The rapid greening of the hawthorn leaves on hedgerows, surprisingly advanced for the third week of March, is starting to hide early nests delicately woven by Long-tailed Tits, Blackbirds and Dunnocks. It’s a reminder to put the hedge-trimmer back in the shed for the winter, and to leave part of the lawn uncut so that emerging insects can find pollen and nectar.

Chiffchaffs are now widespread in our woodlands, Sandwich Terns have been at several coastal watchpoints and Sand Martins are already exploring potential nest sites. The descending cadence of Willow Warblers, which used to be unusual in March, have been heard in several places, and six House Martins at RSPB Conwy last Friday were the first of the year in North Wales. Bird observatory wardens have returned to Bardsey, kicking off with a Firecrest on Sunday, among 219 migrating Goldcrests ringed on Sunday and Monday. They caught 177 Goldcrests all year in 2022!

Ring Ouzels are back on breeding territory in Nant Ffrancon and around Aber Falls, a few days after the first northbound bird stopped on the Great Orme. A pair of Garganeys were at RSPB Cors Ddyga on Sunday and an Alpine Swift was reported over Talacre on Wednesday. Several Ospreys have passed through the region; one caught a fish at Llyn Brenig on Sunday, but was not one of the breeding pair. Females have returned to nest sites on the Dyfi estuary and Llyn Clywedog, and those in North Wales should arrive in the next 10 days.

Winter birds are shipping out, but almost 50 Great Northern Divers in Caernarfon Bay, a regular stop for northbound migrants. Four Velvets Scoters and two Surf Scoters remain at Llanddulas, a Water Pipit was at RSPB Cors Ddyga, Twite at Gronant, Fieldfares on Mynydd Hiraethog, and Redwings and Bramblings over the Great Orme. In the Dee estuary, Hilbre Bird Observatory’s first Bearded Tit was a surprise last week and a Long-billed Dowitcher is at RSPB Burton Mere Wetlands.

[text updated on 28 March to reflect increased numbers of Goldcrests on Bardsey, and the return of two nesting Ospreys on the previous day]

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.

The wintry weather has paused the start of spring for some. Several Stonechats alongside the Conwy estuary on Saturday had perhaps been pushed downhill from nesting territories they had already established. In Bala, a flock of finches included 20 Bramblings, forced to take on extra food from a garden during spring migration to Scandinavia. The first Curlews were on territory in Mynydd Hiraethog last week but may have had second thoughts as the snow fell. This young Robin had probably left its nest several days prior to being photographed on the Prestatyn-Dyserth Walkway on 9 March. The egg from which it hatched would have been laid in early February.

Local readers have also seen Blackbirds carrying food to garden nest sites this week. Juvenile Crossbills in Clocaenog are less surprising since they time their breeding to the availability of pine seeds and so frequently nest in mid-winter. A Swallow at Felinheli, Sandwich Tern in Holyhead Bay and Garganey at RSPB Conwy are early returnees from Africa, while the first Wheatear and Sand Martins are in southern Wales.

The Baikal Teal remains at Foryd, near Caernarfon, Surf Scoters off Llanddulas, Snow Bunting at Kinmel Bay and five Ruddy Shelducks on the Clwyd estuary. A Black Redstart was near RAF Valley on Sunday, two Long-tailed Ducks off Llanddona and a dozen Twite at Gronant.

Bird Book of the Year, judged by the British Trust for Ornithology and British Birds, has been awarded to Low-carbon Birding, an anthology edited by Javier Caletrío. It shows how birdwatchers are responding to the climate and nature emergency by changing their behaviours. It is a timely decision to give the country's leading bird book prize to a work about how our interest affects the birds we love. The latest Sunday evening BBC nature blockbuster, fronted by Sir David Attenborough, highlights that Britain & Ireland can match wildlife anywhere on the planet. Coinciding with the series, WWF-UK, The National Trust and RSPB have kicked off a bilingual campaign to Save Our Wild Isles which calls on people to act for nature, and demand that business and political leaders do the same.

This week’s forecast Arctic blast of weather was prefaced by the appearance in central Anglesey of a duck from the east. A male Smew is on Cefni Reservoir, already providing a winter home to a Ring-necked Duck from North America. Smew visit from northern Scandinavia and Russia, where they nest in large holes, often made by a Black Woodpecker, in mature broad-leaved trees such as oak, willow and aspen.

The fortunes of these two ducks would astonish an ornithologist from a century ago. In recent years, the number of Ring-necked Ducks has increased and it is no longer considered a rarity by the Welsh Ornithological Society. Smew has become much rarer, however, as its winter range has contracted to the north and east, a phenomenon known as ‘short-stopping’. With climate change reducing the frequency of wintering waterbirds such as Bewick’s Swans here, expect fewer Smew to make it to Wales.

Sightings of adult male Smew are unusual – the last in North Wales was back in February 2006. While its English name is probably of Dutch origin, its Welsh name Lleian Wen (white nun) derives from the male’s appearance. Most Smew in Wales are ‘redheads’, a term used to describe females and males in their first winter.

Other waterbirds along our coast include Baikal Teal and Scaup at Foryd, near Caernarfon; Surf Scoters at Llanddulas and Benllech, and Long-tailed Duck and Black-throated Diver at the latter site. Four Slavonian Grebes are on Anglesey’s Inland Sea and another two were reported off Llanfairfechan at the weekend, where more than 120 Great Crested Grebes have gathered before they disperse to inland breeding lakes.

Chiffchaffs and Blackcaps seen recently may have overwintered here, but those showing traces of pollen around the base of the bill have probably arrived from the south, where spring is more advanced. A Swallow at RSPB Cors Ddyga on Sunday is the first of the year reported in North Wales. A Bearded Tit was reported from Gronant last week, the second record in the region in recent weeks.