BTO - British Trust for Ornithology - Migration

Cuckoo Tracking Project

WILLIAMSKELLORN — Thu, 25 Oct 2018 10:17:22 +0000

The Cuckoo Tracking Project has been revealing new discoveries about how British Cuckoos migrate, and the challenges they face. Follow and support this ground-breaking project.

Friday, April 1, 2011 - 00:00

Help us follow Cuckoos on migration and discover why they are in decline

We’ve been satellite-tracking Cuckoos since 2011 to find out why they are in decline:

Since 1995, the number of Cuckoos has decreased by over 30%.
The Cuckoo is currently Red-listed as a Bird of Conservation Concern in the UK.
Support this project by sponsoring a Cuckoo >

Progress so far

We’ve learned lots of vital information, such as how the different migration routes are linked to declines, and some of the pressures Cuckoos face whilst on migration, but there is still much more to discover.

We have been able to share our expertise around tracking Cuckoos with other international studies, such as the Beijing Cuckoo Project.
Read more about our Cuckoo Tracking Project.

What’s next

We now need to look more closely at how dependent Cuckoos are on, and how much their migration is linked to, the drought-busting rains of the weather frontal system known as the Inter Tropical Convergence Zone (ITCZ) as they move out of the Congo rainforest and begin to head back to the UK via West Africa.

Our Cuckoo Tracking Project is vital and it wouldn’t be possible without the amazing support from funders and sponsors.

Sponsor a Cuckoo

Watch the Cuckoos migrate on our map

Each Cuckoo’s tag sends us location data approximately every day, so we can follow them and learn more about their migration.

Track our Cuckoos as they migrate

Chris Hewson

5/11 - First round of five Cuckoos tagged, wintering sites in the Congo identified
3/12 - Different routes discovered on return journeys
2016 - First scientific paper published on on the routes of our Cuckoos

Spend as much time as you like following each Cuckoo's migration on the map below - use the controls to animate or step through their movements. No technical skills are required to support this project - just a love of Cuckoos.

Cuckoo declines linked to different migration routes to Africa

ongoing Farmland birdsWoodland birds funding Yes cuckoos@bto.org

Travel far, breed hard, die young! The surprising lifestyle choices of Short-eared Owls

MIKETOMS — Tue, 16 Jan 2024 08:53:47 +0000

2024-02 16 Jan 2024

'Travel far, breed hard, die young' – while this might sound like a hedonistic rock-and-roll lifestyle, a new study by researchers at the British Trust for Ornithology (BTO), with collaborators in Iceland and Spain, reveals this is how Short-eared Owls live their lives. Describing the incredible and surprising movements of Short-eared Owls across Europe and south into Africa, these new results underline a need to plan conservation action for this species at larger scales than previously considered.

The Short-eared Owl, whose appearance and disappearance from regions has fascinated birdwatchers and ecologists for decades, was a bird for which we lacked key information on movements and the degree of connectivity between populations. A new study by BTO researchers, along with the University of Iceland and the Spanish National Research Council (CSIC), just published in the journal Ibis, fills this important knowledge gap and provides new evidence that will enable us to better protect and conserve this enigmatic species.

The Short-eared Owl has an extensive, but declining, distribution, across which it is predominantly a specialist predator of small mammals. The abundance of its favoured vole prey can vary markedly, both in time and space, making these rodents an unpredictable food resource. While Short-eared Owls can switch to other prey when voles are not available, their more common response is to move to other areas, resulting in irruptive or nomadic movements. Studying these movements has proved challenging, but advances in tracking technologies have enabled BTO Senior Research Ecologist John Calladine and colleagues to collect new information.

The movements of 47 Short-eared Owls, from multiple European locations (Iceland, Scotland, and Spain), were tracked with GPS devices. The study reveals an unexpectedly large degree of movement in the tracked individuals, with some of the birds tagged in Scotland and Spain travelling widely across Europe and North Africa, and one bird tagged in Iceland travelling to Britain. Nine individuals of these 47 were monitored while nesting over two seasons, and the distances between nest sites used by the same individuals in sequential years ranged from 41 to 4,216 km. As far as we are aware, these represent some of the longest known distances between nest sites by any bird.

Of two females tagged while nesting just 2 km apart on the Isle of Arran (Scotland) in 2021, one went on to breed in northern Norway in 2022 and the other to the Pechora Delta in Arctic Russia. Incredibly, another female tagged at its nest in Scotland in 2017 – bred twice in 2018, once in Scotland and again in Norway. However, travelling so widely to find places where there is sufficient prey where large broods can be reared does have its consequences – less than half the adult birds survive from one year to the next.

So, rather than leading a hedonistic lifestyle, these birds are actually behaving selflessly. Their extensive travel to find enough voles to rear the next generation of owls has a knock-on effect on the condition of the individual and its chances of surviving for another year.

Out of 18 successful breeding attempts by 14 tagged females, in all but two instances the females departed before the youngest chick was fully independent, leaving the male to finish rearing the brood. Again, this is new information that was not even suspected before this study.

The types of movements recorded in this study, and the scale of these, implies that there are not distinctly separate populations of Short-eared Owls across much of Europe. Rather, there is a single potentially integrated population across most of the range, albeit with some comparatively more – but not completely – isolated populations (such as that in Iceland).

John Calladine, BTO and lead author on the research paper, said "This new knowledge has significant implications for attempts to protect and conserve this species, and underlines a need to collect information on Short-eared Owl populations from sufficiently wide geographic scales and/or over the long term. Importantly, conservation action for the birds will need to be on a similarly wide scale."

John continued "This study was only possible because of the generosity of those individuals and organisations who provided the funding necessary to purchase and deploy the tracking devices fitted to these amazing birds."

Neil Morrison, of the Tay Ringing Group and who has been key to the study right from its conception, said "I've been studying these owls for decades and thought I knew what they did. How wrong could I have been! To think that owls breeding in 'my glens' could then go on to breed in the Arctic or try and cross the Sahara –, who would have thought that! It's been a real privilege to be able to follow these birds in such detail. Now we have the knowledge to help ensure they continue to amaze us into the future."

Publication details

The paper detailing this new work is:

Calladine, J., Hallgrimsson, G.T., Morrison, N., Southall, C., Gunnarsson, H., Jubete, F., Sergio, F. & Mougeot, F. (2024). Remote tracking unveils intercontinental movements of nomadic Short-eared Owls Asio flammeus with implications for resource tracking by irruptive specialist predators. Ibis https://onlinelibrary.wiley.com/doi/full/10.1111/ibi.13304.

Please email press [at] bto.org for a copy of the paper for media use.

Images

Images are available for use alongside this News Release. These can be downloaded from this link for which you will need to enter the password: sheow_2402

Alternatively, please contact press [at] bto.org quoting reference 2024-02.

Further information

More information about the history of this work is available on our Short-eared Owl tracking project page.
Facts and figures about Short-eared Owl populations in the UK can be found on our Short-eared Owl BirdFacts page.
Learn more about the biology of the Short-eared Owl on our Project Owl pages.

