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 28 September 2012

The perfect storm

Having been stuck in a westerly airflow for what has seemed like forever, the weather forecast, with the promise of a depression swinging south of the UK and heading north into Scandinavia looked too good to be true. The resultant easterly winds, coming straight out of Scandinavia and western Russia, just had to bring some eastern birds with them.

Birders were not to be disappointed. In fact the storm headed north earlier than was predicted and crossed right over Britain and Ireland, initially producing strong westerlies that turned into strong easterlies as it moved on north and west, as predicted eastern birds seemed to drop out of the sky. Weighing around 6g, over 100 diminutive Yellow-browed Warblers were found from Shetland to the Isles of Scilly. Yellow-browed Warbler breeds no closer to Britain than eastern Russia, with the majority breeding much further east. Rather than heading west into Europe these birds should have been making their way south and east into south and eastern Asia.  Joining these were one or two other eastern delights, up to four Lanceolated Warblers that should have been on their way to a similar area, and a couple of Booted Warblers that winter in India were two. However, pride of place must go the White’s Thrush that was found on the Farne Islands, this amazing thrush winters in China. As the storm tracked towards Scandinavia it also brought birds from there too. Around 100 Red-breasted Flycatchers and over fifty Barred Warblers graced our shores over the weekend.

Yellow-browed Warbler by Joe Graham

The westerly theme of the last few weeks was not to be left out completely. As the storm left American shores and crossed the Atlantic it brought with it Britain’s second ever Magnolia Warbler, and a Swainson’s Thrush, both to Shetland.

Common migrants also abounded with the largest fall of Goldcrests, Redstarts and Robins of the autumn so far. The BirdTrack weekly reporting rate for Redstart shows this nicely. Thrushes were also on the move with the first noticeable arrival of Redwings, Fieldfares and Song Thrushes. As more birds arrive and more people take part in the Winter Thrushes Survey, it will be interesting to see how they move through the country.

Redstart by Edmund Fellowes

So what will this weekend bring? The focus will once again turn to the west and north-west, where the next transatlantic storm will arrive, maybe bringing with it more goodies from North America. A Black-billed Cuckoo is long-overdue and would prompt many a birder to head west.

Friday 21 September 2012

Look to the east this weekend

With the UK seemingly stuck in a westerly airflow it is not surprising that the focus has very much been on birds from that direction. Over the last week there have been impressive numbers of transatlantic waders found on this side of the pond. Up to 16 American Golden Plovers, 75 Pectoral Sandpipers and at least 30 Buff-breasted Sandpipers provided the backdrop to the two juvenile Short-billed Dowitchers, still present from last week, and a scattering of Baird’s, White-rumped, Semi-palmated and Spotted Sandpipers.

Spotted Sandpiper by Peter M Wilson

With the strong westerly winds, movements of common migrants have been patchy with most coastal watchpoints experiencing some very quiet days. However, during periods of relatively calm winds hirundines made their move. On the 19th, an estimated 3,000 House Martins, 2,300 Swallows and 210 Sand Martins were in the skies over Christchurch Harbour. Slightly smaller numbers of the same species were counted at Spurn Point, East Yorkshire on the same day. Meadow Pipits have also begun to move with similar numbers reported from several sites along the east and south coasts.

With the promise of easterly winds for the latter part of this weekend, the focus ought to be on birds from that direction. With a Blyth’s Reed Warbler arriving on Orkney and an Arctic Warbler on Fair Isle this morning, things look good for migration watchers along the east coast.

Blyth's Reed Warbler by Andy Mason

As the wind turns, more easterly showers are forecast to move through during Saturday so ‘vis migging’ (observing visible migration) should be the order of the day. Meadow Pipits and Siskins should begin to move overhead in good numbers, accompanied by smaller numbers of redpolls and Goldfinches, along with a possible large movement of Swallows and House Martins. Showers overnight Saturday and early on Sunday morning could also ‘ground’ good numbers of other migrants that ought to include Whinchats and Stonechats. It will be worth checking out the latter for Siberian Stonechat.  An intriguing report from the bird observatory at Falsterbo, Sweden, tells of a very early movement of Nutcrackers through the site. We can dream!

Nutcracker by Stephen Menzie

We could also see the first noticeable arrival of Goldcrests to the east coast, and, if Goldcrests turn up then the first Yellow-browed Warbler of the Autumn is always a possibility. At this time of year a ‘fall’ of migrants is likely to contain a wide variety of birds that will include flycatchers, warblers and a few early moving thrushes. The first few Redwings were reported to BirdTrack earlier this week.

 So if you’re anywhere near the east and south coasts this weekend, particularly on Sunday morning, get out and enjoy what could be one of the busiest days of the autumn so far.

Thursday 13 September 2012

Autumn migration steaming ahead

Autumn migration is well under way and many summer migrants are now on the move. The main thrust this week has largely involved hirundines, with decent movements being observed of Sand Martin, House Martin and Swallow, particularly through the Pennines and along the east coast. Passerines have been thin on the ground at coastal observatories though,  with the exception of Chiffchaff and Blackcap, and to a lesser extent Wheatear, probably as a consequence of the strong westerly and north westerly winds we have been experiencing. The BirdTrack reporting rates for these species reflects this nicely. However, many species have been notable by their absence at coastal watchpoints.

Blackcap by Tommy Holden

This strong westerly airflow has brought American birds with it though, the most notable being two Short-billed Dowitchers, the second and third ever to be seen in Britain! One was found in Dorset and the other on the Isles of Scilly, whilst Britain's third Semipalmated Plover was found on the Western Isles. These American waders have had a good supporting cast of at least fifteen Buff-breasted Sandpipers from eleven different counties, and a Monarch butterfly on Portland, Dorset.

Fieldfare by Tommy Holden

Winter visitors have also been on the move with the first push of Pink-footed Geese into the north and east, and a record movement of Teal off Spurn Point, East Yorkshire, where 2,600 were counted passing south on the 10th. The first Whooper Swans arrived at the Ouse Washes on the 11th and small numbers of Fieldfare have been seen in at least five east coast counties.

The first arrival of Redwing could happen any day now. In some winters almost three-quarters of a million Redwings and Fieldfares spend the winter months in the UK. Clearly Britain is important for wintering thrushes. This winter the BTO are hoping to find out how our winter thrushes use the British countryside and are asking people that see these birds to report their sighting through the Winter Thrush Survey.

Red-eyed Vireo by Joe Pender

With the wind stubbornly set in the west what can we expect over the next few days? Well, more of the same, really! Northwestern Britain might be the place to be as the winds crossing the Atlantic will be at their strongest here, but the whole of the UK will be in this westerly airflow. With conditions like this a North American wader could turn up almost anywhere.  What might prove to be the vanguard over the next few days, the first American passerine of the autumn, a Red-eyed Vireo, was found on Unst, Shetland this morning.