BTO migration blog

Spring and autumn are exciting times for anyone who watches birds. Here on this blog we will make predictions about when to expect migrant arrivals and departures, so that you know when and where to see these well-travelled birds.

Friday, 29 August 2014

Easterly airflow brings in some scarcities

The last few days have seen some easterly airflow from the continent with the resultant arrival of a few classic late August/early September migrants.

Amongst the common migrants, Whinchat has featured strongly. Willow and Sedge Warblers have also begun to move in numbers and the first real movement of Redstart, Pied Flycatcher and Yellow Wagtail is underway.

The BirdTrack graph for Redstart above shows this second reporting peak as birds begin to move out. 

With easterly airflow at this time of the year there is always going to be some scarcity interest and this was definitely the case. Barred Warbler, Greenish Warbler, lcterine Warbler, Wryneck and Common Rosefinch were bang on cue but the Fieldfare that was seen coming in off of the sea at Sheringham on 28 August was particularly early.

Waders have continued to move through but not in the numbers that might be expected. July saw reasonable numbers of adult birds on the move but the number of juvenile birds has been low. Maybe the breeding season further north has been a poor one, or might it be that the fairly consistent westerly airflow through most of August has meant that they have been moving through on the other side of the North Sea?

There is some nice evidence of birds crossing the North Sea in the last few days. The deck of a research vessel in the southern North Sea has seen a few Pied Wagtails, a couple of Garden Warblers and a lone Reed Warbler, read more here

Swift migration is well underway with the majority probably already in southern Europe, although small numbers are still being seen migrating through coastal watchpoints.

The BirdTrack reporting rate for Swift

What can we expect during the next few days?

Westerly airflow, becoming light during the early part of next week, won’t quite result in a similar arrival of scare passerines but we might see a few Pectoral Sandpipers and possibly the first Buff-breasted Sandpiper of the autumn courtesy of Hurricane Cristobal that will track across the Atlantic before heading north towards Iceland later this weekend.

The lighter winds and high pressure early next week should encourage some of our common migrants to move and we could see an increase in Wheatears, Wagtails and warblers at migration watchpoints.