Remote tracking unveils intercontinental movements of nomadic Short-eared Owls Asio flammeus with implications for resource tracking by irruptive specialist predators

MIKETOMS — Thu, 11 Jan 2024 11:35:54 +0000

The Cuckoo cohort of 2024 takes flight!

More Details

Calladine, J., Hallgrimsson, G.T., Morrison, N., Southall, C., Gunnarsson, H., Jubete, F., Sergio, F. & Mougeot, F. Ibis 10.1111/ibi.13304 Nomadic species can rely on unpredictable resources making them challenging to understand and, consequently, to conserve. Here, we present knowledge advancement for a nomadic predator, the Short-eared Owl Asio flammeus, by tracking individuals from a wide latitudinal range inclusive of most breeding populations in western Europe (Iceland, Scotland and Spain). Tracked owls showed pronounced plasticity in both inter- and intra-individual behaviour. Distances between sequential breeding areas of individual owls ranged from 41 to 4216 km, with similar low fidelity to areas used at other times of year. Owls spent most (> 60%) of their time occupying home-ranges (including breeding) and least (< 10%) undertaking long-distance movements. The propensity for long-distance movements was least for the most geographically isolated population, Iceland. Annual survival rates of 47% were lower than expected for an owl of comparable body mass with mortality concentrated during long-distance displacements and immediately after breeding. Extensive, nomadic travel to find areas where large broods might be reared may incur carry-over costs that lower survival. Conservation planning and assessment for nomadic species and their habitats must acknowledge the uncertainties associated with nomadism at scales from local to international. Funding and other support was from many individual donors, the Abertbrothock Skea Trust, AEB Trust, Arran Natural History Society, British Birds Charity, Callander SWT Group, DOPP (BirdLife Slovenia), Gilman Trust, the Henry Robb bequest, J & JR Wilson Trust, Loch Lomond Bird of Prey Centre, Muncaster Castle, NBI Ljubljana, Newstead Charity, Sound Approach, Stirling SOC Group, Tan International, Tayside Raptor Study Group, Tay Ringing Group, University of Iceland Research Fund, Landsvirkjun Energy Research Fund, the Migra Programme (SEO/Birdlife with funding from Fundacion Iberdrola Espana), the Government of Spain (BOOMRAT project, grant no. PDI2019-109327RB-I00), the Instituto Tecnologico Agrario de Castilla-y-Leon–Junta de Castilla-y-Leon, Diputacion Provincial de Palencia and Diputacion Provincial de Valladolid (GESINT-TOP Project); to all of whom we are most grateful. Changing migration patterns of the Short-eared Owl <em>Asio flammeus</em> in Europe: an analysis of ringing recoveriesSensitivities to land use change by breeding Short-eared Owl (<em>Asio flammeus</em>) in BritainTracking Short-eared Owls: Notes from the field

BirdTrack migration blog (winter 2023/24)

SCMAYSON — Fri, 08 Dec 2023 14:22:12 +0000

Winter is often regarded as the season when nature sleeps - but the cold months can be an excellent time for birding. No

Scott Mayson

BirdTrack Organiser

Scott’s role includes the day-to-day running of BirdTrack: updating the application, assisting county recorders by checking records and corresponding with observers.

Scott Mayson

BirdTrack

Migration

Goldeneye

On the sea

In November, a succession of storms brought torrential rain, flooding and strong winds to much of the UK. Storm Ciarán swept across the south coast of England then pushed eastwards up the English Channel and into the North Sea, rewarding those willing to brave the gale-force winds with a host of late autumn seabirds.

Grey Phalaropes, Little Gulls, and the occasional Sabine’s Gull were noted, but it was Leach’s Petrel that was on most people’s radar – and this species didn’t disappoint. Several sites along the south-eastern coast of Britain logged good numbers, with a count of 115 in East Sussex being topped by a huge tally of 203 further along the coast at Dungeness, Kent. This same site also recorded an amazing 84 Storm Petrels, making for a truly memorable day of seawatching.

The sea provided yet more birdwatching during November as divers continued to head south to their traditional wintering areas, often in sheltered bays. BirdTrack saw an increase in reports for both Black-throated and Great Northern Divers, with some individuals being found on some inland reservoirs and lakes in addition to the stream of birds seen offshore.

Waxwings

Waxwings have continued to grace berry bushes up and down the country, much to the delight of birders and non-birders alike.

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The 2023 BirdTrack reporting rate for Waxwing in Scotland (red) and England (blue) reflects the birds’ southward movement in recent weeks.

In early November, the bulk of the sightings came from Scotland as birds arrived from across the North Sea, but over the last few weeks, flocks have pushed further south and west in search of new berries on which to gorge themselves. The BirdTrack reporting rates for Scotland and England show this shift in occurrence nicely, with reports falling away in Scotland while increasing across England.

The Grampian Ringing Group has been running a Waxwing colour-ringing study for a number of years to help researchers understand how flocks move across the country, if they winter in the same locations each year, and whether the birds’ wintering locations correlate with particular breeding populations in Fennoscandia. Each bird is given a unique combination of coloured rings, so individuals can be identified in the field.

You can help the group with their studies by reporting any colour-ringed Waxwings that you see – in doing so, you will also find out when and where the bird you saw was ringed! You will need to make a note of the colour of any rings, as well as their position and which leg of the bird they are on – if you have a camera, photographs can be a useful reference for this.

Looking at Waxwing reports across the rest of Europe, there appears to be a similar influx occurring in eastern Poland as flocks filter south through Sweden, Denmark, and Germany. You can watch this movement on EuroBirdPortal. Here in the UK, we will need another spell of easterly winds before we see any further significant arrivals on this side of the North Sea.

Wildfowl, waders and gulls

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Prolonged periods of freezing temperatures across Europe can result in ducks such as Smew moving to Britain and Ireland in search of open water.

Wildfowl continued to arrive from across Europe, with numbers of White-fronted Geese, Pintails, Pochards and Goldeneyes building. Goosanders, Red-breasted Mergansers and the first few Smews also gave a real wintery feel to the end of November as they moved to established wintering areas. These three species are diving ducks, with fish being their main prey item – their serrated bills, supremely adapted to catching fish underwater, give rise to their colloquial epithet ‘sawbill’. While Goosanders and Smews have a preference for freshwater habitats, Red-breasted Mergansers can often be found either on the sea around shallow coasts or on estuaries.

Bewick’s Swan is typically one of the last winter visitors to arrive in Britain and Ireland, and the species has been arriving later and later in recent years. This winter has been no different; the first arrival occurred in mid November, some 10–14 days later than the historical average. Studies have shown that this is in part due to birds ‘short-stopping’ on their migration, travelling less far south and west as climate change increases winter temperatures across northern Europe. You can read more about this phenomenon in the Waterbirds in the UK article ‘Short-stopping unwrapped’.

Short-stopping is partly responsible for the huge decline in the UK’s wintering population of Bewick’s Swan, which fell by 95% between the winters of 1995/96 and 2020/21. The Ouse and Nene Washes hold the largest flocks, but keep an eye out anywhere in south-eastern England for small groups or herds which can turn up, sometimes in the company of their larger Whooper Swan cousins.

