Migration Blog (11th – 17th September)

Although the weather over the last week was not conducive to producing large arrivals of commoner passage migrants from the near-continent, it didn’t mean there was a total lack of migrants to be seen across Britain and Ireland. With a predominately westerly airflow across much of the country the arrival of species such as Pink-footed Goose was to be expected and triple figure flocks of birds were seen at several sites. These birds are about 1–2 weeks ahead of the historical average, but follow the recent trend of arriving in early September rather than at the middle of the month. Could this be another example of how birds are responding to climate change?

Another winter visitor that was widely reported was Lapland Bunting. This smart-looking species was seen all the way from Unst, Shetland, in the north to Dorset in the south, with Fair Isle recording 27 birds on the 6th September. Could this be an indication of this being a good winter for this species? Let's hope so! It is worth learning the call of Lapland Bunting as this is often the best way of locating a bird. Areas of short open grass or ploughed field edges near the coast are prime habitat. They can often be found mixing with Skylarks. Siskin continued to be particularly evident over the last week. The BirdTrack reporting rate continued to increase with about 8% of complete list containing Siskin and several being noted over people's gardens in the early morning. 

Waders also continued to arrive. Curlew Sandpipers were well reported in small flocks mixed in with Dunlin and Little Stints at several sites. Also mixed in with these were the occasional scarce species, with Buff-breasted, Pectoral and Semipalmated Sandpipers being reported and giving a certain American flavour to proceedings. 

The westerly winds pushed seabirds closer to west-facing coasts and as a result several Leach's Petrels were reported. This diminutive seabird is a firm favourite of many birdwatchers and is always a good bird to see on any day. A few Sabine’s Gulls were also seen, some of which hung around to allow several people to catch up with this sought-after bird.

Rarity-wise the highlights from the past week include a Semipalmated Plover (the American cousin of Ringed Plover) in Orkney, a flock of 5 Blue-winged Teals on the Outer Hebrides, which is a UK record flock, and the reappearance of the Snowy Owl in Shetland.

Species Focus - Grey Wagtail

Many birds are on the move right now but when we think of migrant birds, Grey Wagtail might not immediately spring to mind. It is a partial migrant in the UK, in that some birds move – mostly those in the north – whilst others stay close to their breeding areas during the winter months.

Despite Grey Wagtail being a regular feature during autumn visible migration counts, sometimes in small flocks, little has been learnt in recent decades about their movements. Relatively few are ringed, adding the paucity of information. What we do know is that some Scottish and birds from northern England spend the winter in southwest England and in Ireland. A few of our Grey Wagtails have been found in France.

Considerable numbers of Grey Wagtails are recorded migrating across the Strait of Gibraltar into Morocco, and numbers build up in the winter in Algeria. It is currently thought that these are continental European birds, but it might be that some of our birds do this too and spend the winter in North Africa. A few also cross the Sahara and Grey Wagtail has been record wintering in Senegal. It could be that some of our birds do this too, but right now we just don’t know.

Grey Wagtail is encountered at coastal watchpoints throughout September and October. It is estimated that the UK has a breeding population of around 37,000 pairs and it is Red-Listed as a Bird of Conservation Concern due to a long-term decline; the breeding population fell by 40% between 1975 and 2017.

Whilst most migrating Grey Wagtail will be seen at coastal watchpoints, they can and do turn up anywhere, often spending a day or two around the edge of garden ponds, even in land-locked counties.

The week ahead looks like it could provide a wide range of species arriving from all points of the compass. No matter where you live, you should be able to witness migration at some level.  

Looking ahead

The weather for the weekend looks to be once again dominated by winds from a westerly direction. However, with winds being lighter and from a predominately southwesterly direction, this could result in birds on the move with some species happy to migrate into a gentle headwind. Siskin, Crossbill, Grey and Yellow Wagtail, Meadow and Tree Pipit, and Swallows and House Martins could all be recorded in relatively large numbers as they take advantage of the settled conditions and continue their southward migration. A fast-moving low from America could produce the autumn's first American passerines and there have been some big movements of species such as American Redstart recorded recently on the other side of the Atlantic. The Isles of Scilly are best placed for these, but they could turn up anywhere. Portland, for example, played host to a Yellow Warbler in 2017, as did Mizen Head, County Cork, in the same year. 

At the start of next week high pressure builds over Europe and drags in very warm air from the Mediterranean and North Africa. The associated settled winds should see several species heading south and visible migration will be the name of the game due to the lack of bad weather forcing birds to land. Visible migration is great, as you can witness it literally anywhere. Early morning is the best time to keep an eye on the sky. Flocks of Swallows and Martins could be joined by the odd Swift; these willl be a mixture of late breeding birds form Britain and Ireland and birds from Scandinavia. Finches will also feature in these movements and it is highly likely that Siskin will be the main species involved. Saying that, Chaffinch, Goldfinch and Crossbill also start to move at this time of year. The southerly winds may see some Mediterranean species turning up on our shores, with Red-rumpled Swallow, Woodchat Shrike, and Melodious and Subalpine Warbler all possible. 

Towards the end of next week the North East and Scotland should see easterly winds developing and producing a pulse of commoner migrants that have bred in Scandinavia. The main species to arrive will likely be Lesser Whitethroats, Willow and Garden Warbler, Redstart, Whinchat and Spotted Flycatcher. Amongst these will be the odd scarcity including Wryneck, Red-backed Shrike, Icterine, Greenish and Arctic Warbler, and possibly the first significant arrival of Red-breasted Flycatchers. We may even see an early Red-flanked Bluetail, which have had a record breeding season this year. Numbers of Short-eared Owls will increase over the coming weeks and any light winds or easterly breezes should see another arrival and could also invlove the odd Long-eared Owl. The coming weeks are also the peak time for Great Snipe and Citrine Wagtail, both of which will likely turn up given the easterly winds.

The southern half of Britain and Ireland will have south/south westerly winds. With these winds strengthening towards the end of the week, they could provide some interesting seabirds. As already seen in the past week, both Leach's Petrel and Sabine’s Gulls could be seen off southwestern coasts. This time of year also sees a late peak for Manx Shearwater, most likely involving this year's young that will be undertaking their first migration down to the seas off Argentina where they will spend the winter. Great Skuas also peak at this time of year. This brute of a bird can often be seen chasing gulls and Gannets offshore as they try to get them to regurgitate their last meal.