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, 30 July 2015

Look to the sea

The conditions during the last few days have meant that any early passerine migration has been somewhat supressed. However, there has been a steady movement of seabirds offshore. Terns have started to head south, mostly Common and Arctic but also a good smattering of Black Terns too. The forecast unsettled weather should see more seabirds passing close to the coast. When terns are on the move skuas are not too far behind, so we should see more Great Skua, a few Arctic and the odd Pomarine being logged in the next week.

Pomarine Skua by Joe Pender

Scoters have also begun to move, mostly Common but one or two Velvets have also been seen. The highlight has probably been the movement of shearwaters. The southwest has enjoyed a few Great and Cory’s, whilst Manx Shearwaters have been moving down both the west and east coasts, and a few Balearics have been seen from the south coast.

Wader passage has begun in earnest, with passage migrants joining our breeding waders and the relatively small numbers of non-breeding species like Bar-tailed Godwit that over-summer on our estuaries.  For most wader species, it is failed breeders and adult males that leave the breeding grounds first, so these make up the majority of individuals here in July. Small numbers of adult Curlew Sandpiper, many still in their fine breeding plumage, and Little Stint are among the non-breeding waders logged in the last week. Moving into August, females and then juveniles will form a growing proportion of the waders passing through.

Post-breeding dispersal is well underway too, with mixed flocks of tits and warblers – including lots of juveniles – roaming the countryside. Although many of these will be locally-bred birds, migrants from elsewhere do pass through as well. Keep a look out for species like Sedge and Reed Warbler appearing in hedgerows and other ‘out of place’ habitats: a sign they may be individuals from further afield.

Finally – and even though it isn’t even August yet – five BTO-tagged Cuckoos are already in Africa!

Friday, 24 July 2015

Waders are go!

Waders are definitely on the move, or at least northerly breeding adults are. Numbers are beginning to build for a few species. Small flocks of moulting Spotted Redshank are being seen at several sites around the country, Green and Common Sandpipers are being recorded from many inland sites and the number of Dunlin, Knot, both Godwits, Whimbrel and Grey and Golden Plover are growing steadily in the Wash.
Spotted Redshank by Mike Weston

One or two Crossbills are still moving over coastal watchpoints, Swifts are still on the move but numbers seem to have stalled a little, however, those that are moving have been joined by small numbers of Swallows and Sand Martins, and the first Wheatears of the autumn are also turning up.
Great and Cory’s Shearwaters have been moving through the southwest approaches in small numbers and the first of the season’s Wilson’s Petrel can’t be far behind. Small numbers of Balearic Shearwater have been seen off Portland Bill.

Great Shearwater by Joe Pender

With all the wader activity it is hardly surprising that the odd rarity has been found, arguably the best of which is the Least Sandpiper that was found on St Agnes, Isles of Scilly, followed by the Broad-billed Sandpiper at Snettisham, Norfolk.

The weather forecast for the weekend looks promising for one or two more American waders to turn up. A fast-tracking low pressure system will arrive on the west coast of Britain on Saturday evening/Sunday morning. More White-rumped Sandpipers and the first Buff-breasted Sandpiper has to be on the cards. The southwest could also see more shearwaters and the odd Sabine’s Gull

Sabine's Gull by Joe Pender

Friday, 10 July 2015

Migration under way already

The small but steady trickle of Crossbills down the east coast of Britain is a sure sign that autumn migration has begun. Small flocks have also been popping up on the northern isles. Swifts are also on the move, an impressive 3088 were counted passing through Spurn, East Yorks, on 4 July, with 2845 through the same site a couple of days earlier.

Crossbill by

The BTO Cuckoos are on their way. We are currently following 18 birds as they make their way south. All of them have now left the UK, the last, David from Tregaron, Wales, left during the evening of 9 July. On the same day the first of them, Dudley, reached Africa. He is currently in southern Algeria. You can follow all of them here.

Cuckoo by Edmund Fellowes

Waders are also on the move, Common Sandpipers have started to turn up in southern locations, along with a few Greenshank, Spotted Redshank and Curlew Sandpipers. Inevitably a few rarer waders have turned up too. Pride of place has to go to the Terek Sandpiper that was found in Northumberland. Tresco, Isles of Scilly, played host to an American Golden Plover, and a White-rumped Sandpiper was found at Beacon Ponds, East Yorks.

