Название | Curlew Moon |
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Автор произведения | Mary Colwell |
Жанр | Биология |
Серия | |
Издательство | Биология |
Год выпуска | 0 |
isbn | 9780008241063 |
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 detonated and the net will shoot into the air and over their heads, trapping them underneath. They will then be put into holding pens and the geolocators attached.
After a few hours of lugging and digging, everything is set for the next morning.
I leave the guesthouse before dawn; a hard frost covers cars and pavements. Scotland glistens under the streetlights as I drive to meet Bob and his ringing colleagues by the beach. Most of the group, like Bob, are retired, field-fit, passionate bird lovers. The birds are exactly where we hoped they would be, so if all goes well, we’ll have a large catch. Bob, with walky-talky and binoculars, creeps to the far side of the beach and into the bush with the detonator. The rest of us move quietly to the other side to hide in a small patch of woodland. As Bob sends updates about the birds’ position, we sort out who can run the fastest. Once the cannons have been fired, speed will be essential. The quickest sprinters will leave the bags and equipment with the slower ones, then race ahead to retrieve the birds from under the net. The birds would be panicking, so getting them to the safety of the holding pens is vital. This is where I feel I can contribute. Having run a few half-marathons, and being a keen gym-goer and jogger, I confidently put myself forward to go with the advance party. After what seems like an age of whispering and walky-talky instructions, Bob counts down. Five, four, three, two, one – FIRE! An enormous bang shatters the early morning air, followed immediately by alarm-calling birds. RUN! I race off at full speed. My fellow sprinters streak ahead so fast Mo Farah would struggle to keep up. I arrive only just ahead of the ‘slower’ group, who have had to transport all the bags. But there is no time to soothe my bruised ego …
Retrieving the trapped birds is fast and efficient. This well-oiled machine of seasoned bird ringers has been through this routine many times. The birds settle quickly. In all, over a hundred have been caught. The list reads: one wigeon, four teal, one oystercatcher, eight curlew, two dunlin, seventy-four redshank, thirteen black-headed and three common gulls. All are weighed, aged, measured, ringed and released. The curlews also have their geolocators fitted, and, for the first time, I get to hold a curlew in my hands.
Not surprisingly for wild creatures, some species of bird will peck and struggle when held. The more pointed the talons, or sharp the bill, the greater the caution needed. They glare fiercely at their captor with rage or terror. Some are notoriously vicious, like the sea-cliff-dwelling razorbills (the clue is in the name). Curlews, however, don’t do histrionics. Despite having a bill that could take your eye out, they simply sink into your hands and have a look around. They are gentle captives and exude a Buddha-like calm. It is as though being cradled in our hands takes away the pressure for survival for a short while. I am sure this is far from the truth, but the impression they give is one of serenity, not panic.
It is a special, life-giving moment to be so close to birds that I have loved and admired for so long. As I cradle