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 22 September 2017

From Russia With Love?

When it comes to pace of change in the avian world, it's hard to beat late September in western Europe. Summer visitors are departing en masse, as evidenced by the estimated 100,000 House Martins logged at Sandwich Bay Bird Observatory on 20 September, with large movements of that species and Swallow noted at several other locations. At the same time, wintering birds are starting to pour in, reflected by the rapidly rising BirdTrack reporting rates of waterfowl like Brent Goose and Shoveler.

Historical BirdTrack reporting rate for Brent Goose

The vagaries of the weather at this time of year adds to the rapidly changing picture. Whilst we were discussing American waders and passerines last week, attention is now turning towards potential arrivals from the east, as a large area of high pressure – with associated easterly airflow – is building over Russia. Two Pallas's Grasshopper Warblers, a species that breeds from central Russia eastwards and typically winters in southeast Asia, have already arrived in the UK, one in north Norfolk and one on Fair Isle, and a female Siberian Thrush made it to Shetland. Perhaps rarer still, these days at least, was a Yellow-breasted Bunting found on Out Skerries, Shetland on 20 September. This species is thought to have suffered a 90% population decline, owing mainly to trapping in its non-breeding range, and is now classed as Endangered.

More common species to look out for this week include departing Chiffchaff and passage Wheatear, both of which reach their peak autumn reporting rates on BirdTrack this week. That said, it seems to have been a poor autumn for Wheatears to date, so it will be interesting to see if this picks up in the remainder of September. It's also the best week of the year for Barred Warbler, a lumbering Syvlia warbler that breeds no closer than eastern Germany and southern Scandinavia but is seen regularly in the UK in small numbers each autumn, particularly on the Northern Isles and down the east coast. Waders will remain a feature too, with Dunlin and Snipe both expected to feature on up to 15% of complete lists this week. At the scarcer end of the spectrum, it's the best few weeks of the autumn to find a Dotterel.

Juvenile Dotterel by Nick Moran

Given that the easterly airflow is originating in the Pechora area of Russia, at the northwestern end of the Ural Mountains, it seems reasonable to think that a Pechora Pipit or two might be on the cards for those lucky enough to be birding some of Britain's more northerly outposts. For the rest of us, there'll be lots to enjoy over the next week or so, perhaps including the first big arrival of Redwings. Listen out for their 'tseeep' call over coming nights, particularly on damp, misty evenings when arriving birds will tend to be lower and therefore easier to detect.

Redwing by Nick Stacey
Redwing by Nick Stacey
Nick Moran

Friday 15 September 2017

More waders from the West

Several more North American waders were found this week, as the westerly airflow – very strong at times – continued to dominate. A Stilt Sandpiper appeared at Lodmoor RSPB, Dorset on 11 September, where it was quickly joined by a diminutive Least Sandpiper! The same or another Least Sandpiper was retrospectively identified on the Axe estuary, Devon on 7 September, after the astute observer recognised the Lodmoor bird and scrutinised his blurry photographs of a 'peep' that looked wrong for Little Stint but was too distant to identify in the field. The Spurn Migration Festival (aka Migfest) got in on the act too, with this blog's regular author, Paul Stancliffe, locating an incoming Long-billed its call!

Spurn's Long-billed Dowitcher shortly after it touched down, by Nick Moran

The American Redstart that was found on the remote island of Barra in the Outer Hebrides last week hung on, proving popular with Barra regulars and long-distance twitchers alike. It's the sixth living individual of that species to reach the UK but the first for 32 years (a long-dead one was found on a tanker in late December 1993, the ship having travelled from Texas to Shetland via Angola!).

The westerly storms also brought seabirds that are trying to make their way southwards through the North Atlantic close to – and even over – the mainland. West coast based observers enjoyed a glut of Leach’s Petrels and Sabine’s Gulls, whilst all four species of skua have been seen from both the west and east coasts. Great Skuas were very much in evidence on the east side of the UK on 14 September, with notable observations of 170 – including one flock of 110 – flying inland from Huttoft Bank, Lincolnshire and 62 that flew south over Foul Anchor, Cambridgeshire. These birds were presumably taking the known 'short cut' between the Wash and the Severn, though the large numbers involved were probably a result of the weather conditions.

Following the movements in the last few days, the BirdTrack reporting rate for Great Skua
must surely be set to rise towards its mid September historical peak

The storms also pushed a few Manx Shearwater far inland, with a bird taken into care in Ely, Cambridgeshire on 14 September and another found dead in Stowmarket, Suffolk.

Meadow Pipits have begun to move in earnest with over 11,000 individuals counted moving over Spurn, East Yorkshire during Migfest. These were joined by an impressive movement of Swallows and House Martins over the same weekend, when around 1,500 of each were counted. A few Swifts hang on, the BTO's own Nunnery Lakes reserve hosting one as late as 15 September.

