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, 20 May 2016

What an amazing week

Calandra Lark by John Harding

If rare birds are what makes you tick, the last week or so has to be one of the best spring periods on record. Last week’s Caspian Stonechat, Calandra Lark and Dalmatian Pelican (if accepted as a wild bird) would take some beating and it would take a very special trio of birds indeed. However, Britain’s second ever Green Warbler, found on Shetland, Britain’s first ever spring Blyth’s Pipit and the first ever Lammergeier (if accepted as a wild bird) seems to have done the trick.
But what of our common migrants?

The week has seen a rush of hirundine passage, particularly through a few south coast watchpoints. During the morning of 19 May sample counts at Portland, Dorset suggested that Swallows were passing at a rate of 550 per hour. It is interesting to note though that the BirdTrack reporting rate for House Martin is behind the historic reporting rate, so we might have a large arrival of House Martins still to come.

House Martin BirdTrack reporting rate 

Spotted Flycatcher migration seems to have stalled in the cooler northerly airflow that we have been experiencing. There might be a window in the weather after early rain on Sunday morning when fairly calm conditions are forecast on either side of the English Channel, but by early next week we will be back in northerly airflow again.

The forecast for northern Britain is a mixed bag with the early part of the week looking quite stormy at times. This could be good news for anyone heading north to catch up with Long-tailed Skuas, as the birds could be pushed close to the northern isles, they will almost certainly be accompanied by Pomarine Skuas too.

Nightjar by Neil Calbrade

Any still, clear conditions during the next week will also help any Nightjars that are on the move. Some birds are already back at their breeding sites but the BirdTrack reporting rate shows they will continue to arrive during the next couple of weeks. And of course, waders will continue to push north when conditions allow too. Wood Sandpiper and Temminck’s Stint are good mid to late May birds to look out for.

Nightjar BirdTrack reporting rate


Friday, 13 May 2016

The easterlies blow their magic

Almost constant easterly airflow during the last week or so had the desired effect on bird migration and a sumptuous array of rare and scarce birds arrived our shores.

Black Terns can be a bit hit and miss, but this spring, so far, there has been a steady migration of them through the country, drifted west by the easterly airflow. The BirdTrack reporting rate graph shows this beautifully.


Joining the Black Terns were a couple of Whiskered and White-winged Black Terns, completing the "marsh tern" set. Most records were from the Midlands, where wader passage also noticeably picked up. Several summer-plumaged Grey Plover, Little Stint and Curlew Sandpiper were found at wetland sites such as Swillington Ings, West Yorkshire or Rutland Water, Leicestershire.

Black Tern by Graham Catley / BTO

Warblers also appear to have taken advantage of the conditions and finally made it back to their breeding sites. Blackcap, Chiffchaff, Reed and Sedge Warbler all exceeding their historic reporting rate on BirdTrack. Reed Warbler especially showed a much higher reporting rate than usual in the second week of May.


Rarer migrants have also a distinctly eastern or south-eastern feel to them with Eastern Bonelli's Warbler, Caspian Stonechat and Calandra Lark noted in recent days. Grey-headed Wagtails on their way to breeding grounds in Scandinavia have also been noted at several east coast sites, as were the first Wryneck, Red-backed Shrike and Bluethroats.

A Dalmatian Pelican found in Cornwall last Saturday looked for a while like it may have been a genuine wild bird, having over-shot its breeding grounds in the Balkans. However, careful comparison of feather details with other Dalmatian Pelicans noted in northern Europe in recent weeks shows an almost much more interesting scenario. First seen in Poland, it was later tracked at a number of wetland sites in Germany and France, continuously moving westwards. Although it now seems likely that the bird escaped or was released and has been journeying across Europe.

Dalmatian Pelicans by Rod Calbrade

Spring migration isn't over yet. Nightjar has just begun to arrive and Spotted Flycatcher should peak in the next week or so, weather permitting. There is also still plenty of time for it to be a Quail year; these wonderful little birds can arrive throughout May and June, and the latter half of May is also the time we would expect skua passage to peak. Arctic and Pomarine should be possible off all coasts, while those in western Cornwall, Ireland and north-west Scotland could also be lucky enough to see one or two sunning adult Long-tailed Skuas moving north.

