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.

Wednesday 30 October 2019

31st October - 6th November

The past week saw much of the country under the influence of southerly and westerly winds which then swung around to a more northerly direction over the weekend onwards before finally bringing in a run of much anticipated easterly winds at the start of the week.  Whooper Swans took advantage of the northerly element and the BirdTrack reporting rate shows a spike in reports as birds arrived from Iceland. Peak counts included 369 at Teviot Haughs, Borders on the 26th and 133 from Hornsea Mere, Yorkshire,  the previous day. Whilst reports of Redwing started to level off, those for Fieldfare increased, this species typically arrives later than Redwing and the first big arrival happened over the weekend and into the start of this week. In Cumbria 7897 Fieldfare were recorded on the 29th and 5947 were seen at a location in Lancashire the next day. Big movements of Woodpigeon are a feature of settled weather at this time of year and with clear skies and light winds at the start of the week some locations recorded large numbers of birds on the move with a peak count of 64,000 in Cardiff on the 28th being the highest number reported via BirdTrack.

BirdTrack reporting rate for Whooper Swan showing a spike in reports last week

Mixed in with the commoner migrants were a few rarer species with top billing going to a 1st winter Steller's Eider on Orkney, this is the first since November 2000 and the last truly twitchable bird was in the 1980s! Other notable species included Tengmalm's Owl in the Scottish highlands, which will prove popular if it gets refound, the returning Pacific Diver in Ireland at Crookhaven, Swainson's Thrush on Mainland Shetland, Two-barred Warbler in Ireland (a first for Ireland), and the returning White-winged Scoter in Scotland. As for the species we predicted in the last post, an Upland Sandpiper was found in Cornwall, 6 Hoopoe's were reported and single of both Pallid Swift and Red-rumped Swallow were also reported.

Species focus

Cool, clear conditions with light winds in late October/early November provide the ideal recipe for Woodpigeon migration. Little is known about Woodpigeon movement in the UK but as a species, it is found from western Siberia in the east to the Faeroes in the west, and as far north as Fennoscandia and south as North Africa.
Some continental Woodpigeons move south in large numbers, during the last week almost a million birds have moved south through Falsterbo, southern Sweden, and small flocks have been seen heading out to sea on our south coast.
It is thought that any movement of Woodpigeons seen here either involves birds that have been drifted across the North Sea and are carrying on south, or a movement from the north within the UK. It is also thought that many of the birds seen heading out to see don’t go very far before doubling back. However, there is evidence of birds continuing their journey south with flocks being recorded leaving Cornwall then being seen over the Isles of Scilly, the Channel Islands and the Brittany coast.
Many of the continental birds head to Spain and Portugal to feed on the acorn harvest, via a flight around the western end of the Pyrenees, some may take a route around the eastern end of the mountains but this is far from clear – there is still a lot to learn.

Wood Pigeon - Photo by Allan Drewitt

Weather for the week ahead

For the start of the review period, the easterly winds from the last couple of days remain and feed in air from Germany and the near continent but as we move towards the weekend an Atlantic low sweeps across the country changing the wind direction to south/south-westerly and also bringing rain to many parts. From Monday this low-pressure system deepens and tracts north east dragging in colder air from the very far north with day time temperatures across much of Britain and Ireland struggling to get into double figures. 
The easterlies at the start of the review period could see an increase in Hen Harriers, Woodcock and Short-eared Owls as their peak reporting rates are at this time of year as birds arrive here from their breeding grounds further north and east. Keep an eye out in larger gardens, woodland parks and field edges for Woodcock that seek shelter when they first arrive. These winds could also drag in a rare Wheatear such as Pied or Desert and maybe a few more Pallas's Warblers or the first Hume's Warblers of the autumn. 

BirdTrack reporting rate graph for Woodcock.
Woodcock - Photo by Hugh Insley
The Atlantic low that will be with us from the weekend onwards opens up a slight airflow from America and could yield American Robin, which are typically late migrants, Franklin's Gull, or maybe even a Cliff Swallow or Chimney Swift? As this system moves across the country it produces a brief run of easterly wind for northeastern Scotland, the Northern Isles and parts of northern Britain and given that some parts of Scandinavia are experiencing an influx of Rose-breasted Grosbeak, a large finch of the Tiaga zone, many birdwatchers will be hoping for a repeat of 2012 with a bird arriving this side of the north sea, preferably somewhere easily accessible. You can read more about this influx here
The run of southerlies brought about as low pressure moves across the country could produce more Pallid Swifts and Hoopoes
Once this low-pressure system arrives in scandinavia at the start of next week the resulting northerly winds should see an arrival of white-winged gulls (Iceland and Glaucous), Long-tailed Ducks, Little Auks, Velvet Scoter, Snow Buntings, Purple Sandpiper, and numbers of Common Gulls and Black-headed Gulls will continue to build as birds arrive from further north and across Europe. Mixed in with these could be rarer species such as King Eider, White-billed Diver and maybe even an Ivory Gull or Brunnich's Guillemot who knows, one thing is for sure at this time of year, you never know what is going to turn up! 

