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 23 May 2014

Migration slowing down

This week has been a classic mid-may week. Passerine numbers have slowed right down – most are now here and many are already feeding the young of their first broods – however, waders have been more prominent with some top drawer scarcities joining the Dunlin, Sanderling, Turnstone, Bar-tailed Godwit and Whimbrel as they pass through the UK to arctic breeding grounds. From the east, came a Terek Sandpiper, found in Lincolnshire and a Broad-billed Sandpiper also in Lincolnshire. Two summer plumaged Spotted Sandpipers, a couple of Lesser Yellowlegs and Pectoral Sandpipers and a Buff-breasted Sandpiper came from the west, whilst the south produced a further influx of Black-winged Stilts and a single Kentish Plover, we can expect more of the same over the next couple of weeks.

Terek Sandpiper by Andy Mason

With over twenty birds being reported at sites from the south coast as far north as Yorkshire, Bee-eater has to be the bird of the week. Other southern overshoots included at least ten Black Kites, five Hoopoes, five Red-rumped Swallows and at least three Great Reed Warblers, whilst a Red-footed Falcon and a handful of Red-backed Shrikes and Bluethroats and, at least two White-winged Black Terns came from the south-east.
Bee-eater by Su Gough

The biggest rarity of the week came in the form of one of the world’s rarest birds, a Cahow, or Bermuda Petrel, seen from a survey vessel 170 nautical miles WNW of County Kerry, and with a world population of around 500 birds it somewhat overshadowed Britain’s eighteenth Calandra Lark, found on Fair Isle.

With low pressure wheeling over the country and drawing air in from a southerly direction we may well see an arrival of Quail and a few classic mid-May birds such as Red-backed Shrike, Marsh Warbler and Wryneck, and if we get any appreciable easterly airflow, maybe a rarity such as Oriental Pratincole or Marsh Sandpiper, and if you’re out and about birding over the Bank Holiday weekend, don’t forget to submit your complete lists to BirdTrack and make your observations count.

Friday 9 May 2014

World Migratory Bird Day

This weekend sees the celebration of World Migratory Bird Day, an initiative that seeks to raise the profile of migratory birds across the world.

Cuckoo by Steve Ashton

Migration is probably one of the most hazardous things that any bird may undertake, our satellite tagged Cuckoos are testament to that. We have lost birds to bad weather; Martin the Cuckoo was caught in a severe and unseasonal hail storm in southern Spain in spring 2012. Other birds have been defeated by the extremely arduous crossing of the Sahara, whilst some found it difficult to fatten-up during the wet, cold 2012 summer here in the UK, hampering their progress south.

This spring seems to have been good to our Cuckoos and currently seven tagged birds have made it back to the UK, three to Scotland, three to East Anglia and a single bird to Dartmoor, almost at the exact location where he was tagged in 2013. Two birds are still on their way and are in France and Spain but we have lost two birds on the way. One, Tor, is almost certainly down to tag failure, his transmissions had become patchy during the winter, and the other, Ken, as he was preparing for his northward crossing of the desert – maybe he just couldn’t find enough food, or perhaps he was taken by a predator, we will never know for sure.

There are plenty of natural hazards but many migrants also have to run the gauntlet that the modern world throws at them. Chris Packham recently highlighted the plight of European migrants as they migrate through Maltese airspace, read more here. A small number of British migrants also use this route and 29 recoveries of birds ringed in Britain, of 14 different species, have come from Malta. Among these have been two British-ringed Cuckoos; indeed two of our satellite tagged birds have flown directly over Malta on their way to Congo.
Black Kite by Jill Pakenham

Whilst many birds perish during migration, many successfully make it back. The weekend just gone saw the mass arrival of Swifts to the UK, the first wave of Spotted Flycatchers and the first Nightjar. There was also a good showing of southern overshoots, with multiple arrivals of Hoopoe and Black Kite, and several species of warbler, including a singing Eastern Bonelli’s Warbler in Northumberland.

The weather over the next few days will make it difficult for migrants to move. Strong winds and heavy rain is forecast to give way to light winds and warm weather for the latter part of the week and if this is the case we could see birds moving in force again – the spring is getting on and there will be a sense of urgency to get to the breeding grounds for these later arriving birds. More Spotted Flycatchers, Turtle Doves, Nightjars and House Martins should take advantage of any windows in the weather.

Scops Owl by Peter M Wilson

From mid-week we could see more overshoots but we are coming into the period where anything could turn up. An obliging Scop’s Owl would fit the bill, but given the Atlantic lows during the early part of the week maybe we should be looking to the west, we are overdue another Lark Sparrow.

Friday 2 May 2014

Look north and east this week

It has been an interesting week this week with a few what might have been expected southern overshoots. At least twelve different Hoopoes, a couple of Purple Herons and several Black-winged Stilts, along with several Wrynecks and Red-rumped Swallows but I’m not sure anyone would have predicted the superb male Cretzschmar’s Bunting that was found on Fair Isle, Shetland, or the Alpine Accentor that was found in North Norfolk, as late April birds.

Alpine Accentor by John Harding

The BTO satellite-tagged Cuckoos have begun to arrive back at their tagging sites. Skinner was the first, arriving back in Norfolk on 22 April but has since been followed by Chris, BB and Whortle. This is the culmination of a 4,000 mile, 3 month journey from Congo. Check them out here

Many of our migrants have now arrived in good numbers, particularly the warblers. Blackcaps and Whitethroats seem to be everywhere; well at least they do here in Norfolk. However, there does seem to be fewer Swallows, House Martins and Sand Martins around; perhaps they are being held up by poor weather further south. Northern Spain and southern France do seem to be getting more than their fair share of cool, wet weather this spring, or maybe the cold spring last year took more of a toll than was thought.

Singing Blackcap by Adrian Dancy

Swifts didn’t really arrive during the week but as high pressure moves in from the north the resulting light winds should be perfect for a mass arrival, and the east coast could be the place to be. On Sunday and Monday the high pressure will extend from Yorkshire to North Africa, so more southern overshoots can be expected. Rock Thrush is a classic early May bird, as is Red-footed Falcon.

Rock Thrush by Nick Moran

During the early part of next week, the northern part of Britain will be hit by a run of weather fronts that have crossed the Atlantic, so as May is one of the best months to see an American sparrow on this side of the Atlantic, White-throated Sparrow is on the cards, and probably on Shetland.