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 26 October 2018

Eastern Promise

As expected, the northerly winds meant that migration was relatively quiet this week. However, a trickle of birds continued to arrive, most notably Common Crossbills. From Tuesday onwards, daily totals of up 200 birds were noted at Sandwich Bay Bird Observatory, Kent. Smaller numbers were recorded elsewhere along the south coast. The BirdTrack reporting rate graph shows as above average for the last few weeks so it is worth checking any local sites for birds on the move.

Thrushes and finches continued to arrive, albeit in smaller numbers with counts from bird observatories along the east coast in the low hundreds for both Fieldfare and Redwing. Most sites also held a Short-eared Owl or two and late October/early November is the peak time for this species based on BirdTrack reports.

Short-eared Owl by Mark Taylor/BTO

More unusual migrants included small numbers of Stock Doves arriving in off the North Sea along the south and south east coast. While birds breeding in Britain and Ireland are considered to be sedentary, the populations of Stock Dove in Scandinavia and eastern Europe are migratory. A handful of Waxwings were reported along the east coast, with most seen as fly-overs only.

Over the course of the weekend, the winds gradually shift from northwest to east, with strong northerly winds forecast for Saturday morning. Over 70 Pomarine Skuas were logged passing Titchwell, Norfolk this morning and tomorrow looks like a good day for this species, and other skuas, to be found along the east coast. The first Little Auks of the autumn may well be reported moving past offshore as well.

Little Auk by Morris Rendall/BTO

Based on current forecasts, the winds will remain easterly until Tuesday at least, which may well bring an arrival of Siberian migrants, including commoner species such as Brent Goose and Bewick’s Swan. Given the origin of the winds, a late arrival of Yellow-browed and Pallas’s Warblers seems possible, and any Wheatear is worth checking for something rarer, such as Desert or Pied Wheatear. There is always the potential for something unexpected turning up – a Siberian Rubythroat would brighten any day!

Stephen McAvoy

Friday 19 October 2018

Rare arrivals from east and west

Arriving quickly from the east coast of the United States and Canada, the remnants of Hurricane Michael did not directly impact Britain and Ireland last Monday, diverting southwest towards NW Iberia at the last moment instead. Despite this, the outliers brought several very rare North American birds with them. The first species to be found was also one of the rarest, with Britain’s second Grey Catbird found at Land’s End, Cornwall late on Monday. It remained on site all through the week, allowing many birders to catch up with this species. The offshore islands closest to the track of ex-Hurricane Michael were also good places to be with Cape Clear, Co. Cork holding a triple crown of Swainson’s Thrush, Scarlet Tanager and the first Veery for Ireland. Birders on the Isles of Scilly discovered Bobolink, Grey-cheeked Thrush and Red-eyed Vireo, though the former was only seen briefly. Away from the southwest, there were sightings of Red-eyed Vireo on Inishmore, Co. Galway and a Baltimore Oriole on Barra, Outer Hebrides. The fast moving nature of this Hurricane, taking just over 48 hours to cross the Atlantic, likely helped these birds survive the crossing. Who knows what other species may have been discovered if it had made landfall in Ireland or Britain?

Following on from the strongly southerly winds the previous weekend, Pallid Swifts were found in Kent, East Yorkshire and Northumberland. However, these were outshone by Britain’s first White-rumped Swift at Hornsea Mere, East Yorkshire last Sunday. With an increasing population in Iberia, this species should now be on the radar in similar conditions in future years.

Along the North Sea coast of Britain, strong northeasterly winds last Monday brought fresh arrivals of thrushes and finches arriving ‘in off’. Redwing, Fieldfare, Goldcrest and Brambling arrived, while scarcer migrants included Bluethroat, Red-flanked Bluetail, several Great Grey Shrikes and a probable Two-barred Warbler in Norfolk. The first Waxwings of the autumn were also reported from Shetland, Yorkshire and Norfolk – will this winter see another invasion?

Waxwing by Jeff Baker/BTO

Looking ahead, the weekend looks set to be dominated by high pressure, and the calm mornings are ideal for visible migration watches with larks, thrushes and finches on the move. The reporting rate graph on BirdTrack shows that late October is the peak for Skylark, Siskin and Brambling amongst others. One to listen out for is Richard’s Pipit, with fly-overs likely to be found anywhere. The BirdTrack reporting rate graph shows a clear peak in late-October, and it is well worth being familiar with the flight call (for example

Reporting rate graph of Richard's Pipit

On Sunday afternoon, the wind looks set to switch to northwesterly over most of Britain and Ireland, which will likely help birds staging from Iceland to our shores, for example Brent Goose and Whooper Swan.

Stephen McAvoy

Friday 12 October 2018

Looking east and west

The spell of northeasterly winds last weekend appears to have opened the floodgates for birds wanting to cross the North Sea from western Scandinavia. There was a notable passage of thrushes, consisting mainly of Redwing and Song Thrush, with a few Ring Ouzel noted. The movement also included some flocks of Fieldfare – appearing a little early based on the BirdTrack reporting rate.

Fieldfare by Luke Harding/BTO

Other winter visitors on the move included Whooper Swan and Brent Goose, while good numbers of duck were reported moving past coastal watchpoints along the east coast, especially on Sunday when the northeasterly winds were at their strongest.

Scarcer species noted included several Barred Warblers, the first Great Grey Shrikes of the autumn and the first significant arrival of Yellow-browed Warblers along the east coast.  Up until this weekend, it had been a very quiet autumn for this species by recent standards. However, 39 logged at Spurn, Yorkshire on the 7th October was both a record day count for the site and a very good count for this autumn. Over 20 were also logged at nearby Flamborough Head, Yorkshire, and single figure counts came from many coastal sites.

Great Grey Shrike by Graham Catley/BTO

Although the winds switched back to west–southwesterly from Monday onwards, these were sufficiently light that birds managed to cross the North Sea, with further arrivals of Song Thrush and Redwing. New arrivals included the first Brambling and several Olive-backed Pipits. Above average numbers of the latter have been reported from Poland and Germany so far this autumn, so more may yet be found.

On Thursday and Friday, the winds switched to a southerly direction in the wake of Storm Callum moving north off the west coast of Ireland. These winds originate from the Mediterranean basin and mid to late October is peak time for Pallid Swift in Britain so it will interesting to see if the southerly winds will push any our way.

Pallid Swift reporting rate on BirdTrack

Looking ahead, there are two weather systems to watch. On the east coast of Britain, there is potential for more northeasterly winds on Monday and Tuesday, which will likely bring more Scandinavian migrants, and perhaps something rarer. In the southwest, the remnants of Hurricane Michael could arrive on the same day. Having caused significant damage in northwestern Florida, this storm moved rapidly along the east coast of the United States and Canada. As of this morning, the storm could reach southwestern Ireland and Cornwall on Monday lunchtime, though there is still some uncertainty on the precise track the storm will take across the Atlantic. If it does reach our shores, it may well bring some very rare North American birds, with likely candidates including Chimney Swift, Red-eyed Vireo and Grey-cheeked Thrush. There is always the chance of something unexpected – a repeat of either Canada or Golden-winged Warbler would be very welcome!

Stephen McAvoy