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, 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.

Friday, 5 September 2014

Warblers, wagtails and a Wryneck

With easterly airflow dominating this week migration has stepped-up a gear. Good movements of Pied Flycatcher, Swallow, Chiffchaff, Whitethroat, Yellow Wagtail and Tree Pipit have been seen at several coastal watchpoints; over 3,000 Swallows moved through Hengistbury Head, Dorset, on the 2nd September alone.

BirdTrack graph showing the Autumn increase in records

From the east, Wryneck topped the bill, over a hundred were reported, from the Isles of Scilly to Shetland. Other eastern delights included up to 10 Greenish Warblers,  around forty Barred Warblers and four Citrine Wagtails. Below is a link to video footage of a Wryneck that frequented a garden in Spalding, Lincolnshire.

Wryneck by Jill Pakenham

Out in the north Sea, things were a little quiet, although a single Sparrowhawk, 3 Garden Warblers, 1 Pied Flycatcher, 2 Redstarts and2 Meadow Pipits did visit the research vessel that is stationed in the Dutch sector of the southern North Sea.

With the weather looking a little unsettled for the early part of the weekend, and high pressure building for the early part of next week we could be looking at more of the same for next week, although the numbers of common migrants on the move could increase dramatically. We can look forward to more Meadow Pipits and Yellow Wagtails, a big increase in the hirundine movement, Wheatears turning up in odd places; whilst offshore, terns and skuas are well worth looking out for.

For those attending the Spurn Migration Festival (, the BTO will have a stand and be taking part in migration walks and talks, it is also looking very promising for some good visible migration – see you there.

Friday, 29 August 2014

Easterly airflow brings in some scarcities

The last few days have seen some easterly airflow from the continent with the resultant arrival of a few classic late August/early September migrants.

Amongst the common migrants, Whinchat has featured strongly. Willow and Sedge Warblers have also begun to move in numbers and the first real movement of Redstart, Pied Flycatcher and Yellow Wagtail is underway.

The BirdTrack graph for Redstart above shows this second reporting peak as birds begin to move out. 

With easterly airflow at this time of the year there is always going to be some scarcity interest and this was definitely the case. Barred Warbler, Greenish Warbler, lcterine Warbler, Wryneck and Common Rosefinch were bang on cue but the Fieldfare that was seen coming in off of the sea at Sheringham on 28 August was particularly early.

Waders have continued to move through but not in the numbers that might be expected. July saw reasonable numbers of adult birds on the move but the number of juvenile birds has been low. Maybe the breeding season further north has been a poor one, or might it be that the fairly consistent westerly airflow through most of August has meant that they have been moving through on the other side of the North Sea?

There is some nice evidence of birds crossing the North Sea in the last few days. The deck of a research vessel in the southern North Sea has seen a few Pied Wagtails, a couple of Garden Warblers and a lone Reed Warbler, read more here

Swift migration is well underway with the majority probably already in southern Europe, although small numbers are still being seen migrating through coastal watchpoints.

The BirdTrack reporting rate for Swift

What can we expect during the next few days?

Westerly airflow, becoming light during the early part of next week, won’t quite result in a similar arrival of scare passerines but we might see a few Pectoral Sandpipers and possibly the first Buff-breasted Sandpiper of the autumn courtesy of Hurricane Cristobal that will track across the Atlantic before heading north towards Iceland later this weekend.

The lighter winds and high pressure early next week should encourage some of our common migrants to move and we could see an increase in Wheatears, Wagtails and warblers at migration watchpoints.



Friday, 18 July 2014

Wonderful waders

The summer months can seem rather quiet after the heady spring migration days but now is the time for waders that have either finished, or failed their breeding attempts in the high Arctic to be on the move. Having little reason to remain in the far north, these birds will now begin the journey to their wintering areas, with many passing through Britain on their way south.

Black-tailed Godwit by Nigel Clark

Icelandic Black-tailed Godwits have been popping-up at both coastal and inland sites this week, and the number of migrating Whimbrel, Curlew and Redshank is beginning to increase. Whilst it is exciting to see common waders on the move, the real excitement comes in what might be moving with them, and anyone looking for rarer waders were not to be disappointed this week. Top billing has to go to Britain’s fourth ever Great Knot, found during a Wetland Bird Survey at Breydon Water, Norfolk. The same county also hosted a Stilt Sandpiper and a Black-winged Pratincole, whilst just over the border, a Collared Pratincole was found at Minsmere, Suffolk.

Mediterranean Gull by Andy Mason

It is not only waders that are on the move, during the last week or so, several thousand Swifts have been recorded heading south over Spurn, East Yorkshire, with the highest single day count reaching 9,050 birds.
Gulls are a lot more evident too, here at the BTO headquarters in Thetford, post breeding Lesser-Black-backed and Black-headed Gulls have begun to frequent the nearby green spaces, and the annual passage of Mediterranean Gulls has also got underway, double figures of this species were recorded on the move at Breydon Water, Norfolk, and Christchurch Harbour, Dorset. A colour-ringed second-summer bird at the latter site was ringed as a chick in a colony in Lithuania in 2012, giving us a clue as to the possible origin of some of these passage birds.

Our satellite-tagged Cuckoos are also well on their way, with the first three birds having successfully crossed the Sahara desert, two from Devon and one from Sherwood Forest. Only one of the tagged birds – twenty-two in all – remains in the UK, in Norfolk, the other eighteen are spread across nine different countries, from England to Sudan; truly birds without borders. Follow all of them as they continue on their journey south on the BTO website.

