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, 30 September 2016

East meets West

It has been an exciting week with new arrivals from the east and west this week. Top billing goes to the Eastern Kingbird found on Barra in the Outer Hebrides on Thursday. This large flycatcher is a widespread breeding bird in Canada and the US and has been previously found twice in Ireland following sustained westerly winds. The Kingbird joined an impressive cast of birds from North America found during the week: two Swainson's Thrushes, four Red-eyed Vireos and singles of Yellow-billed Cuckoo and Rose-breasted Grosbeak.

Red-eyed Vireo by Luke Delve

Arriving from the opposite direction, birds of Scandinavian and Siberian origin continued to arrive despite the prevailing westerly winds. The Yellow-browed Warbler invasion slowed to a trickle, with only single figure counts from coastal watchpoints. However, a few more were noted away from the coast, including one at the BTO's Nunnery Lakes reserve.

Yellow-browed Warbler at the Nunnery Lakes by Neil Calbrade

In terms of more widespread migrants, 1,450 Swallows passed Christchurch Harbour, Dorset during the week and there were counts of several hundred birds from other migration watchpoints. While a handful of House Martins are still feeding young in nests, the majority are on the move south and over 1,000 were counted moving past Filey, East Yorkshire. Pink-footed Geese arrived in numbers this week and the count of 2,000+ passing Spurn, East Yorkshire was the highest noted on the east coast this week. Several sites reported increased numbers of Goldcrest and the species should reach a peak later next month.

Reporting rate of Goldcrest on BirdTrack

All but one of the active tagged BTO Cuckoos have crossed the Sahara and are currently spread between Niger and Chad. Cuckoo "Larry" has jumped ahead of the rest and has reached the Republic of Congo. As of this morning, Cuckoo "Jack" is still in southernmost Italy, but looks set to make the perilous crossing any day soon.

Current location of the BTO-tagged Cuckoos

The south-westerly airflow looks likely to remain in place over western Britain and Ireland into early next week and could well drop another North American rarity or two onto western headlands. A weak low pressure system moving through the Channel on Saturday could bring some north-easterly winds to eastern Britain for Sunday and Monday. This could result in another wave of Yellow-browed Warblers arriving here, as well as winter thrushes. Surprisingly few Ring Ouzels have been reported so far this autumn so that is one bird to look for this weekend on the east coast.

One to look for this weekend - Ring Ouzel by John Proudlock/BTO

Rarer passerines may also make an appearance, and such after species as White's Thrush, Red-flanked Bluetail and Red-throated Pipit all having a track record of making appearance at this time of year. All this makes for an interesting mix of birds on the move and well worth going out no matter which part of the country you are in.

Stephen McAvoy

Friday, 23 September 2016

Yellow-browed Warbler Invasion

The migration story of the week was the remarkable arrival of Yellow-browed Warblers on Flamborough Head, East Yorkshire on Wednesday, with a minimum of 139 recorded during the day. A narrow band of north-easterly wind across the North Sea appears to have funnelled the warblers onto the headland of Flamborough.

There have been plenty of reports elsewhere in Britain, though for the moment, the majority are being noted along the east coast of Britain. In the weeks ahead, the birds should begin to filter south and west, and with more records inland in recent years, there is a chance you may find one on your patch even if you are not near a prime coastal migration site.

Yellow-browed Warbler by Stephen McAvoy

The arrival of Yellow-browed Warblers in the last few days is also reflected on the reporting rate on BirdTrack:

Commoner migrants have also been on the move, with Pink-footed and Brent Geese beginning to arrive in numbers. Meadow Pipits continue to move through, with over 1,000 logged at Christchurch Harbour, Dorset on Wednesday, and 1,200+ at Sandwich Bay, Kent on Monday. Several sites also reported good 100+ counts of Blackcap and Chiffchaff during the week. The 484 Snipe recorded on North Ronaldsay, Orkney on Thursday would have also made a very interesting sight!

Snipe by Liz Cutting/BTO

Looking ahead, the weather looks set to be dominated by westerly airflow, so there is a chance a Nearctic warbler or vireo could make an appearance on a headland or island in Ireland or western Britain. The first Ring Ouzels should also start to arrive at migration points fairly soon, as should the first returning Redwing and Fieldfare.

