Fast-moving Atlantic low-pressure systems in the autumn trigger expectation among west-coast birders hoping to find a North American songbird. Most storms occur in October, when the majority of southbound migrants are already well out of the way, but ex-hurricane Lee last week deposited an unprecedented number of vagrants into Britain & Ireland. Hundreds of birds probably made landfall, most never to be found in remote coastal areas, but of those that were, Wales was the focus for some of the rarest.

Pembrokeshire kicked off last Wednesday with Wales’ first Alder Flycatcher on Skokholm and first Magnolia Warbler on St Govan’s Head. On Thursday, Wales’ fourth Bobolink was found on Skokholm, first Bay-breasted Warbler on Ramsey and a Red-eyed Vireo near Porthcawl. North Wales joined the party with Wales’ second Black-and-white Warbler found by ringers on Bardsey. Friday brought Wales’ first Cliff Swallow to Sker Point and another Bobolink was reported in the Vale of Glamorgan. Remarkably, young Chester-based birder, Toby Phelps, who found the Magnolia Warbler, only the third ever in Britain, surpassed that on Saturday morning with Britain’s first Canada Warbler at nearby Flimston. Saturday brought a second Black-and-white Warbler to Bardsey, now the only two ever to be ringed in Europe and another Cliff Swallow found by birders visiting Ramsey. Sunday saw, incredibly, a second Magnolia Warbler, this time at Briton Ferry near Port Talbot, but bad weather frustrated clinching the identification of an American flycatcher at Pen Cilan, near Porth Neigwl. 1 in 6 of the North American songbirds ever recorded in Wales arrived last week, and there may be more to find, with more storms forecast from Wednesday.

In four days, five species never previously recorded in Wales have been seen. For context, the average number of new species added to the Welsh List each decade since 1900 is 14, so last week was genuinely unprecedented.
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Lost migrants, by their nature, fail to add their genes to native populations but Dr Alexander Lees, Reader at Manchester Metropolitan University and co-author of Vagrancy in Birds, warns that climate change could magnify the impact of such events: “tens, maybe hundreds of thousands of migrant birds, will have drowned in the Atlantic before a few make European landfall. Increasing storm severity will lead to a temporary increase in vagrants, but in the longer-term population size could be affected”.

Last week BirdNotes reported on the dramatic threats to Britain’s seabirds from warming seas, and North Wales Wildlife Trust reported that 40% of Arctic Terns and 55% of Sandwich Terns at its Cemlyn colony on Anglesey were lost to avian flu, so news of a seabird success story is very welcome. Denbighshire County Council announced that a record 212 pairs of Little Tern bred on the beach at Gronant, fledging 155 youngsters. Another 16 fledged at the RSPB Point of Ayr colony, established in 2019, and hopefully most are on their way to their first winter in West Africa.

The Gronant colony is at its largest in almost 50 years and produced exactly the right number of chicks this year to maintain its size, an average of 0.74 young per nest. It constitutes 10% of the UK Little Tern population, thanks to sterling work by local authority wardens and volunteers from North Wales Little Tern Group who use fences and daily patrols to protect the beach-nesting seabirds from predation, and disturbance by people and dogs. The birds are one of the species for which government has to manage the Liverpool Bay Special Protection Area, which extends from eastern Anglesey to north Lancashire.

A Yellow-browed Warbler near Carmel Head last Wednesday is the earliest ever found in Wales. Most arrive in early October. Curlew Sandpipers are passing through North Wales, including 10 on the Border Pool at RSPB Burton Mere Wetlands, which also hosted a Pectoral Sandpiper, a couple of Wood Sandpipers and 12 Cattle Egrets. Four Curlew Sandpipers and a Pectoral Sandpiper were on Anglesey’s Alaw estuary. Other highlights include a Hoopoe in an Aberffraw garden, Sabine’s Gull off Point Lynas and Bull Bay, and a Cory’s Shearwater past Bardsey. A Little Stint is at RSPB Conwy, the first Lapland Bunting of autumn at RSPB South Stack and a Hooded Crow was reported at Llandudno’s West Shore.