Pink-footed Geese started arriving in the first week of September but numbers on the move increased in the last few days. The weather seemed to displace some of these, too, with a skein of 31 over northwest Worcestershire on 14 September being unusual so far south this early in the year.

Migrating Pink-footed Geese by Chris Mills

A mid September BTO Bird Migration Blog post couldn't end without mention of a popular – and increasingly numerous – migrant, Yellow-browed Warbler. Shetland received its first on 9 September, whilst mainland UK had to wait until 14 September, when birds were logged in Durham, East Yorkshire, Lancashire and Norfolk. Even the briefest 'window' in the weather will see more of these spritely Phylloscopus warblers arrive.

Nick Moran

Friday 8 September 2017

Look to the west

Airflow from the west has dominated the last week and so it is perhaps not that surprising that Nearctic waders have been well represented. At least seven Baird's, five Semipalmated and five Buff-breasted Sandpipers were found, along with two Lesser Yellowlegs and two Hudsonian Whimbrels.

Buff-breasted Sandpiper by Ron Marshall

Yellow Wagtails are still on the move but have been increasingly joined by Grey and alba wagtails, the latter involving both White and Pied Wagtails. The last few days have also seen the first real movement of Meadow Pipits, with notable counts of 85 at Hengistbury, Dorset on 6 September and 250 moving over Portland, Dorset on the same day.

Meadow Pipit by Jill Pakenham/BTO

September is also the month to enjoy tern passage, and this week hasn't disappointed. Offshore movements of Common, Arctic, Sandwich and Black Terns being  reported fro several coastal watchpoints. When terns are on the move, skuas aren't far behind and a few Arctic and Great Skuas have followed the terns. As the month progresses, both tern and skua passage should build. Early September is also a good time to look for Long-tailed Skua at coastal watchpoints.

Reporting rate of Sandwich Tern on BirdTrack

Migrant passerines found in the last few days include Red-backed Shrike, Wryneck, Ortolan Bunting and Bluethroat arriving from continental Europe despite the westerly wind. Two other typical autumn migrants, Common Rosefinch and Barred Warbler should also start appearing at coastal headlands soon.

Barred Warbler by Moss Taylor/BTO

The weather forecast for the next four or five days suggest that westerly airflow will once again dominate, with several low-pressure systems set to cross the Atlantic. These will very likely bring more shorebirds, perhaps a few more Buff-breasted Sandpipers or American Golden Plovers to our shores in the days ahead. An American Redstart was found on Barra in western Scotland yesterday, the first record in Britain since 1985. Will more Nearctic warblers be found over the weekend?

This weekend sees the fifth Spurn Migration Festival – the BTO team are there all weekend. If you are planning on going to the festival, why not drop by and say hello to the team?

Paul Stancliffe and Stephen McAvoy

Friday 1 September 2017

September is here and birds are on the move.

There are still one or two Swifts being seen over the BTO headquarters here in Norfolk but most have now gone, the last few will probably join them any day now. House Martins and Swallows are also on the move but with reports of nests containing young of both still coming in they will be around for a while yet.

One of the biggest movements seen this week has been Yellow Wagtail, around 1,000 were estimated to be on Portland, Dorset over the weekend, with around 200 still present on 29 August.

Yellow Wagtail by Jill Pakenham

A few Pied and Spotted Flycatchers and Redstarts and Wood Warblers have begun to turn up at coastal watchpoints, along with a few Tree Pipits. Willow Warblers have reached double figures at many too. A few Chiffchaffs have been mixed in with the Willow Warblers but it will be a couple of weeks before the numbers really start to build.

The first Fieldfare of the season was seen on Fair Isle on 29 August, giving a flavour of what is to come, and scarce migrants also began to feature, at least three Barred Warblers, 18 Wrynecks, two Greenish Warblers and a Woodchat Shrike and a few Red-backed Shrikes and Common Rosefinches.

Fieldfare by Edmund Fellowes

Scarce waders were also represented with around thirty Pectoral Sandpipers, four Buff-breasted Sandpipers and a scattering of Dotterel being seen during the week, but pride of place must go to the Pacific Golden Plover that was found on Papa Westray, Orkney on 26 August.

Ospreys have been reported from most counties and a few Honey Buzzards have been on the move too, so it is well worth keeping an eye on the sky during the next week.

Honey Buzzard by Graham Catley

The weather forecast for the early part on next week looks promising for the arrival of more Buff-breasted Sandpipers, with a low pressure system tracking across the Atlantic, we might also get something much rarer following on from the double-billing Yellow Warblers of last week. It’s about time we saw another Yellow-throated Vireo in the UK. During the early part of next week High-pressure over Scandinavia might just push a bit of east in the wind over the northern isles and could bring a few more Barred Warblers, Wrynecks and Red-backed Shrikes with it.