Ring Ouzel by Paul Hillion/BTO

Paul Stancliffe and Stephen McAvoy

Friday, 16 September 2016

Arrivals and Departures

Bird migration is in full swing as we move into late September and there were some notable counts of some commoner migrants this week despite the generally poor conditions for finding birds.

Wheatear by Mark Johnson (via #Birdtrack Flickrpool)

The obvious migration highlight of the week was the (very lost) Cory's Shearwater seen flying over Regent's Park in London during the week. Small numbers of shearwaters are recorded at inland locations in late summer and early autumn, in many cases recently fledged youngsters that have become disorientated. Large shearwaters such as Cory's or Great are significantly rarer inland and are usually found in the aftermath of particularly strong storms.

Lapland Bunting by Janice Sutton (via #BirdTrack Flickrpool)

Notable scarcer migrants on the move included Lapland Bunting, with up flocks of up to 90 birds reported from western Scotland and Ireland in recent days. A handful have also been reported in southern Britain so it is well worth listening out for their distinctive calls when out and about. The first Yellow-browed Warblers of the autumn have also arrived, hopefully heralding yet another bumper year of these charming Siberian sprites.

Yellow-browed Warbler by Stephen McAvoy

Significant counts of commoner migrants included 3,500 Swallows noted passing Christchurch Harbour, Dorset on the 14th September and just under 3,000 at Skomer, Pembrokeshire on the same day. Fair Isle, Shetland logged 232 Wheatears on the same day, with 150 Wheatears counted on Portland, Dorset the next day.

The Migration Festival at Spurn, East Yorkshire ended with a fantastic movement of over 4000 Meadow Pipits passing through on the Sunday, though the highlight of the weekend was undoubtedly the Kentish Plover found the previous day. A worthwhile event for anyone with an interest in bird migration so keep a space in your diary for MigFest 2017!

Stephen McAvoy

Monday, 11 July 2016

Early movers

Although autumn is still some way off, migration is already in full swing with Cuckoo, seabirds and waders amongst others on the move. All of the BTO GPS-tagged Cuckoos have moved south and out of Britain. One of the tagged birds has already crossed the Sahara and is now in central Mali. The BirdTrack graph shows the drop off in recent records.

Reporting rate for Cuckoo

Juvenile Cuckoos will still be present into August and September before they too will depart to their winter quarters.

Cuckoo by Neil Calbrade

Seabirds are also on the move with the first Great and Cory's Shearwaters reported from seawatching sites in southern Britain and Ireland. Breeding in the South Atlantic, Great Shearwaters migrate north in spring (their autumn), spending the early summer off the east coast of North America. In July and August, they head south again, but on a more easterly track, passing western Europe and Africa. Strong winds, especially from the west or south-west, can push these highly oceanic birds closer to land, sometimes in spectacular numbers.

Great Shearwaters by Hannah Keogh (via the #Birdtrack Flickrpool)

Further coastal birds on the move included Arctic and Great Skuas, while small flocks of Common Scoters were noted passing coastal watchpoints in the last week. Looking ahead, the weather forecast is mainly for westerly winds and showers, conditions that look quite suitable for pushing skuas, shearwaters and other seabirds closer to shore.

Migrant gulls have also started arriving, including the first juvenile Yellow-legged and Mediterranean Gulls. One of the latter on Fair Isle last week was only the second record for this remote island.

Mediterranean Gull by Stephen McAvoy

While the long-staying Great Knot in Norfolk got a lot of attention, other waders have been on the move. Green and Wood Sandpipers have been arriving, and a flock of 100 Curlews flew south past Landguard Bird Obs, Suffolk. Numbers of other arctic breeding waders will continue to build as adults and the first juveniles arrive in the coming weeks.

Finally, the first migrant Wheatear, Whinchat and Common Redstarts have been reported and 228 Sand Martins were seen moving south at Spurn, East Yorkshire on the 4th of July.

Paul Stancliffe and Stephen McAvoy

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