Were I not a human being I would want to be a bird – how lovely it would be to fly! Apart from being able to go from place to place quickly and efficiently, could there be anything more liberating than taking to the air without a thought and then flying freely before returning to terra firma? And for exhilaration, how about circling high in the sky supported by a current of warm air?
But setting aside these shorter flights, there would be the adventures when taking ‘migratory’ journeys, sight-seeing as one flies across oceans and continents. Indeed, it was one of Europe’s migratory stalwarts – the tiny sedge warbler – which inspired this blog. Holding him or her in my hands – the two genders are indistinguishable – before it flew off to sub-Saharan Africa was very special (see illustration).
That birds migrate was known to the ancient Greeks, but it took millennia to discover exactly what went on. Some theories were amusingly whimsical: swallows, for example, overwintered on the moon! Now however, in large part thanks to ringing, we know more. Through a worldwide network of ringing centres, birds are caught and tabbed using uniquely-numbered metal or plastic rings attached to a leg or a wing. The ringed birds are then set free and if re-captured their whereabouts and condition are noted and entered in a data bank for sharing globally.
I met my sedge warbler three weeks ago at a ringing centre just near our home in Brittany. The centre, an inauspicious wooden hut, is surrounded by acres of reed beds and marshland. On one side is the Atlantic Ocean, on another the brackish Trunvel lake, the remainder is farmland. With its rich plant life and its abundance of flying insects, for hundreds of thousands of years the area has served as a home for local birds and a staging post for birds migrating between Scandinavia, Europe and Africa. Fortunately, this unique and irreplaceable bird habitat is now part of a nature reserve, with the nearby beach and its immediate hinterland similarly protected.
For our visit – I went with a birder friend – we arrived at the centre soon after dawn. Work had started hours earlier with a handful of volunteers and Marie, the centre manager, collecting birds and logging their details. Each hour the volunteers went out in their chest-high waders to bag the birds that had been trapped in the fine nets criss-crossing the reed beds.
The centre, which deals primarily with small birds, was established in 1988 and, weather permitting, now rings birds every day from early July to the end of October. In a good year the centre rings around 6000 birds; this year, possibly due to climate change, the figure is expected to be much lower.
When brought out of its bag, each bird is checked for the presence of a previous ring, is weighed, has its feathers inspected, its leg and wing length measured, its overall condition assessed, its belly checked to see its level of nourishment and, finally, it is ringed. In all this, everything including the new or extant ring number, is logged meticulously.
During our visit we were shown how, when handled properly, most birds happily submit to being examined. Well, all but the blue tit who we saw pecking at its handler and wriggling throughout! As a species, blue tits have ‘attitude’, as Marie put it.
After an hour or so at the centre, I asked Marie if I could hold one of the ringed birds before it was set free. She agreed, deciding it should be a sedge warbler which she described as one of the more robust of the small birds. I would first have to learn how it should be handled.
Ringing continued and three bird-bags later it was ‘my’ sedge warbler’s turn. According to all the measurements it was healthy, weighed 12 grammes, and looked fit and ready to set off for Africa. It had probably flown in from Norway and if resident for a while at the centre it would have taken up to nine days of feeding to replenish the fat stores and to build up adequate muscle bulk for a successful flight south. Now, with help from the elements, within four days it could be half way to Sub Saharan Africa in one flight.
Being handed the sedge warbler, being entrusted with such a tiny bird as it looked around but otherwise stayed very still, was magical. Opening my cupped hands and watching it fly up into a bush and then set off on its 10,000km journey was somehow humbling. Odd as it may seem, I almost felt part of me would be flying with it.
And incidentally, while it has long been believed that the life expectancy of a sedge warbler is 2-3 years, through ringing it is now known that an eleven year old is still flying long distances.
The illustration is a photo of ‘my’ tiny sedge warbler with its head peeping out between two fingers of my cupped hands. It had just been ringed and would soon be off to Africa.
For helping me write this blog I would like to thank Jeni, Marie, Monica, Rohan and Vivien.