I’m looking forward to speaking at the Welsh Ornithological Society’s conference at Aberystwyth University on 4 November, and hope to meet birdwatchers from across North Wales. Also speaking on the theme of "Into and Out of the Red – creating a brighter future for birds in Wales" will be WOS President, Iolo Williams, the BTO’s Rachel Taylor, NRW’s Patrick Lindley, Rare Breeding Bird Panel chair Dawn Balmer, and Bob Haycock from Pembrokeshire Bird Group. Full details and how to book are on the WOS website.

​Seabirds are tough. They deal with severe weather annually, but the last two years in northwest Europe illustrate that a changing environment can be too much even for them. Birders were thrilled to see thousands of Cory’s Shearwaters, which breed on the holiday isles off southwest Europe, move into the Southwestern Approaches and Celtic Seas. Rare tropical seabirds have been spotted, such as Red-footed Booby on Scilly and Brown Boobies as far north as Scotland, and even in the Baltic near Helsinki. But the unprecedented spectacle should worry us.

Globally, July and August were the two warmest months ever, August sea temperatures smashed records and an early summer marine heatwave saw waters around Britain up to 5°Celsius above the norm. Such big changes could have shifted the food web and left Guillemots and Razorbills struggling to find food before they head into the Atlantic for winter. Many washed up dead on beaches last month, but tested negative for avian influenza.

Yet bird flu has taken a huge toll on breeding seabirds, such as terns on Anglesey and Deeside, and Gannets in Pembrokeshire. RSPB Cymru reports that only 16,482 pairs of Gannets nested on the island of Grassholm this year, down from 34,491 pairs in 2022. The 52% reduction has set the population back more than 50 years to 1969 levels.

On land, more than a dozen Wrynecks were found in Pembrokeshire during last week’s heatwave. One made it to Bardsey, where it was still present on Monday. Small groups of Curlew Sandpipers are on the Alaw and Cefni estuaries, a Spoonbill on the Clwyd and a Dotterel was on coastal heath near Rhoscolyn. Ruffs are moving through the region, Great White Egrets are on Llyn Trawsfynydd and Llyn Traffwll, and a Black Kite was an excellent record for Bardsey.

September is a critical month for many trans-Saharan migrants, which need to be in good condition for the long journeys ahead. Although in less of a rush than in spring, they rely on a habitat network from northern Europe to West Africa at which they can rest and refuel. Species that I have too easily taken for granted through the summer, such as Reed and Sedge Warblers, Whitethroats and Garden Warblers, were busy feeding as I made a circuit of RSPB Conwy. Most go about their business quietly, but some Chiffchaffs have started their disyllabic song as though it were spring. Many will not leave here until late September and travel only as far as the Atlantic seaboard of Iberia and Morocco. There appears no definitive answer as to why some Chiffchaffs sing before departure when most birds are silent. Are these our breeding birds, or migrants from farther north. Who knows?

Cattle Egret numbers have increased rapidly in Britain this century; at least 60 pairs now breed in England. Smaller than Little Egrets, 20 years ahead in their colonisation and with a year-round bright yellow bill, a flock of at least 28 were on the Dyfi estuary on Sunday. Found initially at Ynys las nature reserve in Ceredigion, they were later seen on saltmarsh on the Meirionnydd side. It is by far the largest group of Cattle Egrets seen in Wales, and for context, only 28 were recorded in Wales between the first in 1980 and the end of 2009.

A dozen Little Gulls were dip-feeding in calm waters at Point Lynas, while others saw Sabine’s Gull, Long-tailed Skua and Black Terns there over the weekend. Garganey and Wood Sandpiper were at RSPB Cors Ddyga, another Garganey at RSPB Valley Wetlands, and Firecrest and Merlin on Bardsey.

Work started this week to rejuvenate the Reception Pool at RSPB Burton Mere Wetlands. Periodically resetting the ecological clock is an essential wetland management tool, alongside water level control and grazing management, performed there by Carneddau ponies. As well as improving the diversity of the habitat, the work will enhance views for visitors over the coming years. Read more about the work here.

Edited 5 September to clarify that the flock of Cattle Egrets was found initially in Ceredigion before moving onto the Meirionnydd bank of the Dyfi estuary.