As of this afternoon, a cold front is moving south through Britain bringing a return to cooler northerly winds to all areas over the weekend. However, a southerly or south-westerly airflow may resume from early next week which should bring a few more migrants with them. Red-footed Falcons numbers have been building steadily in central Europe in the past week and is one to look for on your local patch.

Paul Stancliffe and Stephen McAvoy 

Friday, 29 April 2016

Godwits on the move

The cold northerly winds that have been with us since last Saturday have reduced migration to trickle. The snowfall and freezing night time temperatures recorded in the last few days will also not have helped recently arrived migrants.

Summer plumaged Bar-tailed Godwit by Laurence Pitcher (Beachybirder)

Despite the poor weather, a few birds were still on the move, most notably Whimbrel and Bar-tailed Godwit. Small flocks of both were noted passing most coastal watchpoints last week and it is well worth keep an eye for summer-plumaged Bar-tailed Godwits if you are near the coast this weekend.



Bar-tailed Godwit reporting rate on Birdtrack showing peak in early May

Several surprising species were noted at watchpoints during the week, the most fascinating being a Nuthatch at Hilbre Bird Obs, Wirral on 23 April. This was only the third record for the island, with previous in 1962 and 2009, all in spring. Nuthatches are a very sedentary species with ringing data confirming that movements of more than 50 kilometres are exceptional. The most recent Atlas showed the species colonising northern England and southern Scotland, so could this species now be ready to jump the Irish Sea to colonise the Isle of Man and Ireland from where they are currently absent?

Nuthatch by Edwyn Anderton

Another surprise was a spate of Hawfinch records from the Scottish islands, with two on mainland Shetland, another on Fair Isle and one on the Outer Hebrides since last Friday. Very little is known about the movements of Hawfinches in Britain and Ireland, with some studies showing that birds breeding here make only limited movements. If that is the case, it seems likely that the birds seen in Scotland were heading back to Scandinavia or further afield.

Other notable migration counts occurred at opposite ends of the country: Fair Isle, Shetland logged 147 Wheatear and 244 Meadow Pipits on 27/4. In the far south of Britain, several hundred Willow Warblers arrived on Hengistbury Head and nearby Portland (both in Dorset) on the same day. Over 100 Blackcap also appeared on the latter site. Other sites throughout Britain noted only a handful of commoner migrants and the odd Lesser Whitethroat, Yellow Wagtail and Grasshopper Warbler. As predicted last week, the first Roseate Tern of the year was noted last Saturday in West Sussex and two days later the first was seen on their main British breeding colony of Coquet Island, Northumberland.

Reporting rate of Cuckoo


Looking ahead, it looks probable that temperatures could return to more seasonal levels from mid-week onwards and probably not a minute too soon for breeding and migrant birds alike. Given favourable conditions, there could be a good arrival of birds delayed by the northerly winds.

Paul Stancliffe and Stephen McAvoy

Friday, 22 April 2016

Spring has sprung, although a little reluctantly

Pretty much all of the long distance migrant species we would have expected to arrive in the UK by mid-April have done just that. But it still feels a little slow and that there are more individuals yet to arrive.

The good weather and associated easterly winds during the week produced some interesting movements of birds. Most notably, Monday and Tuesday produced some good counts of Wheatear at several sites, including 235 on Fair Isle, Shetland and 100+ on Bardsey, Gwynedd. Willow Warblers were also on the move on the same days with 500+ noted on the Isle of Portland, Devon and 200+ at Hengistbury Head, Dorset, with smaller counts at other sites.

Ring Ouzel by Neil Calbrade

After a slow start, Ring Ouzels were noted at many coastal and inland sites during the week, including seven on Bardsey. Spring migration of Ring Ouzel is reaching its peak in the next week or two and the species can turn up in gardens as well as coastal headlands. Listening out for their distinctive call is the best way to find your own Ring Ouzel on your local patch.

Reporting rate of Ring Ouzel on BirdTrack

Pied Flycatchers, Common Redstarts and Grasshopper Warblers were noted in single figures at migration sites along the south and west coast. It was slower going on the east coast, though Linnets seemed to be on the move with flocks of 50 to 100 birds reported.

