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.

Friday, 10 May 2013

Skuas are go!


With the onset of strong westerly winds, passerine migration has slowed a little. But these wind have pushed migrating Pomarine and Arctic Skuas closer to shore, with some birds moving through the English Channel, with the weather forecast to remain unsettled for the next three or four days, seawatching might be the order of the day.
Arctic and Pomarine Skua by Martin Cade

After the initial flush of Hobbies the last week has seen many more arrive, and although they are still running a little late they are beginning to catch up. The same can’t be said for Spotted Flycatcher and we still await their main arrival.

BirdTrack reporting rate for Hobby


Swifts have moved back onto breeding sites and can now be seen over many towns and cities, although they are present in smaller numbers than is usual. With strong westerly winds forecast for the next three or four days we might have to wait for their numbers to build up.

BirdTrack reporting rate for Swift



Common summer migrants have continued to pass through coastal watchpoints, with Whinchat being one of the most noticeable, along with further arrivals of Blackcap and Garden Warbler. With a spell of south-easterly wind mid-week rare and scarce birds were well represented, the pick of which for many will be the male Collared Flycatcher that was found in Northumberland. The same county also hosted a Black Stork!

Whinchat by Edmund Fellowes

Up to ten Hoopoes were seen from Scilly to the Outer Hebrides, a flock of eight Bee-eaters made a brief appearance in Norfolk and up to four Red-rumped Swallows were seen. Whilst from further east, Thrush Nightingale and Icterine Warbler were both seen on Fair Isle, and a male Red-breasted Flycatcher on nearby Mainland Shetland.

So, with strong westerlies the norm for the first part of next week things might be a little slower than last week but Skua migration could be very impressive. From mid-week the forecast is for more south-easterlies and maybe a repeat of last week’s birds and the possibility of a mega-rare. A full breeding plumaged Caspian Plover would see many birders heading to wherever it makes landfall.

Friday, 3 May 2013

Migration continuing apace


The first few days of May can be a turning point in spring migration as numbers of those species that are already represented build towards the full complement, as if to prove this Blackcap, Whitethroat, Garden Warbler ,Willow Warbler and Nightingale have all arrived in force during the last week.

BirdTrack Blackcap reporting rate


This is also the classic arrival time for Swift, and bang on cue, Swifts rapidly spread across the country over the weekend, along with the first few Turtle Doves.

Turtle Dove by Mike Weston

 Two of the BTOsatellite tagged Cuckoos are back on their breeding grounds on the shores of Loch Katrine, Stirlingshire, and House Martins have been recorded back at their nests too. If you have House Martins we would really like to hear about them via the BTO House Martin Survey.

It has also been a week of classic Mediterranean overshoots, with up to seven Purple Herons scattered around the country, a Bee-eater in Shropshire, at least six Hoopoes spread from Cornwall to Ayrshire, five Red-rumped Swallows and a flush of Golden Orioles adding to the flavour.The last few days have also seen a mini-influx of Red-footed Falcons, with as many as five birds arriving, at least four in the East Anglian Fens and one on St Martin’s, Isles of Scilly.

Collared Pratincole by Dawn Balmer

So, what can we look forward to this weekend? With very light winds forecast for much of southern Britain, as a result of high pressure that will extend all the way down to Spain, and by Monday, North Africa, we can look forward to more of the same, in southern Britain at least. It seems that the north is returning to wintry conditions which will put a temporary hold on things there, and as it’s May, we could just about expect anything to turn up. Collared Pratincole would
be my favourite.

Friday, 26 April 2013

The migration floodgates open


Migration stepped up a gear this week on all fronts. Common migrants arrived in many parts of the UK and, in good numbers for the first time this spring. Reed and Sedge Warblers were recorded back on their breeding territories, Whitethroat numbers began to build up and a few more cuckoos were heard. Check out the BTO website for some exciting Cuckoo news.

Spotted Flycatcher by Ron Marshall

Swifts traditionally arrive en-masse during the last few days of April and the first few days of May. With the number of reports growing through the week it looks like they could be true to form. Spotted Flycatcher is also has a late April arrival and as if to prove a point Portland Bill, Dorset, enjoyed their first birds this morning.

Short-toed Lark by Ron Marshall

Black Terns have also been moving through the country in small numbers but it is the scarce and rare migrants that have stolen the show this week. At least four Subalpine Warblers, ten Woodchat Shrikes, ten Serins and eight Hoopoes were found, along with a couple of Short-toed Larks, five Red-rumped Swallows, two Citrine Wagtails and three singing Iberian Chiffchaffs. Star of the show has to be the female Rufous-tailed Rock Thrush that was found at Spurn, East Yorkshire on 25 April.

Our winter visitors also managed to get away as shown by the BirdTrack graphs below.




Alpine Accentor by John Harding
The weather forecast for this weekend promises to slow things down a little. However, very light winds across most of France and southern Britain on Sunday could hold some promise.  As southerly overshoots are the order of the day an Alpine Accentor would be nice.

Friday, 19 April 2013

Migration getting back to normal


For some at least. The last week has seen a wide range of summer visitors arrive bringing them to the levels we would expect at this time in the spring. House Martin, Sand Martin and Swallow have all pretty much caught up after a very slow start.





For our early warblers it is a very different picture though. Chiffchaff, Willow Warbler and Blackcap are all running about two weeks behind.





