It is 8 years since I drove for hours to see a specific bird. The fact that on that occasion Ian and I were nearly killed by another driver ploughing headlong into the front of my car on the A148 in Norfolk, may have come into my decision, but the thrill of the chase was fading anyway. I realised that I found it much more satisfying to find my own birds, so I covered my Oxfordshire local patch around Cuddesdon and visited Lundy Island in the autumn for my migration kicks. But this autumn has seen a truly spectacular ornithological event. A rare and beautiful species that breeds in Siberia and winters in central China has reached us. In fact, a species only recorded 15 times in the whole Europe in the last 150 years has reached us in unprecedented numbers. To date 146 Siberian Accentors have been recorded across Europe between 4th and 23rd October 2016, including the first 8 British records. Surely the quickest turnaround from first record to many since the first Collared Doves arrived in Norfolk in the late 1950s? With new birds being discovered on a daily basis, online maps of Siberian Accentor sightings quickly became outdated (see full map here):
This irruption raises a number of questions. It seems unlikely to be due to reverse migration. The random chance of a genetic abnormality causing a bird’s migratory compass to propel it far from the usual migratory routes for that species is not going to occur in over 100 birds simultaneously. There was talk on the east Yorkshire coast that the harvest in Russia this summer was the best in a generation. If true, would good conditions for agriculture also benefit breeding passerines? Even if it did, why should so many migrate so far from their usual route from Siberia to central China and end up so far west? Could the mass displacement of so many Siberian Accentors be indicative of some unknown environmental issue on their breeding grounds?
Siberian Accentors are thought to have expanded their breeding range west toward such the Ural Mountains. Perhaps a good breeding season has produced an exceptional number of birds in the far west of their range? Then these young migratory birds are exposed to a prolonged period of wind propelling them towards Western Europe. A prolonged spell of high pressure stretching from central Russian into Scandinavia, combined with winds blowing from central Asia into Western Europe during most of early October may have assisted the irruption. This graphic from 7th October illustrates the prevailing weather conditions (see here for the full animated map). An area of high pressure (blue) stretches across all of central Russia, with winds blowing from east to west (green) picking up from the Urals, blowing straight into the Baltic Sea, southern Sweden and onto the northern east coast of the UK: 
From the moment of the discovery of the second British Siberian Accentor last Thursday near Spurn Point, East Yorkshire I realised that I wanted to be part of this remarkable event. I was not alone, it is estimated between 3,000 and 4,000 people traveled to Easington to see this bird during it’s six day stay. For me, what it represented was almost as important. Not merely the epic feat of a long migration from the other side of Eurasia to East Yorkshire, but the fact that hundreds (possibly many hundreds, how many were missed?) of Siberian Accentors were simultaneously entering western Europe in a unique ornithological event. The bird itself was a cracker. An early online description of it being like a “Dunnock doing Bowie” is spot on: it is the head pattern that sets this birds apart, a feast of tan and black stripes that the bird showed off to great effect whilst tossing leaves around during its search for insects:
The collective noun for Dunnocks is, apparently, a “Jovial of Dunnocks”. If this is the case, then a “Joy of Accentors” would seem appropriate for the pleasure and interest that this remarkable event has brought to birders all over Europe. And for me, I had a fabulous day out at Spurn Point, seeing a feast of Siberian breeding warblers including Yellow-browed, Pallas’s and Radde’s Warblers that made up the supporting cast. With the winds remaining in the east, this remarkable autumn is set to run and run.