Snow Bunting - Photo by Allan Drewitt

Scott Mayson and Paul Stancliffe

Thursday 24 October 2019

24th-30th October

The past week has seen rare birds from all points of the compass arrive in the UK with Short-billed Dowitcher (Louth), Myrtle Warbler (Galway) and American Black Tern (Dorset) from the West, Hornemann's Arctic Redpoll (Fair Isle) from the North, Eastern Yellow Wagtail (Scilly Isles) , and Collared Flycatcher (Kent and East Sussex) from the East, and Lesser Kestrel (East Yorkshire), Pallid Swift (East Yorkshire) and Isabelline Wheatear (Lundy and Isles of Scilly) from the south.
The past week also saw a good arrival of Thrushes with large flocks of Redwing and Song Thrushes, Miles Hill in Hampshire recorded 9600 Redwing on the 21st October. Ring Ouzels were also reported from several locations and the reporting rate graph from BirdTrack shows the spike in reports carrying on from the good numbers arriving the previous week too.

BirdTrack reporting rate graph for Ring Ouzel showing a spike in
reports last week.

Reports of finches such as Brambling, Siskin, Lesser Redpoll, and Hawfinch increased throughout the week and the numbers of these species will only increase over the next few weeks as more birds arrive from the continent. Numbers of Robin and Dunnock, both of which are often not thought of as migrants, also increased during last week as birds arrived from Europe for the winter.

Species Focus

Every winter large numbers of Starlings cross the North Sea to spend the winter months in the UK, adding to the spectacle of murmurations across the country. Seeing large flocks of Starlings wheeling around the sky it is easy to forget that all is not well, our breeding population has fallen by 73% since 1991. The highest numbers of ringed Starlings recovered in countries from overseas go to Denmark and Lithuania, a good indication of where many of our wintering Starlings originate. Starlings are also fairly long-lived birds, the record is held by a bird that was ringed near Ipswich, Suffolk on 20 November 1983 and found dead in Phillipova Gora, Demianski Rayon, Russian Federation on 15 July 2001, 2,122km from the original ringing location. Starlings are strong fliers and during light winds or winds with an element of east in them during the next few weeks, we should see flocks of them arriving on the east coast and heading off inland.

Starlings arrive in the UK from across Europe - Photo John Harding

Weather for the week ahead

As has been the case for much of the late autumn this year the weather over the next week looks to be a mixed bag with the wind coming from several directions. This can be a good thing with the weather 'mixing' things up a bit and could result in a good variety of species arriving, departing and passing through the UK. The next couple of days sees an east-west split with western parts of the UK having westerly winds that are coming off a low situated between the UK and Iceland. This could bring in a few more Whooper Swans and Pink-footed Geese from Iceland. This short run of westerlies could also bring in a vagrant American wader such as Upland Sandpiper or Wilson's Snipe to somewhere like the Isles of Scilly or Ireland. Eastern and southern coasts will be dominated by a southerly airflow which may result in species such as Hoopoe, Red-rumped Swallow, and Pallid Swift reaching us. From the weekend the wind direction for the majority of the UK turns first more northerly then easterly by the middle of next week. Species that are likely to occur whilst the wind is of a northerly direction include Leach's Petrel, Pomarine Skua, which have their peak reporting rate in BirdTrack for the coming week, and Little Auks which can sometimes be seen in large numbers from North Sea locations, but they can also turn up inland as they have been known to join migrating flocks of Starlings arriving from Europe.

Little Auk - Large numbers can be seen after strong northerly winds
at this time of year. Photo Morris Rendall.
As the wind direction turns more easterly so the variety of species making landfall across Britain and Ireland increases. Wildfowl, such as Wigeon, Pintail and Shoveler, will arrive here from their breeding grounds in Scandinavia and northern Russia and large flocks can often be seen arriving over the North Sea. So far it has been a poor autumn for Great Grey Shrikes with very few reported but a few days of sustained easterlies could bring more birds across the North Sea. These same winds should also see more Short-eared Owls, Black Redstarts, Firecrests, and Woodcocks arriving from across Europe. Thinking a bit rarer easterlies at this time of year could produce Siberian and Stejnegers Stonechat, Hume's Warbler, Dusky Warbler or maybe a rare Asian Thrush such as Dusky or Eyebrowed.

Paul Stancliffe and Scott Mayson

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