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, 31 October 2014

Plenty of birds still to come

The last few days have seen a large movement of thrushes (mostly Fieldfares) and Starlings across the North Sea, prompted by high-pressure and resultant light winds from the east coast of Britain to the continent.

Fieldfare and Redwing by Anne Cotton

Falsterbo Bird Observatory in southern Sweden have also experienced a large movement of birds but of different species. Goldcrests. Long-tailed Tits and Robins have dominated there.

The weather forecast for the next week is for predominantly westerly airflow, strong at times as weather fronts cross the UK. However, in between these fronts the winds will become lighter and although not enough to allow Goldcrests to cross the North Sea, we should see further arrivals of thrushes and Starlings. There does seem to be a small window of light easterlies forecast for the middle part of next week and we could see a mass arrival of Goldcrests and Robins then, not to mention Short-eared Owls

Short-eared Owl by Amy Lewis

There is also a chance that we could see some frosts, and if the conditions are clear, with light easterly wind we could see what for me is the greatest autumn migration spectacle; large numbers of Wood Pigeons making their way south and west. This species is responsible for my own largest visible migration count, an almost continuous stream of around 50,000 birds migrating west over Hengistbury Head, Dorset.


If we do get the promised easterlies, we might see a Desert Wheatear on the east coast too.

Friday, 17 October 2014

Winter is here

Well, at least winter thrushes are. It finally happened during the early part of this week; Redwings seemed to be everywhere as they arrived in force, with flocks moving inland very quickly. Ring Ouzels also moved bang on cue, but in impressive numbers – over 500 were recorded at Dungeness, Kent on 14 October, and 150 were counted heading out to sea at Foreness, also in Kent. The BirdTrack graph shows just how bang on cue they were.

BirdTrack graph showing reporting rate for Ring Ouzel

Other birds on the move included Goldcrests and Robins but in much smaller numbers. Bramblings have also started to put in an appearance. We might have to wait a little longer for a large arrival of these, the weather for most of next week will put us firmly in a westerly airflow.

Goldcrest by Jill Pakenham

Things were much quieter on the rarity front, however, Britain’s seventh Audouin’s Gull was found at Dungeness, probably pushed north by the strong southerly airflow of last weekend.
The first big movement of Woodpigeons was recorded earlier in the week too; on the other side of the North Sea. Over 40,000 were counted migrating through Falsterbo, Sweden on the 14 October. Again, we will have to wait for clear conditions and some east in the wind before we see anything like that sort of movement here. The largest counts of Woodpigeons on the move here are often made during the first two weeks of November.

So, what might we expect nest week? The west and south-west ought to be the place to be, and we could well receive one or two American vagrants off the back of Hurricane Gonzalo, which is due to leave the North American seaboard on Sunday morning, arriving here, although having lost a lot of its energy, around lunchtime on Monday. As I am going to be on the Isles of Scilly next week I am hoping for anything from across the Atlantic, although I would love to see a Black-and-white Warbler. During quieter spells visible migration should pick-up again and we ought to see more Fieldfares in the mix of thrushes.

by Paul Stancliffe

Thursday, 9 October 2014

You know it's October when birds begin turning up from all points of the compass. The first real westerly storms of the autumn brought more North American birds with them, with the cream of the crop being a Scarlet Tanager on the Outer Hebrides. This is the eleventh to be found in Britain and Ireland. The second Swainson’s Thrush of the autumn was found on Loop Head, Clare, there was a Solitary Sandpiper in Wexford and a couple more Red-eyed Vireos made it across the Atlantic, one to Northumberland and one to Mayo.

As predicted, birds also arrived from the east. A Steppe Grey Shrike arrived in North Norfolk over the weekend, a Blyth’s Pipit was identified on the Isles of Scilly and the first 2 Radde’s Warblers of the autumn were found on Shetland, while a Little Crake graced Minsmere, Suffolk. At least four Rough-legged Buzzards were reported and the northern islands saw the largest arrival of Redwings, although we are still waiting for the main arrival of winter thrushes.

Song Thrushes, Robins, Starlings and Goldcrests have begun to move through coastal watchpoints on the Continent but the low pressure system that has been wheeling around off our west coast has largely blocked a crossing of the North Sea. However, the stormy conditions will abate over the weekend and there will be light south-westerly/westerly airflow across the North Sea, light enough to perhaps encourage a few birds to attempt a crossing.

Brambling by John Harding


So, we should see the first big movement of Starlings and thrushes. Bramblings should also feature in visible migration counts, and we could see the last flocks of Swallows and House Martins heading off. The latter species is of particular interest to the BTO; we have lost over half of our breeding House Martins during the last twenty-five years and whilst we know that they are faring better in Scotland and Northern Ireland than they are in England, we don’t really know why. Is it a loss of complete colonies or a general reduction in colony size and why are losses greater in certain parts of England compared to others. To help find this out we will be launching a special survey in 2015 & 2016 to gather further information. Find out more here.