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The tiny breeding population of Purple Sandpipers in northern Scotland is joined by many more birds from Greenland and Norway for winter, which disperse around our rocky coasts.

Purple Sandpipers are seen as true winter visitors by many birders, with around 9,000 of these lovely waders spending the colder months across Britain and Ireland. This species is a very rare breeder in the far north of Scotland, so the bulk of the wintering birds are those which arrive from Greenland and Norway.

They are birds of rocky coasts and can be found feeding amongst the crashing waves as they pick up invertebrates washed in from the sea. In bright light, the purplish sheen that gives them their name can be seen on their mantle (back) feathers. More and more birds have been reported since mid November, with some sites playing host to small flocks.

Reports of Mediterranean, Great Black-backed, and Caspian Gulls were also on the rise in November, and these birds have now been joined by the first Iceland and Glaucous Gulls of the year. Both of these latter species breed north of the UK; they look similar to Herring Gulls but lack the black wing-tips, instead having white primaries that earn them the nickname ‘white-wingers’. Numbers are, however, lower than expected for this time of year, perhaps due to a lack of northerly winds which usually carry these birds to the UK in recent weeks.

Help us monitor wintering gulls

You might already be sending us your gull records through BirdTrack, but did you know we are also looking for volunteers for the Winter Gull Survey?

If you are confident identifying the six main species of gull found in the UK in winter – Herring, Lesser Black-backed, Great Black-backed, Black-headed, Common and Mediterranean – visit the WinGS project pages to find out more about taking part.

Volunteers will only need to make a small number of visits to gull roosts between 2023 and 2025, but their contributions will help us fill in vital gaps in our understanding of these Amber- and Red-listed species.

How to take part in WinGS

Finches, larks and buntings

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Flocks of Twites are becoming increasingly scarce as the species’ population declines.

A scattering of Snow Bunting and Shore Lark reports have been a delight; both species are firm favourites with birders during the winter. Snow Buntings in particular can form large flocks, and their striking black and white wing pattern is very distinctive when they are seen in flight.

Twites are closely related to Linnets, and as their old English name Mountain Linnet suggests, they have a preference for upland habitats. However, after the breeding season, British Twites move away from higher altitudes and spend the winter around our coasts. The declining population means records are becoming scarcer – traditional wintering areas such as Thornham in North Norfolk have seen numbers dwindle each year, and the species is now a rare winter visitor in Norfolk where double-figure counts were once regular.

So far this winter, reports have again been low, with the highest counts coming from a couple of locations in Northumberland and Lancashire. Two birds spotted in Kent have been popular with birders due to the paucity of this species there in recent years. It is worth checking any finch flocks you may encounter at the coast; the Twites’ pale yellowish bill and pink patch above the tail help differentiate them from the similar-looking Linnet.

Rarities and scarcities

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The Canvasback is closely related to the Pochard, a more familiar species for UK birdwatchers.

Since the last blog, the rarity highlights have had an American bias: a Cape May Warbler in the Isles of Scilly, the first White-crowned Sparrow for Cornwall, an American Robin and a Rose-breasted Grosbeak in County Cork and a Baltimore Oriole in Fife all originated from the other side of the Atlantic.

A Brünnich’s Guillemot in the Scottish Borders and a Little Crake in Buckinghamshire provided further interest, while a Canvasback in Essex sparked some lively discussion as to its origins – a transatlantic vagrant or simply a fence hopper from a wildfowl collection?

This handsome duck is a North American species, closely related to the Pochard, Tufted Duck, and Greater and Lesser Scaup. It is a rare visitor to the UK and findings are often contested because it is a popular species in ornamental duck ponds, making records tricky to verify.

“A Canvasback in Essex sparked some lively discussion as to its origins – a transatlantic vagrant or simply a fence hopper from a wildfowl collection?”

Looking ahead

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Ground-feeding species such as Woodcock need to find unfrozen earth in which to feed during cold weather.

As we edge ever closer to the shortest day of the year, large-scale migration slows week by week with the main drivers of bird movements being freezing weather and snow.

The Gulf Stream keeps temperatures a few degrees warmer across much of Britain and Ireland compared to the rest of Europe, and it is during times of prolonged freezing temperatures and snow that several species head to our shores to escape the harsh weather. These cold weather movements are very dependent on the extent of the freezing conditions and their duration; the longer these cold snaps last and the larger the area they affect, the greater the likelihood that birds will arrive here.

Species displaced by such extreme cold periods are typically those that live on or near water or need soft ground in which to feed. Waterfowl are often forced to migrate in search of open water in icy conditions, with a variety of ducks, geese, and swans arriving en masse. These might be joined by ground-feeding species such as Snipe, Woodcock, and thrushes in search of unfrozen earth to probe for worms and other invertebrates.

“Species displaced by extreme cold periods are typically those that live on or near water, or need soft ground in which to feed – look out for ducks, geese and swans as well as Snipe, Woodcock and thrushes.”

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As the winter progresses, more Glaucous Gulls are likely to arrive in the UK. Look out for their huge size and pale plumage.

Cold winds are also likely to bring more Iceland and Glaucous Gulls to our shores. These are regular winter visitors to Britain and Ireland, but the numbers arriving each winter are very dependent on the weather with the bulk of birds arriving during northerly winds.

This year, there have only been a couple of days when this type of weather pattern has occurred, and as a result, only a scattering of birds have been reported, mainly in the Outer Hebrides, Western Scotland, and Northern Ireland. As the winter progresses, more are likely to arrive, especially after any winter storms that have tracked across Iceland. Most of the birds that turn up here will be in their first winter, and their pale milky-tea plumage helps pick them out from similarly aged Herring and Lesser Black-backed Gulls.

Even if there isn’t any particularly cold weather across Europe, winter is always a good time of year to look for Bullfinches. These are secretive birds and can be difficult to see during the summer months, which is surprising given their large size and bright plumage. Any areas of dense scrub with some larger bushes are worth checking; Bullfinches will often feed on the berries of hawthorns. Their soft “heeew” call is worth learning as they are more often heard than seen.

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“Bullfinches can be extremely secretive but listening out for their soft call is a good way of finding them.”

Now is also a good time of year to look for some of the scarcer grebe species. Varying numbers of Black-necked, Slavonian, and Red-necked Grebes winter across the country and can be found on a variety of waterbodies, from lakes and inland lochs to estuaries and even on the sea.

Black-necked and Slavonian are the smallest of the three – a bit bigger than Little Grebes, with white and dark grey plumage that helps separate them from this browner-plumaged cousin. Learn how to distinguish Black-necked and Slavonian Grebes in our winter grebe ID video.

Red-necked Grebes are slightly smaller than Great Crested Grebes but share a similar body profile of a long neck and sleek body, but the neck tends to be dirtier looking than the pristine white seen on Great Crested Grebes.

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Look out for Blackbirds feasting on winter berries.

