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.

Thursday, 17 April 2014

Spring migration steps up a gear

I have spent the last week on the Kent-Sussex border under blue skies, enjoying wall-to-wall sunshine and warm temperatures – not the best weather to experience any visible migration. On a one hour sample vis-mig watch at Dungeness on Monday morning I managed two Swallows, a Wheatear, a single Yellow Wagtail and a Pied Flycatcher that came in off the sea. 

There was a little more action over the sea. Common Scoter proved to be the most numerous migrating bird, in all twenty-seven flew west up the Channel during my sample hour, along with eight Gannets, two Red-throated Divers, nine Brent Geese and seven Whimbrel.

 Gannets by Jill Pakenham

It has definitely been quiet on the coast – the weather has just been too good and as a consequence any active diurnal migration will be happening high in the sky, out of earshot and eyesight. This is borne out by the number of summer migrants that have gone straight in land and are already on their breeding grounds. Pied Flycatchers and Redstarts are already singing in Welsh woodlands, a Nightingale was trapped during the week at its Cambridgeshire site and a few Cuckoos have been heard singing as far north as Northumberland, which bodes well for the BTO satellite tagged birds. We have three Cuckoos in Spain, with Skinner being the furthest north and Waller and Chris just a little further south. Any could make it back here during the next week. You can follow them as they complete the final leg of their mammoth journey here.

The mainly light northerly winds of the last week have been ideal for overshooting Mediterranean birds and we haven’t been disappointed. Star of the show was a Crag Martin in Yorkshire, however, three Hoopoes together in Devon and a flock of ten Black-winged Stilts on the Isle of Wight must take close second.  Red-rumped Swallow in Norfolk, White-spotted Bluethroat in Herefordshire and a Serin on the Outer Hebrides, A Tawny Pipit in Yorkshire, and two Bee Eaters on Scilly made for a good supporting cast. 

Of interest, we received evidence of outward migration across the North Sea in an email to the BTO. See below:

This bird landed on our cruise ship as it was near Shetland (heading towards Norway), but the weather was too stormy to dock there, so presumably the bird needed a bit of a rest.  

Skylark by Maureen Taylor

If the week belonged to any one species though it must belong to Ring Ouzel, a search on Birdguides returned one hundred and seventy-nine reports of birds from Scilly to Lancashire. So, what can we expect for the coming week.  Mid-April-mid May is the peak time for spring migration and we can expect almost anything to turn up. However, the best of it will always coincide with east/south-easterly airflow. This coming Sunday morning could be one of the best days of the spring so far to experience visible migration. The forecast is for a murky start, with the strong possibility of light rain, which will either bring moving birds lower or ground them altogether. Whimbrel will probably be the most obvious migrant next week but Reed and Sedge Warblers ought to also pile in, and by the end of the week many of us should also see a few Swifts. 

Ring Ouzel by Tommy Holden

On the scarcity/rarity front, with east/south-easterly wind forecast for the early/middle of the week we could be in for a treat with an eastern flavour. White-winged Lark is well overdue, as is Rufous Bush-Chat. We can but dream.

Thursday, 10 April 2014

Still not exactly flooding in

The spring migration momentum has picked up quite a bit this week with Swallows, Blackcaps and Willow Warblers leading the way. However, birds haven’t exactly been pouring in. With high-pressure extending all the way from Spain to southern Britain, the conditions looked ideal for birds that were being held-up further south to make their move, and of course those that were already well on their way did, resulting in a fresh arrival of Grasshopper Warblers, Redstarts, Pied Flycatchers and the first few Common Sandpipers and Lesser Whitethroats, the numbers were on the relatively low side though considering the weather conditions. It seems that birds might have been held-up much further south by strong north-westerlies in southern Spain/North Africa.

Redstart by John Harding

The conditions did, however, bring in the predicted Black Kite; a bird flew along the North Norfolk coast on 9 April, being seen at several sites on the way. Three Red-rumped Swallows also overshot this week.

Black Kite by Luke Delve

Britain is going to be blessed with high-pressure again next week but the wind is largely going to be from the north/north-west and could be pretty stiff at time. There will be periods of very light northerlies though and, at this time of the year these conditions can result in some of the largest arrivals – it seems that migrating birds are more in control flying into a headwind than with a tailwind. It is going to be a game of two halves though – whilst southern Britain enjoys light winds, warm temperatures and reasonably dry conditions, northern Britain will be experiencing strong westerly winds, relatively cool temperatures and, at times, heavy rain.

Whitethroat by Amy Lewis

So, what might we expect? For south coast visible migration watchers, Saturday looks like the day to be out and about. A weak front is forecast to move south overnight on Friday and could produce murky conditions for a brief period, possibly grounding any migrants that left northern France in much better conditions. This could also be repeated on Sunday into Monday and again Wednesday into Thursday.  In between, when the conditions are a little more settled, we might just see the floodgates finally open and enjoy a variable host of long-distance migrants. Whitethroat could be the most obvious arrival, along with Sedge Warbler and House Martin, and as for scarce migrants, Purple Heron is my prediction.