Terek Sandpiper by Andy Mason

Surprise of the week has to be the touring flock of 10 Bee-eaters that have settled in Suffolk for the last few days.

According to the weather forecast, next week is likely to be more unsettled than the last couple of week, with most of the weather coming from the west. This shouldn’t stop the wader movement though and we should see a few more of these global travellers passing through. With the direction of the winds, maybe a Stilt Sandpiper will be found somewhere but even if not, I am sure there will be one or two unusual waders found somewhere.

Friday, 22 May 2015

Migration slowing down – or is it?

The weather has been such a mixed bag during the last couple of weeks it has been difficult to disentangle and work out what effect it has had on migrant birds. The almost autumn-like westerly fronts that have been tracking across the Atlantic do seem to have brought some Nearctic birds with them – Great Blue Heron, Hudsonian Godwit and Dark-eyed Junco are all incredible spring birds.

As the fronts have passed over Britain they have introduced sporadic southerly and south-easterly airflow, which at times has been quite productive. Spring 2015 will go down as a ‘southern herons’ spring, particularly in the south-west. If you were on the Isles of Scilly last week it was possible to see up to five Night Herons, two Little Bitterns, a Squacco Heron and a Purple Heron! It must have felt a little like being in southern Europe.

Squacco Heron by Derek Belsey

So, migration has continued apace but there are signs that it is slowing down; counts at coastal watchpoints are returning diminishing numbers. However, it does seem like some of the common migrants are still a little thin on the ground and that there are still plenty more to arrive. Perhaps we are in need of some warm southerly winds to test this out. Certainly here in East Anglia there seems to be fewer Cuckoos than were around last year and the BirdTrack reporting rate seems to reflect this nationally. Willow Warbler and Whitethroat are showing similar reporting rates, and if Spotted Flycatcher is to get anywhere near the BirdTrack historical reporting rate there are a lot more to arrive yet.

BirdTrack reporting rate for Cuckoo

Skuas have been on the move past the Outer Hebrides during the last couple of weeks; the highest count has been of 1,307 Long-tailed Skuas flying past  Aird an Runair, North Uist on 12 May, and accompanied by 353 Pomarine Skuas must have been an amazing sight.

Pomarine Skua by Joe Pender

Quail have begun to turn-up in small numbers. These enigmatic little birds can be quite common in some years and almost absent in others. As Quail can still turn up in early June, it is still a little too early to tell whether this will be a Quail year, or not.

So, what might we expect this weekend? Initially it looks like we will have light northerly winds at least on Saturday into Sunday morning, and again on Monday. At this time of the year these conditions can be quite productive. Migrants birds can and do migrate into light northerlies and if there is going to be a late push, Saturday and Sunday morning look good. On the rarity front, something from the south east is always on the cards this late in May – Red-footed Falcon is the obvious candidate but a spring male White-throated Robin would really set pulses racing.

Friday, 24 April 2015

Migration in full swing – almost

Migrants have been piling in during the last week – Willow Warbler counts have reached three figures on several days at south coast watchpoints, there have been small flocks of Ring Ouzels on the east coast and Cuckoos have reached Scotland but it still feels like many of our summer visitors are still thin on the ground. Where are all the Sand Martins? And there really ought to be more Lesser Whitethroats than there are. The next week or so should unveil whether some birds are just held up further south or whether they had a bad winter.

BirdTrack reporting rate for Sand Martin

Even though some species feel a little low in numbers most species are now here. There have been one or two Nightjars during the week, Swift numbers have been steadily growing, a flock of fifty birds were counted at Longham Lakes, Dorset, earlier in the week, and the first Spotted Flycatchers have also arrived.

Great Spotted Cuckoo by Cliff Woodhead

Southern overshoots have been well represented, mostly by the Hoopoe; there could have been between fifty and one hundred in the country.  It is difficult to know how many Black-winged Stilts turned up, eight were seen together in Kent, with several ones and twos later in the week that could have been some of these birds dispersing, or different birds altogether. A Great Spotted Cuckoo was found in Wales, and at least six Bee-eaters graced southern counties for a few days. Given the easterly airflow there were few birds from that direction, almost certainly because the winds actually originated out in the Atlantic north of Britain and came down through the North Sea and into the east coast and not from the continent.

