A visit to a seabird colony should be a memorable experience, an immersion in one of the wonders of the natural world. Britain’s seabird cliffs and islands are of global significance, and Wales alone holds half of all the Manx Shearwaters on the planet. But for experts monitoring seabirds this summer, it’s a worrying time. Images of sick and dying Great Skuas on Scottish islands were followed by hundreds of dead birds, including Eider ducks and Pink-footed Geese, on the Sutherland coast, and now ornithologists visiting a Gannet colony at Hermaness, Shetland, have shared photographs of dozens of dead birds, their carcasses picked over by scavengers such as Great Skuas and gulls. Last winter, up to one-third of the Svalbard Barnacle Goose population is estimated to have died of highly pathogenic avian influenza (HPAI) on the Solway Firth.

Wardens and ornithologists at Welsh seabird colonies such as South Stack, the Skerries and Ynys Seiriol/Puffin Island are keeping a close eye on the health of seabirds such as Kittiwakes, Guillemots and terns, while in Pembrokeshire checks are being made on one of the world’s largest Gannet colonies, on Grassholm. Seabirds are already under pressure from human activities including climate change, rat infestations, recreational disturbance and construction developments at sea, and the United Nations has declared that wild birds are the victims of HPAI viruses. The virus has already had devastating consequences for some poultry farms and, according to some reports, reduced by 40% the number of gamebirds released this summer following outbreaks in France, where many Pheasants and Partridges are bred.

It’s a critical time for seabirds, with the first Sandwich Terns at Cemlyn ready to hatch their eggs this week and a pair of Mediterranean Gulls incubating a clutch there. At Gronant, wardens are appealing for public help to stay away from the nesting colony of Little Terns and for more volunteers to help protect the birds.

Unusual sightings this week include Little Gulls off the Great Orme and Cemlyn, six Mediterranean Gulls on Porthmadog’s Llyn Bach, three Spoonbills reported near Rhyl and two Siberian Chiffchaffs singing on Bardsey, although a rarer visitor was the first Jay on the island for more than 28 years. The week has seen three Osprey chicks hatch at Glaslyn, bringing the total hatched by female ‘Mrs G’ to 52 since she first nested there in 2004. Osprey nests on the Dyfi estuary and Clywedog Reservoir also have three chicks.

The rush of spring migration is over, and most birds are concentrating on pairing up and nesting. The second half of May can spring surprises though. Warm southerly winds last week resulted in several Mediterranean migrants ‘overshooting’ to Britain. A Golden Oriole was a great find on Bardsey last week, and a Bee-eater over RSPB South Stack on Saturday would have attracted more attention had it not continued out to sea. Hobbies and Spotted Flycatchers are still arriving in North Wales from the south, while to the south a Dark-eyed Junco, Moltoni’s Warbler and Woodchat Shrike have been seen in Pembrokeshire.

Small numbers of waders are still moving north, with Little Stints on the Alaw estuary, Cemlyn and Traeth Cymyran at the weekend, with small flocks of Sanderlings. A Curlew Sandpiper was among a large flock of Dunlins on the Alaw estuary too. The Iceland Gull that wintered on the Little Orme remains in the area, favouring the rocks below Great Orme’s former lighthouse. Hooded Crows have been at RSPB South Stack, the Great Orme and Tregele. A Little Gull and two Mediterranean Gulls have been on Llyn Bach, near Porthmadog, and a Whooper Swan on nearby Pwll McAlpine may not have been strong enough to make the return migration to Iceland.

Birds are not the only migrants on the move. The southerly airflow has enabled good numbers of migratory moths and butterflies to arrive in Britain this week. Painted Lady butterflies, dark orange with black-and-white striped wingtips, are among the most obvious, their ‘journey’ having begun several generations ago in North Africa. Moth enthusiasts have also enjoyed day-flying Hummingbird Hawkmoths and nocturnal Striped Hawkmoths. With an 8 cm wingspan, they love feeding around Red Valerian, a common plant in North Wales. More than 100 Striped Hawkmoths have been reported on Twitter in the last week, according to @MigrantMothUK, the majority in southern England. But one found on Bardsey shows that they could turn up anywhere, and some may lay eggs here on bedstraw and dock plants.

I wasn’t the only one to exclaim “they’re back!” to no-one in particular last week. Through the open window came the scream of Swifts over the village rooftops. My partner teases me for my enthusiasm about their return, but knowing the dramatic decline in their numbers across Britain in recent years, I can no longer take their arrival as a certainty. And from comments on social media, I know that I'm not the only one to celebrate their return. As Blur once wrote about feeding sparrows, the Swifts' arrival gives me a sense of enormous well-being.

I heard Swifts over Llanberis and Penmaenmawr too, and witnessed a pair mating as they flew low over my house at the weekend. Their tiny feet had not touched anything solid since they left the edge of their nest cup last summer and headed to the humid air above the forests of central Africa. North Wales Wildlife Trust has installed over 500 nestboxes on buildings around the region since 2014, and another 80 have been put up in the Dyfi Biosphere Reserve this winter by the Machynlleth Climate Action Group. Read more about what local people are doing for Swifts in this article written for The Daily Post.

