With migration pretty much over (it never truly stops altogether) now is a good time to reflect on what kind of a migration season it has been.
The most obvious feature has been the weather. Migrant birds heading back to the UK from their winter in Africa and southern Europe have had to battle against some horrific conditions. Strong winds, heavy rain, hail and even snow have all featured and less than ideal conditions have dominated pretty much throughout the migration period.

So, what effect has this had on our summer visitors? The first and most obvious effect was to delay the arrival of a number of them, as evidenced by the BirdTrack reporting rates. Whitethroat and Lesser Whitethroat illustrate this well.

Initially it looked like the numbers of many of our summer migrants were going to be quite low this year, and indeed early evidence for Swallow, Swift and House Martin suggest that this might be the case. However, it is interesting to note that Portland Bird Observatory, Dorset have had one of their best springs for numbers of common migrants for many years. At Portland, Whitethroat and Lesser Whitethroat showed an increase of 138% and 137% above the 2007-11 average. The BirdTrack results also indicate that both of these species are at or near their normal levels.

It is too early to know for sure whether there are fewer birds here or not. We will have to wait until later in the year when all of the data that BTO volunteers collect through surveys such as the Breeding Bird Survey, the Constant Effort Ringing Scheme, BirdTrack and the Nest Record Scheme has been analysed to know how out birds coped with a very abnormal spring and early summer.

Anyone can take part in these surveys and help contribute to the bigger picture. For more information, please visit the survey pages on the BTO website.

A far from normal spring

It has been anything but a normal spring. March, with its early spring Mediterranean overshoots, at times felt like May. April, with its heavy rain, snow and hail, resembled November, and so far May has felt very unspring-like.

Swallows and House Martins sheltering from the Rain

in Mevagissey, Cornwall, by David Jackson. May 2012

What effect has this had on our migrant birds?

March 2012 became the third warmest March on record, with temperatures often exceeding those in southern Europe.  As a consequence, early March saw higher than average arrivals, for the time of the year, of Wheatears and Swallows. As the month progressed and the temperatures held, it felt more and more like southern Europe and the arrival of over thirty Hoopoes, a couple of Purple Herons, Baillon’s Crake, Woodchat Shrike and Scops Owl only served to reinforce this.

Just as it seemed like spring migration was about to step up a gear the weather turned. April will be remembered as one of the wettest on record, overturning drought warnings in some counties to flood warnings. It wasn’t only in the UK that this weather pattern dominated, southern Europe suffered too.  On 16 April, the mid-morning temperature at Aiguamolls de L’Emporda, northern Spain, was 5 degrees, forcing migrating Swallows to seek shelter in the hides of the nature reserve.

Swallows at Aiguamolls de L'Emporda by Rod Leslie

Further south, gale force winds whipped up huge sandstorms over the northern Sahara and out into the southern Mediterranean Sea, forcing migrants into the water and providing a bonanza for feeding Lesser Black-backed Gulls. The March rush slowed down as rapidly as it had begun, and many of our migrants began to look like they were going to be late back this year. Whitethroats didn’t start to arrive in earnest until late April/early May, two to three weeks later than the norm.

BirdTrack results show that it was a similar pattern for several other species that normally arrive in mid-April, notably Hobby, Cuckoo, Turtle Dove and warblers including Grasshopper, Reed, Sedge and Garden Warblers. BirdTrack reporting rates for all these species are striking, as are those of both Whitethroat and Lesser Whitethroat.

Hobby by Jill Pakenham

So, here we are, mid-May and the weather is decidedly cool and wet. The winds are in the main coming from the north, and for the most part are quite strong. Even though most of our summer migrants are now represented, there are parts of the country in which many are still to arrive. When conditions allow, there are still some impressive movements of birds at coastal watchpoints, so migration is far from over yet and will almost certainly still have some surprises up its sleeve.

This coming weekend the northerly winds are due to turn more southerly, then south-easterly and eventually easterly. If this is the case, migration watchers on the east coast could be in for a bonanza, and as we are moving into the latter half of May, anything could turn up. I know that I’ll be out in search of a Red-footed Falcon or two.

Migration slows a little.

With the mass arrival of many of our common migrants last week, Whitethroats, Garden Warblers, Swifts and Swallows poured in, it is hardly surprising that this week has been a little slower. That said, migration has been steady, with more Swifts, Swallows and House Martins arriving, along with Spotted Flycatchers, Turtle Doves and the first Nightjars.

Nightjar by Neil Calbrade

It has been the rarities that have grabbed the headlines, with both Calandra and Crested Larks turning up, both in Kent. At least three Pallid Harriers graced the east coast and, what continues to be one of the best springs for a long time for Black-winged Stilt continued with the appearance of four birds together in Kent. Red-rumped Swallows reached double figures, with at least fourteen birds being found, from the Isles of Scilly to North Yorkshire.

Will it be a good weekend for migrants?