Friday, 4 April 2014

Floodgates still to open

Whilst there has been a lot more migration action during the last week, the floodgates are still to open. That said, Chiffchaff and Blackcap numbers definitely increased markedly this week and the first flush of Willow Warblers also occurred pretty much on cue, and neatly illustrated by the BirdTrack graph below.

BirdTrack reporting rate for Willow Warbler

A few more Redstarts, Grasshopper, Sedge and Reed Warblers were seen, along with the first Pied Flycatcher and Tree Pipit. There have been a few more reports of Cuckoo, none of them concerning any of the BTO satellite tagged birds, the first of which is crossing the Sahara as I write and is currently just south of the border between Mali and Algeria. By this evening, if all goes well, he should have completed what must be the most arduous part of the migration back to the UK. You can follow his and the other birds journeys here.

Pied Flycatcher by Edmund Fellowes

Departing winter visitors are still a feature, with flocks Redwing, and in particular, Fieldfare, occurring in good numbers. A flock of 150 Fieldfares were on my local patch at Lakenheath mid-week. So, now is a good time to get out and help the BTO chart the thrush departure as part of the Winter Thrushes Survey. The survey closes in mid-April. Another local feature this week was a small flock of around a dozen or so Brambling in a small beech wood in Thetford Forest in full song.

As predicted, inland waterbodies were well worth checking this week, Common and Velvet Scoter - sometimes in small flocks - being found at several sites. A Blue-winged Teal was found in Northamptonshire, but pride of place has to go to the Baikal Teal found in Cambridgeshire. Whether it is a genuine vagrant might be open to debate but the timing is good and another drake was found in Belgium this week. Whatever the final decision is won’t detract from the stunning beauty of the bird.

Baikal Teal by Dave Key -

On the scarcities front, another Great Spotted Cuckoo was found in Devon, and a handful of new Hoopoes also arrived.

So, what might we expect this week? Things are likely to continue in the same vein for the first part of the week, however, high-pressure is forecast to build over southern Europe around mid-week bringing very light south-westerly winds from North Africa to northern France. Anything that has been held up in poor weather and strong winds over the last few days in northern Spain/southern France, will begin to move north and we might finally see the floodgates open. Southern overshoots are also definitely on the cards from Tuesday onwards. Black Kite and Woodchat Shrike are my guess.

Friday, 28 March 2014

The floodgates could open this weekend

With a warm south-easterly airflow forecast for the next few days, the scene is set for a rush of long-distance migrants to arrive. Chiffchaffs have trickled in steadily during the last week but this weekend should see the floodgates open.  Along with Chiffchaffs we should see a rush of Blackcaps, Sand Martins, Swallows and Ring Ouzels.

Blackcap by Adrian Dancy

The BTO satellite tagged Cuckoos are still in West Africa but will be getting ready to cross the Sahara any day now. Chris the Cuckoo was the first to do this on 4 April last year. So, of the eleven birds that we are following any one of them could move any day now. Check them out here. Knowing this, it came as a surprise when the vis mig watchers at Hengistbury Head, Dorset, saw a Cuckoo coming in off the sea on 27 March. Maybe there will be more during the next week taking advantage of the forecast weather.

Cuckoo by Steve Ashton

Although a good variety of species of summer migrants have already been recorded this spring, we should see this increase rapidly during the next week and there could well be some interesting birds too. It is still a little early but I wouldn’t be too surprised if the odd Bluethroat was found and, even though it is not traditionally a spring bird, Rustic Bunting is not unprecedented at this time of the year, bearing in mind the forecast conditions.

Bluethroat by Amy Lewis

Any lingering winter visitors should also clear out during the next week, so we could see odd flocks of Redwing, Fieldfare and ducks, geese and swans on the move too. It could be well worth checking out those inland lakes, gravel pits and reservoirs for a scoter or two.

Friday, 14 March 2014

Spring has arrived!

The high pressure system over the UK during the last few days brought the forecast spring-like conditions, and the expected rush of long-distance summer migrants. Wheatears made it as far north as Mull, Argyll, and the first House Martins joined Sand Martins and Swallows but it was a reeling Grasshopper Warbler and a couple of Yellow Wagtails that were most surprising amongst the common migrants. The average arrival date for the former is 13 April and 7 April for the latter, according to BirdFacts.
Yellow Wagtail by Jill Pakenham
Chiffchaff numbers began to build, bang on cue, and Meadow Pipits were on the move too, 330 were counted during a visible migration watch on Hengistbury Head, Dorset on 12 March, with four figure totals for Portland, also in Dorset on the same day. Smaller numbers of ‘alba’ wagtails also featured at both sites. The first Ring Ouzels were seen, along with a few Little Ringed Plovers and, as predicted, overshooting Hoopoes arrived, at least six were found, all in the south-west, with the exception of one in Kent also arrived in perfect overshoot conditions, which also brought a Great Spotted Cuckoo and a Wryneck to Pembrokeshire.