Another welcome spring sound, that of the Cuckoo, has rung across the hillsides in recent weeks. One, called Daniel that was tagged by the British Trust for Ornithology last June, has returned to RSPB Lake Vyrnwy after spending autumn in Chad and winter in Cameroon. After weeks of satellite silence, he popped up in Sicily in late April before arriving back in mid Wales via central France. Follow his travels on the BTO website.

A third pair of Ospreys has set up home in Nant Glaslyn near Porthmadog. In addition to the long-standing site used annually since 2004, a second nest had been occupied there in 2021 by a female released in Dorset’s Poole Harbour in 2018 and a male hatched on the Dyfi estuary in 2017. Now another Scottish female translocated to Poole Harbour in 2019 has set up home with a Dyfi fledgling from 2018. More details on the Birds of Poole Harbour website.

Most migrants are already on their breeding territories, and the last to arrive – Spotted Flycatchers – arrived in a rush from Monday, with a dozen on the Great Orme and almost 80 on Bardsey on a single day. A Hen Harrier over Bardsey on Saturday was unseasonal and a Short-eared Owl rested briefly on the Great Orme last week.

Two sites in North Wales have upheld their deserved reputation as among the best in Britain for scarce wagtails. RSPB Conwy scored first, with a Yellow Wagtail of the Iberian race found on Friday and relocated on Sunday. It is the first ever seen in Wales, although the nature reserve had a ‘near miss’ in April 2008 when a likely candidate was seen, but it proved impossible to record its call to clinch the identification. No such problem this time, with more birders carrying recording equipment and this week’s bird more vocal.

On Sunday, a possible Citrine Wagtail heard near Cemlyn lagoon on Anglesey was confirmed by a sighting in a nearby field. The bird remained all day, alongside a Blue-headed Yellow Wagtail. It’s only the 10th Citrine Wagtail in North Wales, a bird that breeds no closer than the Finnish border with Russia. By coincidence, the first Citrine Wagtail in North Wales was at RSPB Conwy in April 2008, found when I went looking for that putative ‘Iberian Wagtail’.

Now is the time to visit our broad-leaved woodlands, as the fresh leaves of Oak and Beech unfurl. For places to visit, check the excellent Celtic Rainforest Wales website. The project is doing great work to restore these sites by removing invasive Rhododendron and reintroducing grazing by ponies and cattle. Listen for Redstarts, Pied Flycatchers and Wood Warblers that recently arrived from Africa. The first two species nest in holes, but Wood Warblers nest in foliage on the ground, which is another reason to keep dogs on a lead in the countryside this spring.

Good numbers of Swallows finally arrived this week, with smaller numbers of House Martins and Swifts. Hooded Crows were on the Great Orme, Clwyd estuary, Bardsey and RSPB South Stack, while three Dotterels were on the summit of Foel Fras on Sunday. Two Avocets spent last Wednesday on the Conwy estuary, but didn’t linger.

The curious sight of the back end of a Chough wiggling above the grass, its head buried deep into a Rabbit hole, indicates the tough times that birds are having. The rabbit burrows on the Great Orme provide the Choughs with access to more moist and less compacted soil than on the surface, into which they can probe for invertebrates. Swallows and House Martins, now finally arriving in North Wales, will need wet mud with which to build their nests, but puddles are hard to find after an April that saw Wales receive less than half its average monthly rainfall. As any farmer can attest, the region’s grasslands that are home to our last remaining Curlews and Lapwings are dry, and will these hold enough insects for wader chicks to forage in the coming weeks?

With no substantial rain forecast, garden owners can help their local birds by providing a shallow bowl of water for birds to drink and bathe, and I know farmers who ensure there are puddles in the muddy corner of farmyards that Swallows can use. For the Choughs and waders, we have to hope for rain – but, then again, not so much that it washes the caterpillars out of woodlands just as the Pied Flycatchers hatch.

We are hitting the peak of spring migration, and last week saw a second wave of Ring Ouzels and Wheatears. ‘Our’ birds are already holding territories in the mountains, where some have already hatched their first chicks, but along the coast are birds that will head farther north: the Wheatears to Iceland, Greenland and even northeast Canada, and the Ring Ouzels to Scotland or Scandinavia. Up to half a dozen Ring Ouzels and two dozen Wheatears have been on the Great Orme each morning.

Rarity of the week is a Pectoral Sandpiper, a wader en route to its Arctic Russian breeding grounds but pausing in the southeast corner of Llyn Trawsfynydd, where an Osprey has been fishing regularly. The first Swifts and Spotted Flycatchers have been seen across North Wales in recent days and a Wood Sandpiper was at RSPB Cors Ddyga over the weekend. A Nightingale sang on Bardsey last week, the island had its first ever spring record of a Black Tern, and a 32-year old Manx Shearwater was caught and released. It had been ringed there in August 1989 and had not been handled since August 2000, two days before ringer and assistant warden Ed Betteridge was born!