Yellow-browed warbler is a common breeding species in temperate Asia occuring from the Urals in the west to eastern Siberia. The species winters in south-east Asia and is common in, for example, Thailand and Malaysia. This migration means that birds cover distances of up to 5,000Km to travel from their breeding grounds in the north to their wintering grounds in the south. It is likely that the birds that occur in the UK originate from the western areas of the breeding range meaning a distance of around 3,500Km to reach our shores.
Conditions for migration from the breeding grounds have recently been ideal with a high presssure centred over central Asia. This high pressure had an easterly air flow along its northern edge encouraging drift of birds as they migrated south. This easterly airflow and fine weather extended all the way to the UK facilitating this drift. Fronts associated with a low pressure 1011 are likely to have result in the grounding of these migrants as they arrived from the east.
Synoptic Chart for 21st September 2012
The yellow-browed warbler is one of my favourite autumn birds and little can beat the thrill of finding this species as it flits amongst the autumnal leaves of willow and sycamore.
By the 24th September the first yellow-browed warblers reached the Isle of Scilly perhaps indicating their westward spread from their east cost arrival point.