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, 17 May 2013

Spring not so Swift

To report that Swifts have arrived en masse might not seem that unusual for mid-May but their arrival this year has been far from the norm. The first arrivals were particularly early, Shetland recorded its earliest ever Swift on Fair Isle on 16 April, with the first in the country being on 23 March on St Agnes, Isle of Scilly. It wasn’t until the first few days of May that they became more widespread, however. But, when they did arrive it was in much smaller numbers; when Swifts arrive they normally arrive everywhere at once. That didn’t happen and it took a second wave of arrivals on 15 May for them to become truly widespread this spring.

The topsy-turvy weather has also held back Spotted Flycatchers, which are now running over a week later than normal.

So, where are we at so far this spring? Many of the early migrants that were running two to three weeks late have now caught up, Sand Martin is one of these that was very thin on the ground a few weeks ago. For some ID tips to separate these and other hirundines, take a look at the latest ID Video: Hirundines and Swift.  The warblers have pretty much caught up as far as arrival is concerned but are running a bit late when it comes to breeding, while for terns it is pretty much business as usual.
Turtle Doves are still very difficult to find but that might be more a sign of the times than a late arrival.
Turtle Dove by Jill Pakenham

It has been a reasonable spring so far for rarer migrants, the early part might be remembered for the influx of White-spotted Bluethroats, Subalpine Warblers and Woodchat Shrikes, whilst the Rock Thrush at Spurn will undoubtedly be a highlight for many. It is far from over yet though and the last half of May and first half of June can often host top-drawer rarities. We should also see the arrival of more of those late common migrants like Spotted Flycatcher, Nightjar and hopefully Turtle Dove.
So what does the weather promise this weekend? The forecast is for the weather to remain unsettled for at least the next few days but the winds will, at least on Sunday, have an easterly element in them, originating from Scandinavia.  Birds trying to head north through Northern Europe might get pushed west into the UK so there is a possibility of Red-backed Shrikes, Wryneck and possibly the odd Marsh Warbler.

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