Mid-April to mid-May is the peak time for spring migration and it is already showing signs of hotting up. Pied Flycatchers and Redstarts are back in reasonable numbers. Our mid-spring arriving warblers are already showing their presence with Grasshopper Warbler, Whitethroat and Reed and Sedge Warbler being widely reported. The first flush of Yellow Wagtail are moving through, and the first Swifts of the year have also been seen, with one making it as far north as Fair Isle to become the earliest ever island and Shetland record.

Grasshopper Warbler by Amy Lewis

Further north migration is still slow as two of my colleagues add - Jenny Gill and Graham Appleton are reporting that migration into Iceland is very slow this year.  They are particularly looking for colour-ringed Black-tailed Godwits, the arrival of which they record every year, but numbers of Redshank, Snipe and other birds that winter in the UK are also unusually low.  Has the weather prevented the godwits from taking off from passage sites in Britain, Ireland & the Netherlands, have they stopped in northern Britain prior to the sea crossing, or could they have died en route across the Atlantic.  If you encounter any of these colour-ringed godwits please send sightings to j.gill@uea.ac.uk
While they wait for the godwits though, they are enjoying wonderful views of sea eagles and Gyrfalcon!

Red-rumped Swallow by Kris Webb (Scilly Spider)

Strong gale-force winds have dominated the weather this week and have no doubt slowed down migration – birds don’t generally like flying too far in strong winds. However, the winds are beginning to drop and on Sunday there will be light northerlies extending all the way from Northern France to central Spain. Migrant birds like to fly into light northerlies and I have seen some of my largest spring arrivals on the south coast of Britain during light northerly winds. So, Sunday looks like a classic Alpine Swift/Red-rumped Swallow and Hoopoe day.

Paul Stancliffe 

Wednesday, 10 April 2013

Summer migrants set to arrive in force


Migrants have continued to trickle in during the last week but it has been slow. Most of our early arriving summer visitors are running two to three weeks behind, as can be seen in the BirdTrack reporting rate graphs for Chiffchaff , Sand Martin, Willow Warbler and Swallow. However, with a change in the weather other species have arrived bang on cue.



Whitethroat, Sedge Warbler, Reed Warbler and Grasshopper Warbler all have an average arrival date around mid-April and all have been seen in the last few days. Large numbers of visible migrants have also been seen, largely comprising Meadow Pipit and Woodpigeon, 5000 of the former and 2000 of the latter were counted flying over Portland, Dorset on 9 April.

Despite the cold conditions and strong easterly winds, BirdTrack shows that the arrival of Ring Ouzel has been spot-on.  Conversely, it may come as no surprise that the classic winter thrushes, Redwing and Fieldfare, are late leaving.


Fieldfare by Edmund Fellowes

The average arrival date for Whinchat is the 17 April. We aren't aware of any in the country yet but we expect the first arrivals next week. We still need more help to monitor this species in Wales. Could you help with the second year of the Welsh Chat Survey?


Whinchat by Edmund Fellowes

Two more Cuckoos were reported this week, in East Sussex and Kent, and our first satellite tagged Cuckoo won’t be far behind. Chris is currently in southern central France but he could make his move for the UK any day now- read his blog here.

Woodchat Shrike by Ron Marshall

We should finally see the back of the cold easterly airflow this weekend and the forecast is looking good for southern migrants. By Saturday we should be enjoying warm winds from the south which will bring migrants that have been held up with them. This weekend has the potential to be one of the most exciting of the spring. Summer migrants will be able to make their final dash to their breeding grounds, and winter visitors may finally get an easy passage across the North Sea. With the winds coming from so far south I wouldn’t be surprised if the two Hoopoes reported in the last couple of days aren’t joined by more Mediterranean birds. Woodchat Shrike is always a favourite at this time of the year.

Thursday, 4 April 2013

Migration still slow

By now the scene is normally set for the arrival of our summer visitors, the buds have normally burst on early leafing trees such as willow and Birch, and caterpillars have hatched to take advantage of the young spring leaves. Yesterday morning (Wednesday 3 April) I took a walk through the wood on Hengistbury Head, Dorset, an old local patch of mine, in the hopeful search of summer migrants. It looked and felt like it did when I walked there at the end of December, leafless trees and the biting cold giving not a hint of early April. The scene was the same in the double dykes area of the headland, a willow filled ditch that would normally, at this time of the year, provide tired Chiffchaffs andWillow Warblers with a good supply of insect food - right now they are leafless, insectless and without warblers.

Summer migrants are arriving though, and I did manage my first of the year, three male Wheatears and a lone Sandwich Tern. Warblers and hirundines were sadly lacking though, by now the Sand Martin colony the eastern end of the head would normally be occupied. Presumably the martins that arrived in early March have struggled to survive. We have been given a hint of this struggle. Over the last few days there has been an arrival of Chiffchaffs, particularly in the south-west. In the desperate struggle to find food these birds are searching in the grasses and along the tideline, and around the feet of their observers.




One of 15 Chiffchaffs feeding on flies on Wembury Beach, Plymouth.

Photos by Brian Nixon 

Despite the conditions the first Cuckoo was reported in Devon on 31 March and it looks like the first of our satellite-tagged Cuckoos won't be too far behind, as Chris's tag transmitted from northern Algeria just this morning, indicating he had successfully crossed the Sahara Desert.  Follow his journey and that of the other four birds as they return to the UK at www.bto.org/cuckoos.

The first Yellow Wagtails have arrived, hinting at the backlog of migrants that are presumably held up in France and Spain. The forecast for the weekend could well be in their favour, particularly on Sunday, when light southerlies and slightly warmer temperatures are promised, at least in the south of the country. This could be the day that the floodgates open, and the day to be out vis migging.