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, 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.

Friday, 2 May 2014

Look north and east this week

It has been an interesting week this week with a few what might have been expected southern overshoots. At least twelve different Hoopoes, a couple of Purple Herons and several Black-winged Stilts, along with several Wrynecks and Red-rumped Swallows but I’m not sure anyone would have predicted the superb male Cretzschmar’s Bunting that was found on Fair Isle, Shetland, or the Alpine Accentor that was found in North Norfolk, as late April birds.

Alpine Accentor by John Harding

The BTO satellite-tagged Cuckoos have begun to arrive back at their tagging sites. Skinner was the first, arriving back in Norfolk on 22 April but has since been followed by Chris, BB and Whortle. This is the culmination of a 4,000 mile, 3 month journey from Congo. Check them out here

Many of our migrants have now arrived in good numbers, particularly the warblers. Blackcaps and Whitethroats seem to be everywhere; well at least they do here in Norfolk. However, there does seem to be fewer Swallows, House Martins and Sand Martins around; perhaps they are being held up by poor weather further south. Northern Spain and southern France do seem to be getting more than their fair share of cool, wet weather this spring, or maybe the cold spring last year took more of a toll than was thought.

Singing Blackcap by Adrian Dancy

Swifts didn’t really arrive during the week but as high pressure moves in from the north the resulting light winds should be perfect for a mass arrival, and the east coast could be the place to be. On Sunday and Monday the high pressure will extend from Yorkshire to North Africa, so more southern overshoots can be expected. Rock Thrush is a classic early May bird, as is Red-footed Falcon.

Rock Thrush by Nick Moran

During the early part of next week, the northern part of Britain will be hit by a run of weather fronts that have crossed the Atlantic, so as May is one of the best months to see an American sparrow on this side of the Atlantic, White-throated Sparrow is on the cards, and probably on Shetland.

Friday, 25 April 2014

Mixed weather could make for an interesting week

White-winged Lark and Rufous Bushchat was always a long shot but a Sardinian Warbler and Blyth’s Pipit did their best to represent southern and eastern overshoots this week.

It has been very much a stop-start week as far as visible migration is concerned, with a few days when both grounded migrants and birds moving overhead occurred in good numbers.  Reed Warblers turned up bang on cue, whilst early in the week 400 Wheatear and around the same number of Willow Warbler were grounded at Portland Bill, Dorset. These birds occurred in classic fall conditions, clear skies over the French coast, prompting them to leave and a bank of drizzle on the South coast of England, forcing them to land.

Willow Warbler by Neil Calbrade

It seems that there is a good chance of these conditions being repeated again at times this week, although the banks of rain may occasionally span the whole Channel and bring migration on the south coast to temporary halt. This will not be the case across the whole of the country though and there are some promising conditions for arrivals on the east coast. Easterly winds and showers forecast at least through to Monday/Tuesday on the English coast, and clear conditions on the other side of the North Sea, could result in migrants grounding from Norfolk to Shetland – where and when exactly will be determined by the local conditions on each day. If I could choose where to be over the next few days, in anticipation of a fall of spring migrants, I would choose Shetland on Saturday morning, Spurn Point, Yorkshire on Sunday morning, and the Norfolk/Suffolk coast on Monday morning.

Sunday morning on the west coast could also be interesting too. As a front moves in from the south-west it could also bring some skuas and terns with it, so, seawatching could be the order of the day.

So what might we expect? Well, pretty much more of the same. Swift numbers remained low this week but should increase rapidly next week. Spotted Flycatcher and Garden Warbler numbers should also increase but Hobby ought to be the bird of the week.  We have had our first Montagu’s Harrier, with the easterly airflow this week we could see a few more of these too.

Hobby by Jill Pakenham

The surprise rarity of the week has to be the male Northern Harrier that was seen over Portland, Dorset. Presumably this was a bird that arrived last autumn and wintered somewhere on the continent, and is making its way back north for the summer. It is interesting to think where this bird will spend the summer; maybe it will try to pair up with a Hen Harrier north of the border.

With the conditions forecast to be changeable it is difficult to say what we might get in terms of any rare or scarce migrants but Bluethroat, Wryneck and Red-rumped Swallow should be in the mix and, maybe an early Black Stork will put in an appearance.

Thursday, 17 April 2014

Spring migration steps up a gear

I have spent the last week on the Kent-Sussex border under blue skies, enjoying wall-to-wall sunshine and warm temperatures – not the best weather to experience any visible migration. On a one hour sample vis-mig watch at Dungeness on Monday morning I managed two Swallows, a Wheatear, a single Yellow Wagtail and a Pied Flycatcher that came in off the sea. 

There was a little more action over the sea. Common Scoter proved to be the most numerous migrating bird, in all twenty-seven flew west up the Channel during my sample hour, along with eight Gannets, two Red-throated Divers, nine Brent Geese and seven Whimbrel.

 Gannets by Jill Pakenham

It has definitely been quiet on the coast – the weather has just been too good and as a consequence any active diurnal migration will be happening high in the sky, out of earshot and eyesight. This is borne out by the number of summer migrants that have gone straight in land and are already on their breeding grounds. Pied Flycatchers and Redstarts are already singing in Welsh woodlands, a Nightingale was trapped during the week at its Cambridgeshire site and a few Cuckoos have been heard singing as far north as Northumberland, which bodes well for the BTO satellite tagged birds. We have three Cuckoos in Spain, with Skinner being the furthest north and Waller and Chris just a little further south. Any could make it back here during the next week. You can follow them as they complete the final leg of their mammoth journey here.

The mainly light northerly winds of the last week have been ideal for overshooting Mediterranean birds and we haven’t been disappointed. Star of the show was a Crag Martin in Yorkshire, however, three Hoopoes together in Devon and a flock of ten Black-winged Stilts on the Isle of Wight must take close second.  Red-rumped Swallow in Norfolk, White-spotted Bluethroat in Herefordshire and a Serin on the Outer Hebrides, A Tawny Pipit in Yorkshire, and two Bee Eaters on Scilly made for a good supporting cast. 

Of interest, we received evidence of outward migration across the North Sea in an email to the BTO. See below:

This bird landed on our cruise ship as it was near Shetland (heading towards Norway), but the weather was too stormy to dock there, so presumably the bird needed a bit of a rest.  

Skylark by Maureen Taylor

If the week belonged to any one species though it must belong to Ring Ouzel, a search on Birdguides returned one hundred and seventy-nine reports of birds from Scilly to Lancashire. So, what can we expect for the coming week.  Mid-April-mid May is the peak time for spring migration and we can expect almost anything to turn up. However, the best of it will always coincide with east/south-easterly airflow. This coming Sunday morning could be one of the best days of the spring so far to experience visible migration. The forecast is for a murky start, with the strong possibility of light rain, which will either bring moving birds lower or ground them altogether. Whimbrel will probably be the most obvious migrant next week but Reed and Sedge Warblers ought to also pile in, and by the end of the week many of us should also see a few Swifts. 

Ring Ouzel by Tommy Holden

On the scarcity/rarity front, with east/south-easterly wind forecast for the early/middle of the week we could be in for a treat with an eastern flavour. White-winged Lark is well overdue, as is Rufous Bush-Chat. We can but dream.