Great Spotted Cuckoo by Cliff Woodhead
Redwings have featured as a species on the move at several migration watchpoints, along with small flocks of Pink-footed Geese and Whooper Swans – twenty-five of the latter were seen sitting on the sea off Flamborough Head on the 12th, with another twelve past there on the 13th .
Whooper Swans by Jill Pakenham
High pressure is still set to dominate over the next few days with light north-westerly airflow setting in. This may well slow things down a little but won’t stop migration altogether, so, things are set to continue in a similar vein. Saturday into Sunday looks best for any overshooting migrants with Hoopoe still being favourite, and we could see the first large movement of Meadow Pipits and White Wagtails, and perhaps a few more Ring Ouzels.  

Friday, 7 March 2014

Get ready for an arrival of Chiffchaff

The last week has been fairly quiet migration wise, largely as a result of a fairly stiff westerly airflow, and the fact that it is still quite early in the season. However, a few summer visitors did manage to find their way here. At least four Ospreys were seen during the week, all in southern counties, and at least two more Garganey joined the couple that were here from the week before, along with a handful of Sand Martins.

Osprey by Luke Delve

With high pressure forecast to and warm southerly air forecast for Saturday we could see the first noticeable push of migrants into the UK and Chiffchaff has to be the favourite species to lead the way. At present we are in week ten of the year and the BirdTrack historical reporting rate shows that Chiffchaff begins to rise rapidly from week 11 (see below), so the timing couldn’t be better. 

ChiffChaff reported to week 10 (blue), historical (red)

The warm sunny and relatively still conditions are forecast to run well into next week too and, with high pressure stretching all the way from North Africa to northern Britain, we could see the odd Mediterranean overshoot. It is a little early but Hoopoe and Alpine Swift could be on the cards.

Migrants leaving the UK will also be able to take advantage of the light winds and good conditions and we should see an exodus of many of our winter visitors over the next few days. A migration watchpoint will definitely be the place to be over the next few days.

March is also the month when gulls are on the move and this was in evidence at Christchurch Harbour yesterday (6 March) when two Iceland Gulls, a Glaucous Gull, thirty-four Mediterranean Gulls, two Little Gulls and 98 Common Gulls were counted moving west past the site.

Mediterranean Gull by Andy Mason

Pelagic Birder who is currently off the coast of Ghana is reporting a large movement of skuas, mainly Pomarine but also involving Arctic and Long-tailed and a good numbers of Black Tern.

Friday, 28 February 2014

Spring might be back on hold

The short spell of warm southerly airflow that we experienced last week did bring a small number of summer migrants to the UK. A handful of Sand Martins were seen at a couple of south coast locations, a Swallow was seen in Somerset, a pair of Garganey were seen in Buckinghamshire and a Great Spotted Cuckoo got as far north as Ouessant, Brittany There was also some evidence of a small arrival of Chiffchaff on the south coast.

Garganey by Dawn Balmer

The return to, at times, strong westerlies put paid to further arrivals from the south this week but it didn’t stop some of our departing migrants from moving. Small numbers of Pink-footed Geese have been seen moving north along the east coast, and Greylag Geese have also been seen on passage over Fair Isle.

There has also been some auk passage past west coast watchpoints, mostly involving Guillemots and to a lesser extent, Razorbills. There have also been a few Puffins on the move but it seems that a large number of Puffins were caught up in the severe storms that lashed the Bay of Biscay last week. A coordinated count of dead Puffins on the beaches of France, between Finistère to the Spanish border, found over 12,000 individuals, amongst over 21,000 seabirds. Most of these birds would be just about to start the return journey to their breeding colonies, Ringed birds recovered so far have come from colonies in west Wales, northern Scotland, Orkney and Shetland.

From much further south, we received a report of Pomarine and Arctic Skuas on the move, along with a small number of Grey Phalaropes, in fact these birds were observed on passage from a research vessel 20 nautical miles off the coast of Ghana. With a bit of luck these birds could be flying past a British headland in a month or so. See here for more.

Pomarine Skua by Joe Pender

One of our satellite tagged Cuckoos has begun the second leg of his return journey to the UK and is now in Ghana, just north of Lake Volta. It won’t be too long before some of the others join him there.

The weather forecast for this weekend doesn’t look too promising for much migration to take place, however, there will be a small window during Saturday afternoon and Sunday morning when the winds in southern Britain will be light and from the south, courtesy of high pressure over France. If there are any migrants holding-up in France, Sunday morning might see them arrive here. It is still very early though so it would only involve a small number of birds. Wheatear has to be favourite with perhaps the first flush of Chiffchaffs.