yet again, gain the depressing title of ‘failed breeders’ and arrive back on the coast way ahead of time. They will have lost the chance to produce young once more. The world is an increasingly uncertain place for them, as it is for many other birds.
All over the Earth the great pendulum of bird life swings to and fro in time to the beat of the seasons. Some migrants are well studied, but others are only just revealing their secrets as different kinds of tracking devices are developed and become smaller, lighter and more reliable. Hopefully, we will learn more about curlews in the future. It is amazing how little we know about their lives, particularly considering they were once so numerous and widespread. The everyday rarely gets the attention it deserves, until, that is, it becomes increasingly hard to find.
Organic farmer, naturalist and former wildlife camerawoman, Rebecca Hosking, described to me on Facebook her experience of catching a glimpse of winter curlew in Devon:
The north winds blew a pair of curlew to the farm this morning. Their unmistakable calls rooted me to the spot, as I watched them spiral downward to feed in one of the lower meadows. To me, their cry is the essence of wildness, both haunting and beguiling. I was astonished at the level of emotion those bubbling trills invoked. Pure joy and excitement, for this was the first time I’ve ever heard them at Modbury. Yet that joy soon turned to sorrow and lament, knowing how drastic their decline has been. My knee-jerk reaction was to run and find Dad so he too could hear. As we stood in the garden listening, the pair lifted back to the sky, calling their plaintive, lonely ‘cour-leees’ as they circled overhead. I looked across at Dad to see his reaction; his eyes were beginning to well, ‘I haven’t heard that bird in this valley in over 40 years,’ he said. We watched them slowly reel their way towards the coast, until they flew out of sight.
A fifth of Europe’s curlews visit the coasts and estuaries of the UK and Ireland in the winter, a number that is steadily declining. It is an awesome responsibility to hold the fate of these world travellers in our hands. Although most of the birds are unstudied, there are some hotspots for research, and The Wash Wader Ringing Group has been busy fitting identification rings onto the legs of curlews for decades. It has amassed some interesting results. Most of The Wash curlews breed in Scandinavia, France and Germany; only 25 per cent are British birds that stay all year round. Some visitors travel a long way. One curlew ringed in The Wash in September 2000 was shot in Russia the following May, over 2,000 miles away. It was fifteen years old. Surprisingly, this is only middle-aged. A bird caught in Lincolnshire in 2015 was twenty-nine, nearly matching the record for longevity which goes to one found dead in the Wirral in 2011 at the grand old age of thirty-two.
Thankfully, more projects are getting under way to understand the lives of these wonderful birds. In the weeks leading up to my walk I wanted to find out more about winter curlews, and so in early February I made my way to the northeast coast of Scotland, to the Moray Firth, where I had been told interesting things were happening.
I arrive to bright sunshine and a clear blue sky. A period of glorious winter weather is gracing eastern Scotland. After a few hours of searching, Bob Swann and I find curlews roosting on Bunchrew Bay, near Inverness, on the Beauly Firth. Bob is a retired teacher, wiry and strong, passionate about nature and with an encyclopaedic knowledge about sea birds in particular. He is a legend in the world of Scottish bird ringing, and along with others in the Highland Ringing Group, has contributed immeasurably to our understanding of bird life. I couldn’t be in better company.
The Moray Firth is another important wintering site for many species of wading birds. Numbers in excess of 36,000 spend the winter in and around its many inlets and lochs. Dunlin, redshank, golden plover, lapwing, ringed plover, sanderling, purple sandpiper and knot join curlew here, many coming over from Scandinavia. The Highland Ringing Group has been monitoring numbers and fitting identification rings onto the legs of curlews for many years. The results show that all of the curlews wintering in the Moray Firth are either Scottish or Scandinavian birds. Overall, there are more males than females (58 per cent male to 42 per cent female), and some specific sites are predominantly male. Very few juveniles have been ringed, only 4 per cent, indicating that either they roost elsewhere or, far more worryingly, there are very few around to ring. Over the years birds have either been spotted or re-caught in the same places. The Scottish curlews – and it seems to be the same everywhere – are very much creatures of habit, returning year on year to the same places.
A simple identification ring fitted onto a bird’s leg is one way of getting information about an individual, but as technology advances we are able to resolve mysteries about their lives – which was impossible before this digital, data-streaming age. For example, as tracking technology gets smaller and lighter, we can now vicariously tag along on the journeys they make throughout the year. On 31 March 2009 Bob was part of a team that caught a female curlew at Bunchrew Bay and fixed a satellite transmitter to feathers on her back. It is rather cumbersome-looking with a long antenna attached to a small black box (a couple of centimetres squared), but it is light and only in place for a few months since it falls off when the feathers moult in the autumn. As the bird was caught at the end of March, the suspicion was that this was a Scandinavian female. We know that curlews breeding in northern Europe remain on their Scottish wintering grounds longer than local birds, waiting for milder weather to melt the frozen northern lands. By the middle of March, British birds are already on the hills, preparing to nest.
Once she set off, the transmitter sent back data every few days over the spring and summer. Technology now allowed the Highland Ringing Group to track one bird’s annual migration through data streamed to a computer screen.
The female left Scotland in mid-April and flew over the middle of Norway, passing through a gap in the mountains. After a few days’ rest in Sweden, on the Gulf of Bothnia, the data then showed a flight across to Finland. For fifty-three days she was stationary, long enough to nest and raise young. The return trip to Scotland took a different route via the southern tip of Norway, before crossing over the North Sea to arrive north of Aberdeen by 1 July. Eventually, by 5 July, the female arrived back where she started, on the Beauly Firth.1 Thus we have a circular migration, not a straight line back and forth, showing that curlews depend on vast areas to support them through the year and all these places are important for their survival. It’s interesting that the satellite transmitter confirmed that this curlew was away from Scotland for no more than three months of the year, highlighting that the birds we call ‘northern European’ are actually spending three-quarters of their time in the UK. Protecting wintering areas around our shores is therefore just as important as safeguarding their nesting sites.
The project provided an insight into the year of just one curlew, so plans have been drawn up to expand the database. The next phase, which I was here to see, involved catching many more curlews and fixing smaller, cheaper devices, called geolocators, to the rings on their legs. These marvels of technology collect data and store it onboard the locator, rather than constantly streaming it back to a computer. Geolocators record light levels so that sunrise and sunset can be worked out and the birds’ positions identified. Cheap and less cumbersome, for sure, but in order to retrieve the data the same birds have to be recaptured later in the year and the geolocator removed, although, as curlews are so site-faithful, that is not such a tall order as it sounds.
The first step involves catching lots of curlews. If you are not au fait with cannon netting, and just happen to come across it in action, you might think something heinous is going on. It involves laying explosives, creeping about in the dark, setting off very loud bangs and trapping frightened birds under nets, but it is all for a good cause.
The proposed curlew catch on Bunchrew Bay requires preparation. A long net, with two firing cannons attached to the ends, is buried in the beach where the curlews are known to roost overnight. The detonator is hidden in bushes and attached to the cannons by long cables. When the birds are standing peacefully, the explosives will be