Swifts have put in an early appearance with individual birds cropping up in several counties, with two birds making it as far north as Yorkshire and Lancashire.

Going up - reporting rate of Swift on BirdTrack this year


Around twenty Cuckoos have also been reported across the country, most from southern counties, but with at least one bird being seen Yorkshire. The first of the BTO's satellite tagged Cuckoos has also made it back safely. Stanley, tagged at Cranwich Heath, Norfolk in May 2014 arrived in Somerset near the town of Chard on the morning of 20 April.

Along the coast, Bar-tailed Godwit and Curlew have been on the move, with Little, Common and Arctic Terns reported as well. It is only a matter of time before Britain and Ireland's rarest seabird, the Roseate Tern, arrives back as well.

Roseate Tern by Stephen McAvoy

Chiffchaff and Blackcap are now being heard across the country but even these two species, for which migration is now getting a little late, still seem a little thin on the ground. It could well be that birds are being held up by weather fronts south in Europe, with the occasional window in the weather letting them through. Perhaps the next flow of warm southerly winds will see a huge arrival of birds all at once.

Unfortunately, the current indication is that northerly winds and cooler conditions will remain in place over the weekend and potentially well into next week. It will be interesting to see how this will impact our recently arrived migrants and residents such as Collared Dove and Robin that are well into raising their first broods in many parts of the country.

Collared Doves by Stephen McAvoy

Finally, we mentioned the beginning of an influx of Alpine Accentors into northern Europe in our last Migration blog update. As luck would have it, one Alpine Accentor did reach our shores with one spotted for all of five minutes in Hampshire on the 14 April. More Alpine Accentors were spotted in out of range areas in France, northern Germany, the Netherlands and two even reached Sweden. 

At the same time, two more species were recorded well out of range. Snowfinches, another high alpine specialist, began to be seen in similar areas to the Alpine Accentors with over 20 birds noted, including one on the island of Heligoland in the North Sea. Switzerland and southern Germany also recorded a very unusual influx of Western Subalpine Warblers in the last week, with more than 20 birds recorded so far. At least two of the latter have also reached Britain (both on Portland) so far this spring.

In the absence of any significant weather patterns in the Alps at the time, it seems likely all three species "overshot" their migration destinations in the southern and central Alps and continued much further north than usual, settling in any suitable habitat.

Paul Stancliffe and Stephen McAvoy

Friday, 8 April 2016

Spring has (sort of) sprung

The warm southerly airflow over the last few days did result in an arrival of summer migrants, with most of the early season birds well represented. However, the floodgates haven't quite opened yet.

Most notable was the first flush of Common Redstarts, Willow Warblers, Blackcaps and Grasshopper Warblers. Whilst quite a few Ospreys are back on their breeding grounds, with one pair at Rutland having already laid their first egg, others continue to arrive along the south coast. The first Reed and Sedge Warblers were also reported. Chiffchaff have arrived back and are well represented on complete lists submitted to BirdTrack.

Reporting rate of Chiffchaff this week on BirdTrack.

Common, Sandwich and Arctic Tern numbers have begun to build a little, and where there are terns, skuas are not far behind. Several south coast seawatches produced dark and light-phase Arctic Skuas.

A handful of early Common Swifts have also been reported, but overshooting southern breeders continue to be thin on the ground. The highlight was a single Woodchat Shrike in Cornwall, as well as a handful of Serin, Hoopoe and Wryneck. One of the latter ringed at Portland Bird Observatory aptly demonstrated the origin of its name.

Common Swift by Dennis Atherton/BTO


Hirundines have continued to arrive and are now being reported from most areas in the country. The first House and Sand Martins have even managed to reach Fair Isle in Shetland during the week.

Outgoing migrants have also taken advantage of the southerly airflow and numbers continue to fall. Brent Geese have been reported heading past east coast watchpoints along with Red-throated Divers and Common Scoters. Several of the latter have been reported from inland sites, including a female on a small lake in central London. Redwings and Fieldfares are beginning to feel decidely thin on the ground.

Reporting rate this year of Redwing on BirdTrack


The forecast for the next few days is currently very mixed, with cool north-westerly winds alternating with milder south-westerly winds. The latter may herald another strong arrival of migrants.

