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 October 2019

17th-24th October




During the last week the weather pretty much gave us what was forecast, westerly airflow across much of the country with some easterly winds in the north. The predicted movement of Siskins came to fruition, a record 5,740 were recorded flying over Sheringham, Norfolk on the 13th, with another 1,527 over Spurn, East Yorkshire on the same day. Grey Phalaropes were also on the move with birds being found in 16 different counties but with the majority in the south and southwest.

The predicted Siberian Rubythroat was also found when a male arrived on Shetland on 16th. Although none of the North American thrushes put in a showing plenty of new North American landbirds were found, including a Rose Breasted Grosbeak, a Myrtle Warbler and an east coast Red-eyed Vireo.

During periods of lighter winds thrushes from the east arrived in force with high counts of Redwings and Song Thrushes from several east coast watchpoints, accompanied by the first big movement of Ring Ouzels.

Ring Ouzel BirdTrack reporting rate graph

Species focus

Whooper Swan is amongst the heaviest of migratory birds, males caught in Britain weigh on average 10.2kg. The vast majority of birds wintering in Britain come from Iceland, where the population is estimated at around 16,000 birds. A few of these remain in Iceland throughout the winter but this only involves around 1,500 birds. The 800km sea crossing between Britain and Iceland is probably the longest undertaken by any swan species, six satellite tagged swans took between 12.7 hours and 42.4 hours to complete the journey. Around 200 birds from the Fennoscandian and western Russian population winter in Britain, with the vast majority wintering in continental Europe.

Whooper Swan by Andy Mason

Weather for the week ahead


As is to be expected for this time of the year the weather is forecast to be somewhat mixed. The early part of the period will be dominated by westerly airflow in the south and east/north easterly winds in the north, swapping during the middle of the period to north and easterly winds in the south to southwest and westerly winds in the north, with some periods of heavy rain at times and light winds at others. 

Snow Buntings by Neil Calbrade

We should see the arrival of Whooper Swans on the northerly winds, along with Snow Bunting, and later in the period thrushes and finches will be able to move in force across the North Sea and we could see the first big arrival of Bramblings and Chaffinches along east coasts. Ring Ouzel will also come into its own during the latter part of the period. On the scarce and rare front, there have already been a small number of Pallas’s Warblers seen but more could be on offer, we are now well into Radde’s Warbler timing but an accessible Siberian Blue Robin would go down a treat. North American thrushes have been remarkably absent during what is probably the best American autumn in over a decade, surely there must be at least one Grey-cheeked Thrush lurking somewhere.

Paul Stancliffe and Scott Mayson


Thursday, 10 October 2019

10th-17th October




It’s been a pretty lively week migration wise with birds turning up from all points of the compass, including the predicted Common Nighthawk from North America. One was found in Antrim and continued to show well until at least the 10th October. Birds from the east also arrived with a second wave of Yellow-browed Warbler very much in evidence and at least seven Red-flanked Bluetails being found from Shetland to Cleveland.

Common migrants flooded in and there were some impressive thrush movements. Observers at Spurn, East Yorkshire enjoyed watching 1,200 Redwing, 1,100 Song Thrush and 15 Ring Ouzel arrive on 6 October, along with at least 28 Yellow-browed Warblers.

Finches also began to arrive with the first real movement of Brambling and Siskin of the autumn.


BirdTrack reporting rate graph showing Siskins beginning to move

Species Focus

Breeding Siskins are found through most of Scotland and Wales and much of northern and southwest England, with the highest densities in landscapes dominated by conifer plantations. In Ireland they are more widespread in the west of the country. In winter, Siskins are even more widespread, being found in 83% of all 10km squares, with British and Irish breeders joined by continental immigrants. Siskin has seen its population increase by 44% between 1995-2016. At this time of the year when birds are on the move, Siskins can be found almost anywhere and will take advantage seed in gardens. Now is a great time to catch up with these acrobatic little finches.

Siskin by Edmund Fellowes

Weather for the week ahead

The weather for the week ahead doesn’t look too inspiring as most of the country looks like it will be locked in westerly airflow, and not all the way from the eastern seaboard of North America. It is a different story for the northern isles that will have a mix of northerlies at the beginning of the period and easterlies later in the period. If this forecast comes to fruition the northern isles could well be the place to be during this next seven day period.

Migration is in full swing and it will be during lulls in the wind that birds will move, given the chance. Siskin numbers should begin to build even if birds can’t make it across the North Sea. At this time of the year birds that breed further north in Britain should begin to make their way south. Redwings too will filter south, with the same story for Skylark and Reed Buntings, and during lighter winds some birds will make it across the North Sea, Starlings and thrushes are pretty strong fliers.