Any trees or shrubs with berries are worth checking regularly: Blackbird, Redwing, Fieldfare, Waxwing and even the occasional overwintering Blackcap can be found feasting in them.

You can attract many of these birds to your garden by putting apples out, with the added bonus of being able to watch the birds from the comfort of your own home! Who knows, you may even attract a rarity – Black-throated Thrush and Dusky Thrush have both been found in people’s gardens in recent winters.

Other rarities that have occurred at this time of year include Blyth’s Pipit, Baikal Teal, and Ivory Gull, all of which are sure to brighten up the dullest of winter days.

Tracking avian influenza: send us your records with BirdTrack

So far this winter, cases of avian influenza seem to be falling – but we still urgently need your help to monitor the spread of the disease.

It’s quick and easy to submit cases to Defra or DAERA and BirdTrack, and gives us vital information about cases in real time.

Learn how to report cases of avian influenza

December 2023

Winter is often regarded as the season when nature sleeps. But birdwatching in the colder months can be extremely rewarding, with local migration and huge irruptions of birds occurring across Europe in response to the changing weather conditions.

Goldeneye, by Sarah Kelman / BTO

08 Dec 2023

BirdTrack Migration

Climate change and migratory species: a review of impacts, conservation actions, indicators and ecosystem services.

MIKETOMS — Fri, 08 Dec 2023 11:02:29 +0000

The Cuckoo cohort of 2024 takes flight!

More Details

Williams, J.M., Scott, S.E., Galbraith, C.A., Martay, B., Macphie, K.H., Hereward, H.F.R., Barton, M.G., Bowgen, K.M., Pearce-Higgins, J.W. & Robinson, R.A. 978-0-86139-000-7 The study ‘Climate change and migratory species: a review of impacts, conservation actions, indicators and ecosystem services’ was commissioned by the Government of the United Kingdom of Great Britain and Northern Ireland through the Joint Nature Conservation Committee (JNCC) as a major contribution to the work of CMS on climate change and prepared by the British Trust for Ornithology (BTO).

BirdTrack migration blog (end of October to mid November)

SCMAYSON — Fri, 03 Nov 2023 10:18:29 +0000

Even as we reach the beginning of November, autumn migration is still very evident. Birds continue to arrive in the UK from more northerly regions to spend the next few months here in our warmer winters, before departing again next spring. Yes

Scott Mayson

BirdTrack Organiser

Scott’s role includes the day-to-day running of BirdTrack: updating the application, assisting county recorders by checking records and corresponding with observers.

Scott Mayson

BirdTrack

Migration

The influx of Waxwings that started at the beginning of October shows no signs of slowing as more and more flocks of this delightful winter visitor are reported across the country. Initially, reports were mostly confined to the Shetland Islands and some parts of northern mainland Scotland, but in the past week, increasing numbers of birds have moved down through the UK with some reported as far south as the Isles of Scilly.

Around 450 Waxwings were reported in total, with the biggest flocks still seen in Scotland – 200 in one flock in Moray and Nairn, and a flock of over 100 in Aberdeenshire. However, a flock of over 90 in Northumberland showed it wasn’t just the odd individual heading south. In Norway, Sweden, and Finland birds are still pushing south and east – so with luck, more flocks will cross the North Sea and arrive here over the next few weeks.

In Norway, Sweden, and Finland Waxwings are still pushing south and east – so with luck, more flocks will cross the North Sea and arrive here over the next few weeks.

While the peak of Redwing migration has passed, that of another Fennoscandian visitor is still in full swing: Fieldfares continue to arrive, with birds widely reported across the country. Groups arriving along the east coast tend to head straight inland, only stopping for a few minutes to feed before taking flight again in garrulous flocks. Their loud “black jack” call is a good indicator of their presence, and when they form mixed-species flocks, is often accompanied by the Redwings’ high-pitched “zeeep” and Blackbirds’ scolding “pink pwink pwink”.

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The BirdTrack reporting rate for Woodcock in 2023 (green) compared to historical data from 1927–2022 (red) shows the usual autumnal influx of this species to the UK.

Woodcocks continue their steady arrival as birds depart their core breeding range of Russia and Fennoscandia and head west to winter across Britain, Ireland, and western Europe. Birds have been known to migrate to the UK from as far east as central Russia. The most recent data suggest that almost one and a half million birds winter here, but we also know that the total number fell by around 16% between 1996 and 2004. The cause of this decline is not well known but could be related to the changing management of woodland and scrub.

Each autumn, flocks of Woodpigeons heading south are a common sight all across the UK – a great example of visible migration or ‘vismig’, bird migration that is visible during daylight hours. Where these Woodpigeons have come from and where they are going is still not fully understood. However, it’s thought that some birds arrive in the UK from north-west Europe, and some of ‘our’ breeding birds head south to winter in the oak forests of Portugal.

In the past few weeks, flocks of Woodpigeons have been widely reported, and among these, increasing numbers of Stock Doves – closely related to Woodpigeons – have also been noted. Their smaller size and lack of a white bar in the wing help birders pick them out from the commoner Woodpigeons.

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Snow Buntings arrive from both Iceland and Fennoscandia to spend the winter in the UK.

A spike in Snow Bunting records was bang on time, corresponding with the annual arrival that is expected around the end of October. These wintering birds can often be found along coastal areas, where they will sometimes mix with Linnets, Twites, Lapland Buntings and Skylarks.

Snow Buntings that breed in Scotland have been joined by birds from Iceland, Fennoscandia and north-west Russia.

Snow Buntings breed across a wide swath of arctic, high alpine, and tundra regions, and within these areas, there are a few different subspecies. The 75 or so pairs that breed in Scotland are of the Plectrophenax nivalis insulae subspecies, and in winter, these are joined by birds of the same subspecies that breed in Iceland. The P. nivalis nivalis subspecies breeds in Fennoscandia and north-west Russia and migrates to the UK to join the insulae subspecies over the winter. Separating nivalis and insulae in the field is possible, but can be very tricky.

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Water Pipits prefer reed-edged pools and flooded grasslands in the winter months.

The last week has also seen an increase in reports of Water Pipit. This species is a scarce but regular winter visitor from central and southern Europe where it prefers to breed in alpine areas, descending from the higher altitudes in autumn. During the winter, as their name suggests, Water Pipits have a preference for damp habitats, with reed-edged pools and flooded grasslands being particular favourites.

During the winter, Water Pipits move from their alpine breeding grounds to lower-altitude, damp habitats like reed-edged pools and flooded grasslands.

The greyer plumage and bold eyestripe of Water Pipits are helpful identification features which separate them from Meadow and Rock Pipits. You can brush up on your pipit identification skills with our Bird ID video, Identifying Water Pipit and Rock Pipit.

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Great Grey Shrikes are regular but scarce winter visitors to the UK. Numbers vary each year, but some sites see birds returning each winter.

