Changing day length triggers global journeys

Meadow Pipit (John Williams)

Garganeys and Wigeons at Porthmadog (Steve Culley)

Past the spring equinox, a mass movement of birds from the tropics and southern hemisphere is underway. Over the next eight weeks, hundreds of millions of birds will move north. The first Swallow and Garganey were in North Wales a fortnight ago, but more migrants arrived in the last week. The first Sand Martin was at Gronant last Wednesday and Wheatears on the Great Orme from Thursday, with more of each at numerous locations in the following days. Three Garganeys were on Glaslyn Marshes on Sunday and Swallows have been seen in Llandudno and Aber Dysynni. In Pembrokeshire on Sunday, Skokholm Bird Observatory noted its earliest Willow Warbler in almost a century of recording.

Birders on coastal headlands witnessed Meadow Pipits on passage, including a few that show peachy plumage. These orangey-washed birds may have unusually strong red pigmentation in their feathers, but seem to occur more frequently in western Britain during late March and April than elsewhere. But no-one knows whether they represent a discrete breeding population.

The standout migration event has been Alpine Swifts, a species that breeds no closer than the northern foothills of the Alps. They have been reported from more than 60 locations in Britain and Ireland in the last week, with multiple counts in many places, including nine over Bray in Co. Wicklow, visible from Anglesey in clear conditions, just 53 miles away. One was reported in Rhos-on-Sea last Thursday, but more may appear as these highly mobile birds attempt to relocate to central Europe.

Winter visitors will remain for a few weeks yet. Weekend sightings included Snow Buntings at Amlwch, Kinmel Bay and Gronant, where 21 Twite forage for seeds on saltmarsh plants, and an Iceland Gull at Moelfre. Two Slavonian Grebes in breeding plumage on the Alaw estuary will soon be heading north.

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