Grey Phalarope by Neil Calbrade

During storms and squalls along the west coast it is worth looking out for Grey Phlaropes and Sabine’s Gulls, October can be a good month for both of these. As for rare and scarce birds, there may well be one or two North American birds still to be found off the back of last week’s weather, Grey-cheeked and Swainson’s Thrush are favourite, but we should see one or two new birds in the northern isles – Siberian Rubythroat has become a little more regular in recent years but still remains a rare bird here, but with a short window of easterlies it may well be on the cards. Northerly winds in the isles should also bring the first big push of Glaucous Gulls, and maybe a few Little Auks too.

Paul Stancliffe and Scott Mayson



Thursday, 3 October 2019

3rd-9th October




It has to be said, for many of our common and scarce migrants September was a disappointing month with many species such as Redstart, Spotted Flycatcher, Whinchat, Wryneck and Red-backed Shrike being reported well below their historical reporting rates. The main reason is likely to be the lack of easterly winds which causes continental migrants to ‘drift’ across the north sea to the UK. For much of September, Britain and Ireland’s weather was dominated by Atlantic low pressures and the associated westerly winds that blew across the country, a pattern that was experienced last autumn, begging the question is this due to climate change or is it just a short-term change in our weather patterns?


BirdTrack reporting rate graph for Redstart showing the lower than
average reports from September.


The persistent westerlies across much of Britain and Ireland last week did, however, produce American passerines in the form of not 1 but 5 Red-eyed Vireos! 3 in the Republic of Ireland, 1 in Northern Ireland on Rathlin Island which was a first for the country and 1 in Cornwall. 2 Yellow-billed Cuckoos were also found, 1 on the Isles of Scilly and the other was found dead in East Sussex, and a Buff-bellied Pipit was identified on Bardsey Island. The Northern Isles of Scotland we're blessed with south easterlies and this produced a Brown Shrike on Out Skerries, a Daurian Shrike (once called Isabelline Shrike), Siberian Stonechat, Red-flanked Bluetail, Bee-eater, and a few Red-breasted Flycatchers, Barred Warblers, Yellow-browed Warblers, and Olive-backed Pipits. The rest of the UK saw good numbers of House Martins, Swallows, Meadow Pipits and Chiffchaffs on the move, as well as good numbers of Great White Egrets occurring across the UK as they continue their colonisation, now is a good time to search your local waterbody for this elegant heron.

Species focus


Ring Ouzels are a scarce breeding bird in Britain and Ireland with a preference for upland areas. The whole population is migratory with birds wintering around the Mediterranean basin. There are 2 main races in Europe, torquatus, which breeds in Britain and Ireland and Western Russia, and alpestris which breeds in montane areas from Northern Spain east to the Carpathians. The alpestris race has only been recorded a couple of times in the UK and is a short distance migrant, mainly moving to lower altitudes during the winter period. Ring Ouzels can migrate in large flocks with berries forming a substantial part of their diet at stopover sites. British breeding Ring Ouzels start migrating south in late September and continue into October, with a peak at the end of September probably representing the main departure period.

Ring Ouzel - early October can produce good numbers of this
relative of the Blackbird. Photo Paul Hillion



Other species that have a peak in their BirdTrack reporting rate in the coming week include Red-throated Diver, Pied Wagtail, Brent and Barnacle Goose, Grey Plover, Jack and Common Snipe and Kestrel. The northern European populations of Kestrel are migratory with birds from Scandinavia migrating as far south as West Africa. Some of these birds will pass through Britain as they head south with most observers assuming they are local birds when in fact they may have flown several hundred miles south already.

Jack Snipes arrive to the UK from Russia, Northern Finland
and Northern Sweden. Photo Allan Drewitt


Weather for the week ahead


We are now into one of the most exciting periods of the autumn and, if the weather forecast is correct, we might get some much anticipated easterly airflow over the weekend. Winds coming out of southern Scandinavia and across the North Sea on Friday into Saturday should help any migrants waiting to make the journey. We ought to see the first big arrival of Redwings of the autumn so far on the east coast, with Blackbirds, Ring Ouzels and Song Thrushes also likely to be part of this arrival. We could well be in for a second wave of Yellow-browed Warblers with several birds still being reported in Southern Finland and Sweden that will be heading south over the next couple of weeks. You can track their movements via the EuroBirdPortal.
These easterly winds are really only coming from southern Scandinavia but if anything has made it that far it could get drifted across the North Sea with species such as Rough-legged Buzzard, Pallid HarrierRustic Bunting, Citrine Wagtail, and Red-flanked Bluetail all possible and maybe something altogether rarer like Black-throated Thrush?
Later in the period strong westerlies are forecast for southern Britain and Ireland, at times coming right across the Atlantic, this could provide the chance of one or two more North American land birds – Common Nighthawk anyone?


Paul Stancliffe and Scott Mayson