A late flurry of scarce migrants was mostly concentrated in the north-east, but some birds were found further south and west as they filtered down the country, probably having arrived a few days earlier. The bulk of these reports was made up of Pallid Swift, Dusky Warbler, Pallas’s Warbler, and the odd Great Grey Shrike. Many will be hoping that it is a good year for the latter species, which is a firm winter favourite for plenty of birders.

Many will be hoping that it is a good year for Great Grey Shrike – this handsome species is a firm winter favourite of many birders.

The highlight in terms of rarities was a Two-barred Greenish Warbler that took up temporary residence at Flamborough; this species is usually found in Asia, across Mongolia, southern Siberia and north-east China. A Solitary Sandpiper, the American cousin of our more familiar Green Sandpiper, played hard to get in Kent with many keen birders searching for it – it has been 12 years since the last record of this species in mainland Britain.

Looking ahead

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Bewick’s Swans are slightly smaller than Whooper Swans, and have a rounded yellow patch on the bill. This patch is sharply triangular in Whooper Swans.

Although the peak of autumn migration has passed, birds will still be arriving over the coming weeks ahead of the colder temperatures of winter. Starlings, as mentioned in the previous migration blog, migrate here from all across north-eastern Europe and more will arrive in the coming weeks, especially if we get any easterly winds.

Bewick’s Swans, the Whooper Swans’ smaller cousins, begin arriving in larger numbers throughout November from their breeding areas across the Arctic and north-eastern Russia. Family groups migrate together and will stay in groups for much of the winter before they head back north and east in late February.

Like Bewick’s Swans, Tundra Bean Geese tend to arrive later in the year than other wintering wildfowl and breed across the Arctic and north-eastern Russia. Look out for their orange legs and the orange band on their bill which helps to distinguish them from similar-looking Pink-footed Geese.

Look out for Tundra Bean Geese – their orange legs and the orange band on their bill helps differentiate them from Pink-footed Geese.

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Look out for Red-throated Divers feeding amongst Great Crested Grebes just offshore.

A visit to the coast at this time of year can be rewarding, with flocks of sea ducks, divers and grebes gathering offshore. It can be surprising to see flocks of Great Crested Grebes sitting on the sea, but during the winter they are just as at home there as they are on freshwater. In some places, you can see good numbers feeding offshore amongst groups of Red-throated Divers.

If we get any strong northerly winds in the next few weeks, a visit to the coast could also be rewarded with a sighting of a Little Auk. This diminutive relative of the Guillemot breeds much further north and, although small in size, is a robust bird that spends much of its life at sea. During storms, large numbers can be seen passing headlands and can sometimes turn up inland. They even have a habit of mixing in with flocks of Starlings crossing the sea.

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Any flock of scoters is worth checking for a vagrant Surf Scoter. Small numbers are found each winter off the UK’s coast, and the males – with their distinctive bill and white nape patch – stand out from the plainer-looking Common and Velvet Scoters.

Large flocks or ‘rafts’ of sea ducks, especially Common Scoters, will be worth checking for Velvet Scoters – these are surprisingly easy to spot thanks to their slightly stockier build, a white spot behind the eye and an obvious white wing flash, all of which make them stand out in large rafts of birds. The occasional Surf Scoter may also join these, particularly in flocks off the east coast.

The forecast for the next week is for more low-pressure systems to bring wet and windy conditions to most parts, which may well bring some more American vagrants to our shores. Fast-moving systems that originate along the eastern seaboard of the USA and cross the Atlantic in a couple of days tend to be the most productive for birdwatchers – sadly, systems that take longer to move over the ocean see fewer of the migrant birds caught up in the winds survive the epic crossing.

Similarly, the most likely species to make it across the Atlantic at this time of year are larger birds, such as wildfowl and gulls, as smaller birds are less able to withstand the stormy conditions and extended periods over open water. Species such as Bufflehead, Lesser Scaup, Ring-necked Duck, and Green-winged Teal all have a history of arriving off the back of these weather systems. Bonaparte’s, Laughing, and Ring-billed Gulls are also likely, and maybe even a Franklin’s Gull.

In terms of smaller transatlantic vagrants, Chimney Swift, Mourning Dove, Blackpoll Warbler and American Robin are all possible, so keep your eyes peeled.

Send us your records with BirdTrack

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November 2023

Stock Dove, by Liz Cutting / BTO

03 Nov 2023

BirdTrack Migration

Arctic Skua migration: stories from the field

WEBSITEEDITOR — Fri, 13 Oct 2023 16:18:50 +0000

Where do Arctic Skuas go when they are not in Scotland? Helen and David Aiton take us through their fieldwork seasons for BTO’s Arctic Skua tracking project, which has followed these fascinating birds across both hemispheres and back. No

Helen and David Aiton

Helen and David Aiton have been members of BTO for over 40 years. Over this period, they have contributed to many BTO surveys and currently have a Breeding Bird Survey site on Rousay.

We were drawn to these beautiful birds by their plaintive calls, their stunning range of plumages and – sadly – their rapid population decline. In 1991, there were 122 pairs in our study area along with thousands of Arctic Terns. Now, in 2023, there are only 17 Arctic Skua pairs and a mere handful of breeding Arctic Terns. This trend reflects that of the UK breeding population more broadly, which is restricted to north and west Scotland and has declined by 70% since 2000.

Our fieldwork site is a triangular area of coastal moorland approximately 2 km by 1.5 km and varies from 5–115 m above sea level. We also research Great Skuas in our study area – but that is a story for another time! The aim of our long-term study is to monitor how both skua species are faring in these turbulent times.

This year, 2023, was the 10th season of our Arctic Skua productivity study, which measures the breeding success of the colony. We collect information about the number of eggs, chicks and fledged young every breeding season. Over the past 10 years, our colony has fledged 96 juvenile birds.

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A newly hatched Arctic Skua chick with its ‘egg tooth’, a sharp point on its beak that helps the chick to break the eggshell from the inside when it is ready to hatch. The egg tooth falls off the beak around a day after hatching.

Fieldwork on Rousay

Each year we visit the study area at least eight times, an effort of 16 days minimum. The island can be reached by a 30-minute ferry trip, crossing the beautiful Eynhallow Sound. Our fieldwork is made more comfortable in our old VW Campervan for overnight stays.

We locate nests at the start of each breeding season from vantage points at least 200 metres away: one person remains at the vantage point and directs the other using radios, to as many as five nests at a time. Arctic Skua nests are well hidden, so we have to use sightlines and surrounding vegetation to memorise their positions, so we can monitor them throughout the season.

Arctic Skua nests are well hidden, so we have to use sightlines and surrounding vegetation to memorise their positions.

We also use our two highly-trained German Shorthaired Pointers to increase the efficiency of finding chicks which have become more mobile and might have wandered away from the nest. It’s very important that we only undertake nest and chick finding in dry, warm weather to avoid the risk of causing any harm due to chilling.

The Arctic Skua tracking project

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Helen holding an adult bird ready for release. The geolocator is attached to the uniquely-coded orange ring on the Arctic Skua’s left leg.