It looks like it is going to be a largely dry but windy weekend. The wind will come from the north and north west on Saturday, dropping during the afternoon, and turning south westerly overnight and through to Sunday morning, only to increase in strength again. So, it looks like Sunday morning might be the best time to be out watching visible migration, or in search of grounded migrants.It is hard to say what might turn up. The light northerlies of Saturday afternoon and evening might coax something like a Great Reed Warbler this far north.

The floodgates open

As soon as the wind turned south-easterly and dropped they began to arrive in their hundreds and thousands. Many sites had their largest falls of the spring so far and some hinted at their largest falls ever, but what was sure was that the migrant floodgates opened at last.

As the week progressed the wind turned northerly but for the most part remained light, perfect conditions to observe visible migration. At Portland Bill, Dorset over 10,000 Swallows were estimated to have flown through on the 3 May, whilst in previous days there were at times too many to count.

On the Isles of Scilly, flocks of warblers, largely Blackcaps and Willow Warblers but also containing Garden Warblers and Common Whitethroats, were seemingly everywhere. This is reflected nicely in the BirdTrack reporting rate.

Common Whitethroat by Amy Lewis

With Swifts and Spotted Flycatchers also making it back, the first Nightjar won’t be too far behind them. Two of the BTO satellite tagged Cuckoo’s also took advantage of the weather and arrived back in the UK after spending the winter in the Congo Rainforest, for more information and to see their full migration routes.

Cuckoo by Steve Ashton

Southern overshoots have also been well represented. Five new Cattle Egrets arrived, along with the first Squacco Heron of the year, five Black Kites, three Short-toed Larks and at least seven Red-rumped Swallows. Whilst from the east a Citrine Wagtail and Red-breasted Flycatcher were found in Norfolk, and a Black-winged Pratincole arrived in Cheshire.

The wind is due to stay in the north-east and remain fairly light throughout the weekend, turning southerly on Monday, perfect conditions for further arrivals of common migrants and vagrants from the south and east. So if you haven’t heard a Cuckoo this weekend could be the time to get out and listen, and if you do hear one you can support the BTO Cuckoo project by texting a donation to CKOO12 £2/£5/£10 to 70070, and  if you’re out looking for vagrants, a Rock Thrush might just be on the cards.

North and west, east and south divide.

It has very much been a week in which migration has been a game of two halves, with south and east coast watchpoints having had a fairly quiet time as far as visible migration and grounded migrants are concerned.  In contrast, during the early part of the week, Fair Isle, Shetland, and Bardsey, Gwynedd, had their busiest days of the spring so far.

Some birds have been getting through the heavy rainstorms south of the UK. In the south, more Nightingales arrived back on territory, birds could be heard throughout southern Britain. Cuckoos continued to trickle in, along with a small number of Whitethroats and Grasshopper Warblers. Hirundines continued to arrive too but the numbers for the time of the year are low. Seawatchers in the south did experience a good passage of Great and Arctic Skuas, along with a small number of Pomarine Skuas. Arctic Terns were also still much in evidence and were joined at many sites by Little Gulls and the odd Black Tern.

Pomarine Skua by Joe Pender

Migration in the north and the west has been much more in evidence. At the beginning of the week a large number of Robins, Dunnocks, Song Thrushes and Ring Ouzels arrived on Fair Isle, along with three Tree Pipits, a Blue Headed Wagtail, ninety-one Wheatears, four Swallows, Two Wrynecks and singles of Hoopoe and Common Crane. At the same time Bardsey was teeming with migrants, which included over two-hundred Willow Warblers, over one-hundred Swallows, around eighty Blackcaps and eleven Grasshopper Warblers.

Wryneck by Jill Pakenham

Wales also held the lion’s share of southern European migrants. A Little Bittern was found in Pembrokeshire, Ceredigion hosted a Kentish Plover and six White Storks were seen over Colwyn Bay.

It is interesting to look at the distribution of migrants this week and relate them to the weather we have been experiencing. The birds that arrived on Fair Isle did so when the wind turned east/south-easterly, and those on Bardsey when the wind was from the north.

 It could be that these migrants drifted east in the westerly airflow that southern Europe have been experiencing as weather fronts arrived from the Atlantic. Having drifted east it is likely that they then made their way north on the wrong side of the North Sea, the weather here has been more settled at times. 

As they made their way north the anti-cyclonic weather fronts would find them in a more easterly airflow and by utilising this they would make their way back across the North Sea to the UK, arriving much further north than they might have been aiming for. This might help to explain a busy north and a quiet south migration-wise this week.

Looking at the weather forecast for this weekend, Saturday morning looks like the time to be out and about in search of migrants, as the winds south of the UK will be lighter than they have been for a week or so. By Saturday afternoon a low pressure system is due to cross central France, bringing heavy rain and fairly strong winds with it. It could be that Sunday will see a repeat performance of earlier in the week with the north and west again being the place to be.