The rare bird to watch for this weekend is Alpine Accentor. It has been recorded only five times in Britain since 2000, with all sightings from the south and east coast. Prior to that, the species has been found in south Wales and even as far north as Fair Isle. Alpine Accentors appear to be on the move at the moment, with several birds recorded well away from their normal range in the montane regions of Europe. This included one flock of twenty birds near Frankfurt since Wednesday, as well as one in the Netherlands.

Paul Stancliffe & Stephen McAvoy

Friday, 1 April 2016

Migration getting started at last


Migration has been slow going until last weekend, but things have noticeably picked up since then with a change in wind direction. Chiffchaff, Wheatear, Sand Martin and Swallow were much more in evidence around the country and the first Reed, Sedge and Willow Warblers arrived.

Pipits were on the move as well. Spurn, Yorkshire recorded 357 Meadow Pipits on 30 March and 300+ moved through Portland, Dorset on the same day. On the west coast, 100+ were counted daily on Bardsey, Gwynedd the past week.

Firecrest by Graham Clarke

The highlight of the week was a big arrival of Firecrests along the south coast, with 101 counted at Dungeness, Kent on the 26 March. This local record tally was beaten just four days later with an amazing 120 Firecrests on site. A handful of other sites reached double-figures and the species was noted at many coastal watchpoints.

Reporting rate of Firecrest on Birdtrack

The south-westerly winds during the week also gave returning winter visitors a helping hand. Brent Geese were noted moving east off Portland, while Redwing and Fieldfare have also been on the move. Surprisingly few Ring Ouzels have been reported so far, but counts should pick up later this month.

There has been a distinct dearth of rarer spring migrants with only a few unconfirmed reports of Alpine Swift. Likely candidates to look for this week include Hoopoe, Woodchat Shrike and potentially a rarer warbler such as Sardinian.

Woodchat Shrike by Stephen McAvoy

The forecast for the next few days shows more southerly winds which would help migrants cross the Channel and the North Sea. However, from the middle of next the week there is a potential return to cool north-westerly winds which could migration on hold again.

Paul Stancliffe and Stephen McAvoy

Thursday, 24 March 2016

The floodgates are ajar

The cold northerly airflow has been holding things up during the last week but with lighter winds during the last couple of days some birds have managed to get through.

Several sites along the south coast have enjoyed double figure arrivals of Wheatear. Portland, Dorset seems to have seen the best of this with 60 being counted there on the morning of 22 March. Sand Martins have continued to trickle in but numbers remain small, similarly Swallows have been arriving but are still very thin on the ground, and one or two more House Martins have also been seen.

 
Sand Martin reports via BirdTrack

Garganey arrived in small numbers but on a broad front with birds being reported from several counties during the week. The largest movements seen this week involved Meadow Pipits arriving and then moving along the south coast. Several hundred birds were noted moving through on a couple of days.

Late arriving: Wheatear

As one set of birds arrives, another set is departing. Redwing and Fieldfare have been recorded, at times in quite large flocks, as were flocks of migrating Starling. Geese were on the move as well, with northward bound Pink-footed Geese amongst others noted in Scotland. Woodcock were found at several coastal sites.

Redwing moving through

The most intriguing migrant this week was probably the Blue Tit trapped at Sandwich Bay Bird Observatory. It was found to have been ringed in Lithuania and had good muscle and fat scores, presumably to fuel the outgoing migration back north and east. Keep an eye on the BTO's Demog blog on this and other ringing related stories.

The Met Office surface pressure charts show potential for some south to south west winds extending from northern Spain across France to southern Britain from Friday onwards. This ought to result in a fresh wave of arrivals from the south, and allow any migrants wanting to attempt the crossing of the North Sea to have a go.

Likely new arrivals next week include the first Willow Warblers and Blackcaps, as well as more Wheatears and Sand Martins. Given the stormy weather conditions, there may even be local "falls" of migrants. Rarer migrants to keep an eye out for in late March and early April include Purple Heron, Alpine Swift and the even rarer Great Spotted Cuckoo!


Purple Heron (Graham Catley)

 Paul Stancliffe and Stephen McAvoy