Liz Humphreys from BTO Scotland contacted us in 2018, having heard about our well-established study. BTO’s scientists were keen to use geolocators to track the adult Arctic Skuas, to find out where they spent their winters, and to learn more about their migration routes. This information would help inform conservation efforts to protect this species. The work on Rousay would build on the study of Fair Isle breeding Arctic Skuas, which BTO began in 2017, and offer a comparator site. Fair Isle is roughly 30 miles from Orkney.

BTO’s Senior Research Ecologist John Callandine joined us for a week on Rousay, arriving in late May 2018. Luckily for John, we had a week of hot, dry and still weather, almost unknown in Orkney – highly suitable conditions for checking nests and catching adult birds for tagging. He was delighted that we had already located the nesting birds.

Luckily, we had a week of hot, dry and still weather, almost unknown in Orkney – highly suitable conditions for checking nests and catching adult birds for tagging.

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John (left) and David (right) place a walk-in trap over dummy eggs in the nest cup. The real eggs are safely stored in the box John is holding.

For the tagging project, we chose mostly well-established pairs of adult birds. Over the next few days, we watched the birds and waited for them to lay a full clutch of eggs. We then prepared the walk-in traps – safe structures for catching the adult birds – and left them for a couple of days near the nests, to habituate the birds to them.

Eventually, we placed the traps over the nests, to catch the adults as they walked onto the nest to incubate the eggs. To keep the eggs safe from predators while we tagged the adults, we removed them temporarily and replaced them with dummy eggs before putting the walk-in trap over the nest.

John had honed the techniques for catching birds on Fair Isle the year before, so we were a slick team! We caught 10 individual birds, two of which were a pair. As soon as the tagging was finished we replaced the real eggs. The whole process never took more than an hour.

John then left Rousay to go to Fair Isle to catch more birds, and we continued our study for the rest of the summer. It was reassuring that the birds with geolocators continued to behave normally, with most of them rearing chicks successfully that year.

Collecting the geolocator data

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Arctic Skua plumage falls broadly into two ‘phases’: pale phase (as in the bird in the top photograph) and dark phase (as in the bird in the bottom photograph). Plumage which is intermediate between these phases can also occur in some birds.

Using geolocators as a tool to understand migration routes does not provide instant gratification. To collect the data from the geolocators, they have to be retrieved from the birds, which meant we had to catch the tagged birds again to get any information at all! Innocent of the wiles and intelligence of Arctic Skuas we returned to Rousay in late spring 2019, keenly anticipating retrieving the geolocators and continuing our productivity study.

John joined us again in early June to begin the retrieval process and repeat the procedure using the walk-in traps. However, of the 10 birds we caught in 2018, only eight birds had returned, and one of the birds that did return tried to breed, but her nest failed before we had a chance to try to recapture her with the walk-in traps – down to seven birds.

Arctic Skuas share incubation duties, with both the male and the female sitting on eggs. Because individual Arctic Skuas can occur in one of two plumage types – birds are either ‘dark’ or ‘pale’ phase – we could tell the male and female apart if they had different phase plumage, what we called a ‘dark-pale phase pair combination’. But for a dark-dark phase pair combination, where only one of the pair was carrying a geolocator, we had to take extra care to ensure we were catching the right bird.

The first bird we tried to catch, a female pale-phase bird, walked straight into the walk-in trap and onto the dummy eggs – hurrah – Geolocator Number 1. After this, we thought – this was going to be easy! Alas not. That was the only geolocator retrieved during John’s visit, despite trying for the remaining six birds who all refused to go back into a walk-in trap.

Later in June, we tried mist-netting one pair that had a young chick. A mist net is a fine mesh held taut between two vertical poles, which we can use to safely catch birds by encouraging them to fly or walk into it (in this case, by placing a stuffed predator close by to the net in the hope that the adult birds would fly into the net while mobbing it) but the adults very cleverly called the chick away from the net instead. Sigh!

We were fortunate that one pair – which had had a single egg predated by a neighbouring Arctic Skua (quite common in the skua colonies) – re-laid, and had a young chick less than a week old in late July. With both adults close to their nest, we had the opportunity to try recatching them, and this time both threw themselves into the mist net at the same time! Geolocator Number 2 retrieved.

As in 2018, the colony went on to successfully fledge chicks, including that late chick.

A brief hiatus ...

Due to COVID-19 restrictions in 2020, we were not able to return to Rousay until early July, by which time the chicks were too old for us to try to catch the adults with a mist net. Again, though, it was a good year for the Arctic Skuas and they fledged at least 10 chicks.

... before fieldwork resumed

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John (left) and David (right) relaxing on the Rousay pier after fieldwork was complete.

In 2021, three years after putting the geolocators on the birds, John joined us again in glorious weather in early June. There were still four birds with geolocators breeding in the colony. We successfully mist-netted a female using dummy eggs and a stuffed predator, which she duly mobbed and entered the mist net – Geolocator Number 3 retrieved.

John and David worked very hard to retrieve the remaining three geolocators, but the birds refused to engage with the walk-in traps or the mist nets. Later in June, we tried again with the dark-phase male mate of the first pale-phase bird we retrapped in 2019 – and success! – he eventually walked into the trap and settled on the dummy eggs – Geolocator Number 4. We hoped at the very least that the birds we recaught to retrieve the geolocators this year would give us two years’ worth of migration information.

Finally, after approximately 200 hours of effort, we had four geolocators retrieved, along with six geolocators from John’s work on Fair Isle. The BTO team could set about retrieving the data from the geolocators and plotting the migration routes of the 10 Arctic Skuas. It is no exaggeration that we were all thrilled to see the results.

Migration stories revealed

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Circles show the different wintering locations of individual Arctic Skuas, each of which is represented by a different colour. Two circles of the same colour represent the wintering locations of the same bird in consecutive winters. Different birds from the same breeding colony spent our winter months off the coast of north-west Africa, south-west Africa, or the east coast of South America. The triangle shows the location of Rousay, Orkney, where the Arctic Skuas breed.

The data showed that all the Arctic Skuas travelled south via the North Sea and English Channel. Then down past France, Spain and Portugal to the coast of north-west Africa and on to their wintering grounds.

Individual Arctic Skuas wintered in different locations: off the coast of north-west Africa, the coast of south-west Africa or the east coast of South America. The accuracy of the data is roughly to the nearest 200 km so the birds are not actually on land, as can appear in the maps of the location points – they overwinter at sea. The birds that had data over two winters went back to the same area each year. Astonishingly, our pair of birds that both had geolocators went to different continents!

The work we did in Scotland will also be part of a multi-colony study of Arctic Skua wintering and migration movement involving colonies right across their north-east Atlantic breeding range – some of which was presented by BTO Senior Research Ecologist Nina O’Hanlon to the International Seabird Group Conference in Cork in September 2022 and has now been submitted for peer review. You can read more about the project’s findings in Nina’s blog.

It is rewarding to see the work we contributed to being part of a published international study. Even two years after the maps were produced, it is still deeply satisfying to be able to visualise the journeys of the Arctic Skuas when they are not on Rousay.