Arctic Terns aplenty.

Even though the weather has been challenging for northward bound migrants, particularly in southern Europe, small numbers have still trickled in in during the week, with the exception of Ring Ouzel and Arctic Tern, which arrived in force.

Arctic Tern by Andy Mason

The early part of the week saw the continued Ring Ouzel arrival but as it tailed off towards the middle of the week, Arctic Terns took over. Flocks of this marine tern were seen migrating through the Midlands, with one flock of eighty birds lingering on Wednesday afternoon at Attenborough Nature Reserve, Nottinghamshire. Accompanying these were a small number of Little Gulls and the first Black Terns of the spring.

Arctic and Common Tern can be difficult to separate. See the BTO identification video for some useful tips.

As expected, most of the migrant action has been in the south, however Fair Isle, Shetland, saw its first Swallow and Tree Pipit of the spring.

Two Turtle Doves were found in Cambridgeshire, a few Whitethroats arrived and Reed Warblers can be heard in most southern reedbeds, albeit still in small numbers.

Despite the north and westerly airflow and very stormmy weather around the Mediterranean, southern overshoots have been well represented this week. With a Kentish Plover, Little Bittern and Black Kite, Wales was the place to be. Five new Hoopoes were found in southern Britain, along with two more Black kites, in Devon and Hertfordshire, and the two Black-winged Stilts from last week still putting in appearances.

Black-winged Stilt by Neil Calbrade

Common Sandpipers also put in an appearance with small groups seen at a few south coast sites. In general though it has been a fairly quiet week for the time of the year. However, it looks like there might be a small window in the weather in Europe on Saturday afternoon/Sunday morning, which could  open the floodgates for those birds that are held-up further south, before stormy Atlantic weather returns on Monday to perhaps close them again.

Ring Ouzels arrive in force

This weekend’s cold north-easterly airflow wasn’t ideal for summer migrants heading back to the UK. However, birds did arrive, with Ring Ouzel being the most notable. Most of these were seen in the south but birds reached as far north as Glen Strathfarrar, Highland. In several counties flocks of Ring Ouzels reached into double figures, with fourteen being seen together at Pegsdon, Beds. This arrival is reflected nicely in the BirdTrack reporting rate.

Ring Ouzel by Tommy Holden

At this time of the year, Ring Ouzels can turn up on migration almost anywhere. Check-out the latest BTO identification video to listen to the differences between Ring Ouzel and Blackbird song, and other tips on identifying this enigmatic thrush.

South coast visible migration watchers were also rewarded with a steady arrival of Swallows and Willow Warblers, whilst smaller numbers of Redstarts, Yellow Wagtails and Grasshopper Warblers also made landfall. Some migrants are being held-up though, as illustrated in an email we received from Rod Leslie in the Pyrenees

"I was at Aiguamolls de l'Emporda just south of the Pyrenees yesterday (16 April) in a howling westerly gale & temperatures down to 5 degrees C. Migrants completely pinned down with large flocks of Hirundines looking very tired. In several hides where leeward windows had been left open large numbers of Swallows were sheltering - see the attached photo. They were so tired it was possible to quietly share the hide with them."

Hide full of sheltering Swallows

Aiguamolls de l'Emporda

The first multiple arrival of Nightingale was also obvious, with five singing males together in one Hampshire woodland. This spring the BTO is conducting a Nightingale survey to map all singing males.

With northerly winds dominating it is hardly surprising that Mediterranean overshoots were thin on the ground. However, at least two Hoopoes were reported, in Norfolk and Worcestershire, and two Black-winged Stilts braved the unseasonable spring chill in Dorset and Lincolnshire.

Migration across the North Sea finally got underway. Stephen Menzie reports.

Wind, rain and cool weather had put a dampener on migration at Falsterbo over the previous week or so. The last 5 days have seen a change in the weather — southeasterly winds and warmer temperatures — and with the change in weather has come a wave of migrating birds. Robins are still the most obvious (we ringed 250 on Saturday) but we've also trapped our first trans-Saharan migrants; our first Willow Warbler on Thursday and our first Lesser Whitethroat on Sunday. Moreover, we finally got our first (and so far only) Blackcap of the spring.

Lesser Whitethroat by Stephen Menzie

Swallows, Wheatears, Ring Ouzels, Tree Pipits and Ospreys have all been seen with increasing frequency over the last few days. Falsterbo has already hosted a male Redstart — an early bird by Swedish standards. Sandwich Terns have become a constant background presence as they pass along the shore close to the lighthouse. Sunday saw a Pallid Harrier passing over the peninsular — one of the birds seen here last autumn on its way back north?

Scarce short-distance migrants ringed in the lighthouse garden have included a Hawfinch and several Firecrests (it's been an exceptionally good spring for Firecrests here in southern Sweden). 3,000 Eiders passing Sweden's most southerly point was a spectacle worth seeing — migration in action!

For more see Stephen's blog.