Purple Heron by Northeast

The forecast for the next week is a little more unsettled than the last week, with westerly winds dominating all week. At times these will be quite light and during these periods birds will arrive. So, it will be more of the same although Ring Ouzel numbers will definitely be much lower. The last week of April is often marked by the mass arrival of Swifts and looking at the forecast there doesn’t seem to be much that will hold them up, so look out for them in the next few days. More of the BTO Cuckoos ought to make the last leg of their journey and, fingers crossed, Chris the Cuckoo (tagged in 2011) will arrive back. You can follow the Cuckoos here as they complete their journeys. As far as rarities go, I’m hoping for a Purple Heron, or Little Bittern on my local patch.

Thursday, 16 April 2015

What an amazing week

The weather conditions finally changed for the better, allowing migrants birds that were held-up further south to begin making their way north again, and they did! Ring Ouzel lead the way with over 500 birds being reported from the south coast to Northumberland.

Grasshopper Warbler by Amy Lewis

Willow Warblers piled in, over 300 arrived at Hengistbury Head, Dorset, on the 13th. Portland, also in Dorset, counted 500 on the same day. A few Sedge, Reed and Grasshopper Warblers arrived, along with a small number of Whitethroat and Lesser WhitethroatSwallows and House Martins are also back in good numbers and a few Swifts have also been seen.  Yellow Wagtails and Tree Pipits, Redstarts and Pied Flycatchers arrived bang on cue but although Blackcaps are now around in good numbers the main arrival is around a week later than the norm.

Pied Flycatcher by Edmund Fellowes

One of our latest summer migrants to arrive back is the Nightjar, sometimes the first birds are not seen until early May, so, one flushed from the car park at Dungeness, Kent on 12 April is very early. The first Nightingales have already taken up territories in some areas and are in full song and Cuckoos have been heard as far northern England. Four of the BTO satellite tagged Cuckoos are now back in Europe, one is in south west France and the other three birds are in southern Spain. Follow them as they make their way back to the UK here.

The warm southerly airflow that opened the floodgates also brought a number of Mediterranean overshoots with it, most notably Hoopoes, just under a hundred have been reported, mostly from southern counties, with at least eighteen present on the Isle of Scilly alone. At least three birds reached Scotland.  Wrynecks were also well represented, with at least thirty birds found. A couple of Woodchat Shrikes, Alpine Swifts and single Great Spotted Cuckoo, Scops Owl and Bluethroat, all added to the continental flavour but all of these were eclipsed by Britain’s second ever Great Blue Heron, found at the exact location of Britain’s first; Lower Moors, St Mary’s, Isles of Scilly, eight years earlier.

Bluethroat by Edmund Fellowes

So, what can we expect during the next week?

High pressure and relatively light easterly winds are forecast for most of next week which should allow more migrants to move and we should see the number of many of our common summer visitors grow. On the rarity/scarcity front we might see a slightly different mix bringing a bit of an eastern flavour with it. Red-footed Falcon, one or two more Bluethroats and a Pallid Harrier or two could be on the cards.

Thursday, 2 April 2015

Migration gets underway again

The strong north westerly winds brought migration to a halt prompting the migration stalwarts at Christchurch Harbour, Dorset to comment on their daily log for the 31 March, there were no incoming migrants today. However, as we go into the Easter weekend it looks like all that could be about to change; the wind has been dropping all the time over the last couple of days and migrants have responded accordingly. The first Sedge and Reed Warblers Warblers were seen, Swallows have begun to arrive in reasonable numbers and there have been a few more reports of House Martin and Sand Martin too.

Sedge Warbler by Dawn Balmer

Willow Warblers are also starting to appear and the first two Whitethroats of the spring have also been seen.  With the warmer weather starting to arrive, Osprey reports are also picking up across the UK. Today, 10 birds were seen, signalling that spring is definitely here. Most of these reports were noted as flyovers, from 14 different counties, ranging from Sussex, through Staffordshire and as far north as Co. Durham and Cumbria.

Osprey by

With the weather forecast to settle over the weekend, the floodgates could really open with Sunday possibly being the best day to go in search of summer visitors.

A Night Heron, on St Mary’s, Isles of Scilly might just be the forerunner for one or two more overshooting Mediterranean birds too. Following on from the Alpine Swift in Sussex earlier in the week my bet, albeit tentatively, is on Red-rumped Swallow. 

Red-rumped Swallow