Since the Arctic Skua research programme was established in 2017, BTO donors have donated more than £225,000 to fund the work. We are enormously grateful for this very generous support from a small number of committed individuals. The research could not have been delivered without this funding. We would also like to thank the Scottish Ornithologists’ Club for annual grants that cover the cost of the productivity study on Rousay.

World Migratory Bird Day 2023

This blog post was created to celebrate World Migratory Bird Day (WMBD) 2023, a global event which increases the level of awareness about the threats that migratory birds are facing.

The theme of WMBD 2023 is Water, which highlights the importance of this resource for migrating birds – including for species like the Arctic Skua, which spends most of its life at sea and migrates thousands of kilometres over the ocean and across both hemispheres every year.

BTO’s Arctic Skua tracking project aims to understand where these birds spend their time when they’re not at their breeding colonies, so we can better inform global efforts to protect this species.

Discover more about Rousay’s Arctic Skuas and their astonishing migration in our other blog for WMBD 2023, written by BTO Senior Research Ecologist Nina O’Hanlon.

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Helen and David Aiton take us through their fieldwork seasons for BTO’s Arctic Skua tracking project.

1 October 2023

Where do Arctic Skuas go when they are not here?

For us, ‘here’ is Rousay, an island which lies off the West Mainland of Orkney. We have been measuring the breeding success of Arctic Skuas since 2014, and working with BTO to help track the adult birds’ migration since 2018.

13 Oct 2023

Scotland

Combining remote sensing and tracking data to quantify species’ cumulative exposure to anthropogenic change

VIOLA.ROSS-SMITH — Tue, 10 Oct 2023 09:15:21 +0000

The Cuckoo cohort of 2024 takes flight!

More Details

Buchan, C., Gilroy, J.J., Catry, I., Hewson, C.M., Atkinson, P.W. & Franco, A.M.A Global Change Biology 10.1111/gcb.16974 Identifying when and where organisms are exposed to anthropogenic change is crucial for diagnosing the drivers of biodiversity declines and implementing effective conservation measures. Accurately measuring individual-scale exposure to anthropogenic impacts across the annual cycle as they move across continents requires an approach that is both spatially and temporally explicit—now achievable through recent parallel advances in remote-sensing and individual tracking technologies. We combined 10 years of tracking data for a long-distance migrant, (common cuckoo, Cuculus canorus), with multi-dimensional remote-sensed spatial datasets encompassing thirteen relevant anthropogenic impacts (including infrastructure, hunting, habitat change, and climate change), to quantify mean hourly and total accumulated exposure of tracked individuals to anthropogenic change across each stage of the annual cycle. Although mean hourly exposure to anthropogenic change was greatest in the breeding stage, accumulated exposure to changes associated with direct mortality risks (e.g., built infrastructure) and with climate were greatest during the wintering stage, which comprised 63% of the annual cycle on average for tracked individuals. Exposure to anthropogenic change varied considerably within and between migratory flyways, but there were no clear between-flyway differences in overall exposure during migration stages. However, more easterly autumn migratory routes were significantly associated with lower subsequent exposure to anthropogenic impacts in the winter stage. Cumulative change exposure was not significantly associated with recent local-scale population trends in the breeding range, possibly because cuckoos from shared breeding areas may follow divergent migration routes and therefore encounter very different risk landscapes. Our study highlights the potential for the integration of tracking data and high-resolution remote sensing to generate valuable and detailed new insights into the impacts of environmental change on wild species. The BTO Cuckoo Tracking Project was funded by the A. G. Leventis Foundation, BBC Wildlife Fund, Dulverton Trust, BTO including from much appreciated gifts in Wills, Ernest Kleinwort Charitable Trust, Essex and Suffolk Water, Mark Constantine, Tobit Trust and ‘Cuckoo Sponsors and Champions’. The authors thank everyone who provided assistance in the field, Paul and Russell Howey for assistance with PTTs, and BTO Fundraising and Communications teams for vital contributions to the project. CB was funded by a PhD studentship from the Natural Environment Research Council, grant number NE/L002582/1. IC was funded by contract 2021.03224.CEECIND from FCT (Fundação para a Ciência e Tecnologia).

BirdTrack migration blog (22–28 September)

SCMAYSON — Thu, 21 Sep 2023 10:26:45 +0000

The speed of migration has picked up as the end of September draws near, with a mix of extremely rare species and more common migrants being seen in recent days. There are still a few weeks until autumn migration starts to slow down; who knows what they will bring? No

Scott Mayson

BirdTrack Organiser

Scott’s role includes the day-to-day running of BirdTrack: updating the application, assisting county recorders by checking records and corresponding with observers.

BirdTrack

As always, the weather is a huge factor in which species are seen where across Britain and Ireland, and the past week has been no exception. A spell of north-westerly winds on Sunday provided a wealth of seabirds along the east coast, with good numbers of Sooty Shearwaters seen. Mixed in were several Balearic Shearwaters and the odd Cory’s Shearwater, both of which are far more regular off southern coasts and would have been a welcome sight for many an east coast birder. With an increase in Kittiwake and tern reports came a similar increase in Arctic Skua reports. This is typical for this time of year as both adult and young birds head south, harassing Kittiwakes and other seabirds along the way to give up their food.

After a slow start to autumn migration, reports of Grey Plover jumped up last week, as birds dispersed away from their Siberian breeding grounds, no doubt taking advantage of the north-easterly winds. While some of these Grey Plovers will stay and spend the winter around the coast and on estuaries, others will continue south to winter in western and southern Africa. The black ‘arm-pit’ is a good identification feature on flying birds and helps separate them from Golden Plovers, as both species can look similar at this time of year when they are in their non-breeding plumage.

On land, these same winds produced a variety of common migrants, with increased reports of both Blackcap and Chiffchaff. This is now the peak of their autumn passage, and numbers will drop as we progress into October. A smaller arrival of Pied Flycatchers and Redstarts also brought with it the first Yellow-browed Warblers of the autumn, with around 60 birds reported from Shetland in the north to Scilly in the south. This species is a regular autumn migrant and a favourite with birdwatchers, and they can be found not only at coastal sites but also inland. Alongside the first Yellow-browed Warblers, a scattering of Barred Warblers and Red-breasted Flycatchers was also noted, as well as two Red-flanked Bluetails. Many will be hoping for more Red-flanked Bluetails later in the autumn, as this once ultra-rare species has expanded its range across Finland and is breeding in ever-increasing numbers. As a result, it is becoming a more frequent passage migrant.

We don’t generally think of Robins and Dunnocks as migratory species, but in the last couple of weeks, birds have been arriving from across Europe to spend the winter here. Numbers along coastal sites have increased, and over the next few weeks these birds will disperse inland. The Robin you see in your garden over the winter could in fact be a bird that bred in Poland or Germany.

On Wednesday, a fast-tracking low-pressure system moved across the Atlantic. Not only did this bring strong winds and rain to many parts of the country, but it also brought with it a deluge of American birds. At the time of writing, the tally of American waifs consisted of Bay-breasted Warbler, Blackburnian Warbler, Magnolia Warbler, Tennessee Warbler, Alder Flycatcher, Bobolink, Black-and-white Warbler, Baltimore Oriole, Buff-bellied Pipit, four American Cliff Swallows, and eight plus Red-eyed Vireos. It is likely that more will be found over the next couple of days.

