It’s hard to imagine a bird that weighs less than a two pence coin travelling all the way from Siberia to end up near my home in Somerset. But that’s exactly what the tiny creature making its way through the dense foliage of ivy and sycamores in front of me had just done.
Pallas’s warbler is one of the smallest of all British birds – just nine centimetres long and weighing a mere seven grams. So it’s difficult to believe that it can migrate at all, let alone fly several thousand miles from the forests of northern Russia all the way to Britain.
It’s often said that these unexpected autumn visitors are “lost”, or “blown off course” – waifs and strays that have taken the wrong turn, or been the unwitting victims of a rogue weather system.
That does indeed apply to rare birds from North America, found in places such as the Isles of Scilly or the Western Isles, which have been swept across the Atlantic on autumn gales. But it isn’t true for those species – like the Pallas’s warbler – that birders call “Sibes” after their place of origin.
Pallas’s warblers used to migrate south and east, to spend the winter in the jungles of south-east Asia. But in recent years a significant minority have changed their migration strategy, travelling west, and probably spending the winter in Spain or northwest Africa. On the way, each October and November, they pass through Britain – with up to 100 being seen here every year.
Not that they are easy to find. This particular bird was spotted by a keen-eyed local birder on the southern edge of Brean Down, a local landmark that juts out into the Bristol Channel at the western end of the Mendip Hills. Amazingly, this was exactly the same site where the very same observer had spotted Somerset’s only other record of this species, fifteen years ago.
Even though the expectant crowd of birders knew the Pallas’s warbler was there, it was not proving easy to see. The bird was doing a feeding circuit with a loose flock of goldcrests, chiffchaffs, long-tailed tits and a lone female blackcap, which meant that we had to wait at least half an hour between sightings. There were the usual false alarms, as a shout would go up, only for our hopes to be dashed when a more familiar bird came into view.
Even when the Pallas’s warbler did appear, the views it gave were frustratingly brief – often just a glimmer of yellow wing bars, or a quick flash of its stripy crown as it flitted rapidly between the leaves.
In case you’re wondering, this elusive little sprite was named after the 18th-century German-born Russian ornithologist Peter Simon Pallas. He also gave his name to a gull, a sandgrouse, a now-extinct cormorant, a volcano, a new kind of meteorite, three species of reptile and no fewer than seven mammals. But when I finally got a decent view of the bird – a two-second glimpse as it flew from one tree to another – I was reminded of its older, and in many ways more appropriate name: lemon-rumped warbler.
Then it was gone; and it was time for me to head off too, for a family walk along the tops of the Mendips followed by the world cup rugby on TV. But I left with a spring in my step, having shared those few memorable moments with a very special bird.
