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 12 October 2012

Migration stalls a little

After the rush of American birds in the west last weekend, things have quietened down somewhat.

Right now finches should be keeping ‘vis miggers’ (visible migration watchers) very busy but for the most part visible migration has been fairly disappointing for them. There has been the occasional busy period mixed in amongst almost birdless days at some migration watchpoints.

Goldfinch by John Harding

The finch counts at Spurn Bird Observatory illustrate this perfectly. On 8 October, around 2,000 finches were counted flying over, including 1,411 Goldfinches. The finch count for the very next day couldn’t have been more different with only five Bramblings and no goldfinches counted, and very little else on the move. With reports of a failure in the beech mast crop in Scandinavia, we could be in for a large arrival of Bramblings any day. The BirdTrack reporting rate shows the peak arrival time for this beautiful finch well.

At this time of the year a bit of east in the wind generally triggers common migrants to get moving, couple this with the odd shower or two and any birds moving overhead can be grounded. These were just the conditions that Portland Bird Observatory experienced on the same day that Spurn had its large finch movement. On 8 October around 200 Robins were grounded at the Bill, and were much more numerous around the centre of the island. The weather also grounded the first noticeable movement of thrushes, which included 50 Blackbirds, 40 Song Thrushes and 25 Redwings.

The easterly winds from the early part of this week will turn westerly as we go into the weekend, bringing heavy rain to the south west. However, on Sunday the winds will again turn easterly for a short time and maybe prompt a large movement of finches and the first big movement of thrushes, (this weekend could be a good one to take part in the Winter Thrushes Survey) and possibly Skylarks.

Gannets by Edmund Fellowes

If you are looking at the sea this weekend then the south west will be the place to be on Saturday but east coast seawatchers might get higher returns for their efforts on Sunday. Common Scoter traditionally begin to move in large numbers around mid-October and there is always a chance of the odd Velvet Scoter mixed in with them. Gannets should feature highly and Red-throated Diver numbers should increase and include the odd Black-throated and Great Northern Divers.

As for rarities? We are just coming in to the peak period for the rarity mecca that is the Isle of Scilly and with a low pressure system arriving from across the Atlantic tomorrow morning an American passerine has to be on the cards for the islands. Whilst I still fancy Black-billed Cuckoo for this autumn, the first American Redstart for the archipelago would set pulses racing.

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