesting species due to the loss of dead stock on farms and the noticeable drop in the UK rabbit population caused by RHD2 disease which has reduced traditional food resources for these birds and as the populations of these top predators continues to increase, so the pressure on other vulnerable species such as the Curlew has increased dramatically as the predators switch to higher predation levels of vulnerable ground nesting specie’s.
Modern agricultural practices such as silaging mean that fields are drained and converted to fast growing grasslands that can be mown several times a season, replacing traditional hay meadows only mown once a year, and with a pair of Curlew requiring approximately 10 weeks to successfully rear and fledge their chicks, many are now lost due to accidents with modern farm machinery.
One of the greatest threats to Curlew’s habitats today is alongside rewilding landscapes, the push to plant trees and create woodlands which are the ideal habitat for predators of the Curlew and other ground nesting species and which also use up and dry out land that was once an open and damp habitat, vital for Curlews and many other waders.
Curlews prefer not to nest within 500 meters of woodlands, and as site faithful breeding birds, returning year after year to the same nest site or area of their birth, this loss of habitat and increase of predators from afforestation and rewilding is exacerbating and driving the loss of these birds at an alarming rate.
It has been estimated that to just maintain the current population, not increase it, we need these birds to successfully fledge a further 10,000 chicks each year in addition to those already reaching adulthood in the wild population.
Head starting Curlew eggs and chicks is an expensive technique that is being trialled at present, but it is not the answer to increasing the population as the 10,000 extra chicks needed now to maintain the present population cannot be reared this way and any birds successfully returned to the wild from head starting projects will still struggle to raise any young unless all the issues facing the Curlew today are addressed, including effective predation control.
In recent years the plight of the Curlew has become more widely recognised and now several groups and organisations have been formed or come on board to highlight the issues facing these iconic birds. However well-intentioned these groups are, unfortunately clipboards, surveys and monitoring projects will not stop the dramatic free fall we now see in the Curlew population.
Today the Curlew is seen as the bird of highest conservation concern in the UK. On the Red List of Conservation Concern (BOCC5) and the global Red List (as Near Threatened) since 2015 (www.iucnredlist.org) Current estimates suggest that there are approximately 58,000 breeding pairs in the UK, but these birds are not distributed evenly. It is no surprise to see the highest densities in areas which include grouse moor management as the Curlew has been found to be up to five times more successful at rearing young to fledging in these areas, benefitting from the habitat management and predator control work of gamekeepers.
Predation control is an emotive subject for some people, but alongside habitat management, it is also one of the main ways to ensure the Curlew, and many other vulnerable ground nesting species, have a future as a breeding bird across many habitats in the UK, both in the uplands and lowland areas.
Considerable efforts are now required to halt the continuing decline of this iconic wader. We know why these birds are declining, we know where the greatest losses are and more importantly, we know what these birds require now to stop this decline. It’s time to stop monitoring the Curlew into extinction.
For more information go to www.gwct.org.uk A Future For Curlew and Waders on the Fringe factsheets are available from the GWCT.