House Martin by John W Walton

The early part of next week will see the next low pressure system cross the Atlantic, so birds from the west are on the cards once again, but just like this week as the front/fronts pass through we should see the arrival of birds from the east too. It is anyone’s guess what might turn up but Yellow-billed Cuckoo and Radde’s Warbler would fit the bill.

Friday, 3 October 2014

West meets east.

The westerly airflow produced the good in the shape of several North American landbirds this week. At least three Red-eyed Vireos were seen, a Swainson’s Thrush and Yellow-rumped Warbler graced Shetland and an Ovenbird put in a brief appearance in County Cork. It seems ironic that a week of mostly westerly airflow should also turn up some top-drawer eastern rarities too. An obliging White’s Thrush was found in a garden on Mainland Shetland, a stunning male Eyebrowed Thrush graced the North Ronaldsay Observatory Garden in Orkney, with a Pechora Pipit being seen over the Obs garden on the same day.

Ovenbird by Bryan Thomas


Whilst westerly airflow spanned pretty much right across the North Atlantic for the latter part of the week, a low pressure system was creating north westerly airflow out of central Russia, which made landfall in Scandinavia, which could the almost simultaneous arrival of the White’s Thrush and Yellow-rumped Warbler around four miles apart on Shetland.

Skylark movement got underway this week, 119 were counted over Spurn, East Yorkshire on 2nd October, with Bardsey, Gwynedd, counting 205 over on the same day. Chaffinches are also starting to feature in visible migration counts too, although it could be a couple of more weeks or so before they really get moving.

The 2nd of October also saw a record 45,800 Pink-footed Geese arrive at Martin Mere, Lancashire, much smaller numbers have been seen moving south on the east coast of Britain, however, the east coast has seen a reasonable movement of Red-throated Divers and Common Scoters.
Swallow counts still exceeded the 100 mark on several days at several sites on the east and south coast during the week but House Martin numbers have been low.

Ring Ouzel by Luke Delve

The forecast of wet and windy weather from the west over the next few days should pretty much knock the head on visible migration. However, it might ground a few migrants that move between fronts. Ring Ouzel is definitely one to look out for. The quieter moments will see migration resume again and could result in some impressive hirundine and finch movements towards the middle of the week, Goldfinch in particular.

The westerly airflow will hit much further south this week than it did last week; possibly just in time for the start of the Scilly season. Maybe the islands will get its first North American landbird of the autumn, and later in the week something from the east. Blackpoll Warbler and Blyth’s Pipit would do.


Friday, 26 September 2014

East meets West

After almost a month of easterly airflow that resulted in and amazing autumn for visible migration and the arrival of large numbers of scarce migrants along the east coast, the winds became westerly earlier this week, and as if by magic a Red-eyed Vireo  was found in the garden of the Sumburgh Hotel at the southern tip of Mainland, Shetland.  The first Semi-palmated Sandpiper of the autumn added to the westerly feel of around twenty Pectoral Sandpipers and up to half-a-dozen Buff-breasted Sandpipers.

Red-eyed Vireo by Joe Pender

However, it was still scarce migrants from the east that dominated and Wrynecks and Red-breasted Flycatchers continued to arrive, along with the first multiple arrival of Bluethroats, however, these were just the supporting cast for Britain’s third ever Masked Shrike that was found at Spurn, East Yorkshire on 20 September, overshadowing the Pechora Pipit on Mainland Shetland and the Lanceolated Warbler on Fair Isle.

Common migrants continued to arrive in force but as numbers of Whinchats began to fall during the week, Stonechats began to rise. Stonechat migration tends to peak around a month later than Whinchat, so there are plenty more of them to come yet. The first real movement of Linnets began mid-week joining the increasing number of Siskins on the move, and hirundines continued to pour out of the country but as is to be expected, in lower numbers than the last couple of weeks.


BirdTrack reporting rates for Whinchat (top) and Stonechat (Bottom)

It is a sure sign that autumn is moving on apace when the first Reed Bunting movement of the autumn occurs, 50 grounded on Hengistbury Head, Dorset and 65 at Spurn on 23 September give a flavour of things to come. Alba Wagtail (Pied and White Wagtails are difficult to separate on fly-over views so are often lumped as Alba’s) is also a late September migrant and records of these picked-up this week too.