Ring Ouzels start to pass through Britain and Ireland from the middle of September onwards.

Looking ahead

Next week looks to pick up where this week left off, with the remnants of Hurricane Nigel hitting the west coast on Monday. This will bring another batch of high winds and rain for many parts as it tracks across the country and may well produce another few American passerines. For anyone able to get to the west coast on Monday, checking the headlands and coastal scrub after the rain has passed could provide you with a dream rare bird. For the rest of the country, the coming weekend and following week look less than ideal for migration, with strong westerly and southerly winds forecast. What this does mean is that those migrants that are already here are unlikely to move too far, which gives you a chance to check lots of locations. Species like Swallow and House Martin will flock together, often hunting over waterbodies to build up their fat reserves ready for when the weather does clear. The same is true for other species, such as warblers and chats, which will take advantage of what seems to be a good berry year and feast while they can.

The usually shy Jay become more obvious in autumn as they search out acorns to stash ready for the winter.

A brief spell of easterly winds on Thursday could see migration pick up a little, and those birds that have been held up here will push south. Species to look out for include Ring Ouzel, Pied Flycatcher, Goldcrest, Skylark, Short-eared Owl, and Jay. While we may think of Jay as being fairly sedentary during the autumn, they become more conspicuous as they search out acorns, which they stash to feast on during the winter months. During years when there is an acorn shortage, irruptions of Jays can occur with birds from populations in Fennoscandia heading south and west in search of food. 2013 was one such year, and flocks of 10 or more birds were seen along eastern coasts. This year looks like it is a good acorn year, so such an irruption is unlikely, but it is still a good time of year to look for dispersing juveniles and adults looking for acorns.

2 September 2023

22 Sep 2023

BirdTrack Migration

BirdTrack migration blog (15–21 September)

SCMAYSON — Fri, 15 Sep 2023 08:37:38 +0000

Now we are moving into mid September, BirdTrack reporting rates have increased for many passage migrants and winter visitors. This is especially true for several duck and wader species, which come to estuaries and wetlands across Britain and Ireland to feed up in large numbers.

Nina O’Hanlon

Senior Research Ecologist

Nina is a Senior Research Ecologist and part of the Wetland and Marine Research Team, based within BTO Scotland. Her role involves reporting, analysis and fieldwork with a focus on marine birds.

BirdTrack

Look out for the smaller Little Stints in amongst flocks of Dunlin. These small waders pass through Britain and Ireland each autumn.

Arrivals of Snipe, Dunlin and Curlew Sandpiper have noticeably increased recently, with the peak passage of Curlew Sandpipers likely to occur over the next week. Wigeon, Teal, Pintail and Shoveler also saw an increase in reporting rates which will continue over the next month, with birds moving south from their widely dispersed breeding grounds, from Iceland and Fennoscandia to Russia. Skeins of Pink-footed Geese continued to arrive adding to the autumnal feel despite the unseasonably high temperatures across much of the country last weekend. Seabirds also continue to feature, with reports of Leach’s Petrels beginning to increase.

As with last week, Meadow Pipits continue to be well recorded with clear skies in many areas over the weekend providing good visible migration opportunities. Reports of Chiffchaffs are also starting to increase, as mid to late September is the peak time for autumn passage of birds moving south from Fennoscandia. Keep an ear out for their “hweet” call.

Rarity highlights from the past week include a stunning American Yellow Warbler on Foula, Shetland – as bright as its name suggests – whilst a Sharp-tailed Sandpiper (an eastern Siberian breeder) was found at Montrose Basin in Angus. The Red-footed Booby remains off Scilly, and a Brown Booby has also been frequenting several buoys off Cleveland.

The silvery underwings of Sooty Shearwater are a good identification feature and can be seen even at long range.

Looking ahead

High pressure is set to build over the weekend with some dry, sunny spells and relatively light winds before heavy rain and thunderstorms are expected on Sunday, moving up from the south. Into next week, a period of low pressure will bring heavy rain and strong westerly winds – not the most favourable conditions for migration.

However, more waders are expected with arrivals of Dunlin set to continue along with Bar-tailed Godwits, Knot and Little Stints. The peak autumn passage of these latter three species typically occurs in mid September. A high proportion of birds found will be juveniles, which generally migrate later than adults. Juvenile waders tend to stop to feed up more regularly than adults, as older birds can make longer, non-stop, migratory journeys.

Internationally important numbers of Knot and Bar-tailed Godwits will stay and winter in estuaries around Britain and Ireland. However, Little Stints are largely passage migrants. These miniature waders only stop here briefly during their long southbound migrations between their breeding areas in Siberia and wintering grounds in Africa, with some individuals migrating over 12,000 km! Given that most will be juveniles, the number of autumn passage Little Stints not only depends on the weather but also on the year’s breeding success. This weekend marks the start of the winter priority period for the Wetland Bird Survey (WeBS), with Sunday being the core count date, so do keep an eye out for these waders while you take part.

Seawatching should continue to be fruitful, with this week typically being the peak passage time for Sooty Shearwaters. These elegant seabirds are all dark with silvery flashes on the underside of their long stiff wings. They have a powerful flight, and in high winds glide characteristically in high arcs over the waves. Mid September is also a good time for passage Arctic and Long-tailed Skuas – equally elegant seabirds that are a joy to watch.

1 September 2023

Snipe, by David Scott / BTO

Wetland and Marine Research Team

Surveys Team

BTO Scotland

15 Sep 2023

BirdTrack Migration

BTO - British Trust for Ornithology - Migration

Cuckoo Tracking Project

Help us follow Cuckoos on migration and discover why they are in decline

Progress so far

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Support the project

Watch the Cuckoos migrate on our map

Travel far, breed hard, die young! The surprising lifestyle choices of Short-eared Owls

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Remote tracking unveils intercontinental movements of nomadic Short-eared Owls Asio flammeus with implications for resource tracking by irruptive specialist predators

BirdTrack migration blog (winter 2023/24)

On the sea

Waxwings

Wildfowl, waders and gulls

Help us monitor wintering gulls

Finches, larks and buntings

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Looking ahead

Tracking avian influenza: send us your records with BirdTrack

Climate change and migratory species: a review of impacts, conservation actions, indicators and ecosystem services.

BirdTrack migration blog (end of October to mid November)

Looking ahead

Send us your records with BirdTrack

Arctic Skua migration: stories from the field

Fieldwork on Rousay

The Arctic Skua tracking project

Collecting the geolocator data

A brief hiatus ...

... before fieldwork resumed

Migration stories revealed

World Migratory Bird Day 2023

Combining remote sensing and tracking data to quantify species’ cumulative exposure to anthropogenic change

BirdTrack migration blog (22–28 September)

Looking ahead

BirdTrack migration blog (15–21 September)

Looking ahead

What’s next