Wilson's Petrel by Joe Pender

Seawatching could also be the order of the day for west coast-based birders. The first Wilson’s Petrels have been seen from Scilly pelagics this week, along with the first few Cory’s Shearwaters from various sites.

The weather forecast for the next few days, and into the early part of next week is a mixed bag, but there is a short period of north-westerly wind forecast for northern Britain over the weekend, which could result in more Black-tailed Godwit, Redshank and Whimbrel on the move. A return to easterly airflow – forecast for Monday - should see Common Scoter on the move, and the possibility of one or two more exciting waders from further east. I’d be happy with either Greater, or Lesser Sandplover, and to round off the trio perhaps an Oriental Pratincole might grace an eastern county.

Paul Stancliffe

Friday, 23 May 2014

Migration slowing down

This week has been a classic mid-may week. Passerine numbers have slowed right down – most are now here and many are already feeding the young of their first broods – however, waders have been more prominent with some top drawer scarcities joining the Dunlin, Sanderling, Turnstone, Bar-tailed Godwit and Whimbrel as they pass through the UK to arctic breeding grounds. From the east, came a Terek Sandpiper, found in Lincolnshire and a Broad-billed Sandpiper also in Lincolnshire. Two summer plumaged Spotted Sandpipers, a couple of Lesser Yellowlegs and Pectoral Sandpipers and a Buff-breasted Sandpiper came from the west, whilst the south produced a further influx of Black-winged Stilts and a single Kentish Plover, we can expect more of the same over the next couple of weeks.

Terek Sandpiper by Andy Mason

With over twenty birds being reported at sites from the south coast as far north as Yorkshire, Bee-eater has to be the bird of the week. Other southern overshoots included at least ten Black Kites, five Hoopoes, five Red-rumped Swallows and at least three Great Reed Warblers, whilst a Red-footed Falcon and a handful of Red-backed Shrikes and Bluethroats and, at least two White-winged Black Terns came from the south-east.
Bee-eater by Su Gough

The biggest rarity of the week came in the form of one of the world’s rarest birds, a Cahow, or Bermuda Petrel, seen from a survey vessel 170 nautical miles WNW of County Kerry, and with a world population of around 500 birds it somewhat overshadowed Britain’s eighteenth Calandra Lark, found on Fair Isle.

With low pressure wheeling over the country and drawing air in from a southerly direction we may well see an arrival of Quail and a few classic mid-May birds such as Red-backed Shrike, Marsh Warbler and Wryneck, and if we get any appreciable easterly airflow, maybe a rarity such as Oriental Pratincole or Marsh Sandpiper, and if you’re out and about birding over the Bank Holiday weekend, don’t forget to submit your complete lists to BirdTrack and make your observations count.

Friday, 9 May 2014

World Migratory Bird Day

This weekend sees the celebration of World Migratory Bird Day, an initiative that seeks to raise the profile of migratory birds across the world.

Cuckoo by Steve Ashton

Migration is probably one of the most hazardous things that any bird may undertake, our satellite tagged Cuckoos are testament to that. We have lost birds to bad weather; Martin the Cuckoo was caught in a severe and unseasonal hail storm in southern Spain in spring 2012. Other birds have been defeated by the extremely arduous crossing of the Sahara, whilst some found it difficult to fatten-up during the wet, cold 2012 summer here in the UK, hampering their progress south.

This spring seems to have been good to our Cuckoos and currently seven tagged birds have made it back to the UK, three to Scotland, three to East Anglia and a single bird to Dartmoor, almost at the exact location where he was tagged in 2013. Two birds are still on their way and are in France and Spain but we have lost two birds on the way. One, Tor, is almost certainly down to tag failure, his transmissions had become patchy during the winter, and the other, Ken, as he was preparing for his northward crossing of the desert – maybe he just couldn’t find enough food, or perhaps he was taken by a predator, we will never know for sure.

There are plenty of natural hazards but many migrants also have to run the gauntlet that the modern world throws at them. Chris Packham recently highlighted the plight of European migrants as they migrate through Maltese airspace, read more here. A small number of British migrants also use this route and 29 recoveries of birds ringed in Britain, of 14 different species, have come from Malta. Among these have been two British-ringed Cuckoos; indeed two of our satellite tagged birds have flown directly over Malta on their way to Congo.
Black Kite by Jill Pakenham

Whilst many birds perish during migration, many successfully make it back. The weekend just gone saw the mass arrival of Swifts to the UK, the first wave of Spotted Flycatchers and the first Nightjar. There was also a good showing of southern overshoots, with multiple arrivals of Hoopoe and Black Kite, and several species of warbler, including a singing Eastern Bonelli’s Warbler in Northumberland.

The weather over the next few days will make it difficult for migrants to move. Strong winds and heavy rain is forecast to give way to light winds and warm weather for the latter part of the week and if this is the case we could see birds moving in force again – the spring is getting on and there will be a sense of urgency to get to the breeding grounds for these later arriving birds. More Spotted Flycatchers, Turtle Doves, Nightjars and House Martins should take advantage of any windows in the weather.

Scops Owl by Peter M Wilson

From mid-week we could see more overshoots but we are coming into the period where anything could turn up. An obliging Scop’s Owl would fit the bill, but given the Atlantic lows during the early part of the week maybe we should be looking to the west, we are overdue another Lark Sparrow.