So, what does the weather promise this week? It is going to be a game of two halves, at least until early next week, where there will be westerly airflow in the north, strong at times, and very light south-easterly airflow in the south. So from the Humber north, we might see a few more American waders, and possibly the odd landbird – historically, late September has turned up a few North American wood warblers. South of the Humber we can probably expect a few more scarce migrants from the east, which might include Red-flanked Bluetail and the odd Bluethroat. Late September is also a good time for the arrival of Short-eared Owl and Great Grey Shrike.

Friday, 19 September 2014

House Martins head off.

With easterlies still dominating it is hardly surprising that birds from the east have dominated too. Two species have occurred in exceptional numbers during the week, with around ninety Red-breasted Flycatchers reported and a similar number of Yellow-browed Warblers, with at least nine on Fair Isle, Shetland on 16 September.

Yellow-browed Warbler by Joe Graham

Common migrants were also drifted across the North Sea and there have been good numbers of grounded Pied Flycatchers, Redstarts and Whinchats, and Wheatear numbers have begun to increase. Swallows and House Martins have taken advantage of the light easterly winds and have poured out of the country. During the week, visible migration watchers at Hengistbury Head, Dorset, recorded over 26,000 Swallows and over 38,000 House Martins moving through the site.
The latter half of the week saw a few Redwings and Fieldfares arrive but these were outnumbered by Song Thrushes, although the number of thrushes on the move was small in comparison to the hirundines and Meadow Pipits.

Finches have also started to move, with small flocks of Siskins moving along the east and south coast although we will have to wait until later in the month before they, and other finches begin to move in any number. Compare the two BirdTrack graphs below for Siskin and Chaffinch and note how Chaffinch observations begin to rise later than Siskin.

BirdTrack reporting rate for Siskin

BirdTrack reporting rate for Chaffinch


The winds are forecast to turn northerly through the latter part of the weekend and then westerly and south-westerly during the early part of next week. However, irrespective of the direction they are forecast to be relatively light. Birds will take advantage of this and continue to move but we should see a shift in the species composition. Hirundine numbers are likely to be less impressive but Wheatear  and Robin ought to increase. We could also see Redwing becoming more widespread and who knows, they might bring something else with them.

Friday, 12 September 2014

It could be a big weekend.

With high pressure on the continent and low cloud over much of the UK for periods of time last week, a good visible migration showing was always going to be on the cards. It was with great anticipation of the spectacle that was to unfold that myself and BTO colleague Ieuan Evans made our way to the Spurn Migration Festival this weekend, and we weren’t to be disappointed.

Thousands, well over a thousand anyway, Meadow Pipits made their way south along the Spurn Peninsula, joined by hundreds of Swallows and House Martins, with a smaller showing of Sand Martins and a single Swift with them.

Whinchat by Mike Weston

Of the grounded migrants, Whinchats seemed to be everywhere, as did Yellow Wagtails. Spotted and Pied Flycatchers occasionally shared the same lookout perch, and the odd Redstart added a splash of colour. Warblers were well represented, Whitethroats, Lesser Whitethroats, Blackcaps, Garden Warblers, Willow Warblers and Chiffchaffs frequented the many hedges that criss-cross Spurn, along with a small number of Sedge and Reed Warblers.

Wryneck by Jill Pakenham

Scarce migrants were found too; at least three very showy Wrynecks were around, along with two or three Barred Warblers. Although the conditions weren’t ideal for a good seabird passage, a small number of Arctic Skuas, Sandwich and Common TernsRed-throated Divers and Gannets were on the move. However, top-billing went to the juvenile Long-tailed Skua that flew north along the beach.

So, was this a fair representation of what was happening at other migration watchpoints? Well, pretty much. Meadow Pipit migration is well underway (the BirdTrack graph shows this well), large numbers of hirundines were seen during visible migration watches on the south coast, and unprecedented numbers of Blackcaps moved through the western half of the country. There were lots of chances to catch up with Wryneck and Barred Warbler around the country, and in some east coast locations these were joined by the odd Red-backed Shrike.

BirdTrack Meadow Pipit graph


With mid September looming, the start of the peak migration period – mid September to mid October – what is on the cards for the next week? High-pressure is forecast to extend from southern Britain to northern Scandinavia, with resulting light easterly airflow. This means more of the same but it could be even more spectacular with large numbers of birds on the move. Pipits and hirundines will dominate again but we could see an increase in Wheatears and Skylarks joining in. The timing is also good for Honey-buzzards to be drifted out across the North Sea too. On the scarce migrant front, Red-backed Shrikes might outnumber Barred Warblers, and we could see a few Common Rosefinches, Icterine Warblers and the odd Bluethroat. On the rarity front, Great Snipe has to be favourite. The east coast has to be the place to be this weekend, my personal choice of venue being Blakeney Point, Norfolk.