27 Sept 2022

From the edge of the world 2022 – part 7

Written by Craig Nisbet, Seabird and Marine Ranger, St Kilda

A small sandpiper bird perches on a rock by the edge of the sea. It has a very round body, with brown upper feathers and a white tummy. It has a very short tail and yellow legs.

A spotted sandpiper, only the second St Kilda record of this bird

With the seabird season nearing its end and autumn now upon us, we are eagerly awaiting the arrival of some rarer visitors. We track the movements of passage migrant birds locally and nationally, in the hope that we might be treated to a rare vagrant from distant corners of the globe.

Migration season on seabird islands is a period of excitement, anticipation and often frustration too. As we are situated so far west in the Atlantic Ocean, many of the drift migrants frequently recorded in the Northern Isles and down the east coast at this time of year don’t make it as far out as St Kilda. Coupled with that is the notable lack of vegetation cover for birds to roost in if they do make it here, apart from the many drystone structures and iris beds in the village.

However, we will often receive a smattering of more common species in spring and autumn. Although they normally breed elsewhere in the British Isles, they may be blown over in this direction by easterly winds. This was particularly clear in the first week of September, when a remarkable nine species of warbler were recorded within a 4-day period! All were common breeding species, except for the spritely yellow-browed warbler – this is a formerly rare but now increasingly common autumn migrant, particularly in northern and eastern parts of the UK. It’s thought that more westerly wintering grounds have been established in recent years, which is why through September this is now the most common warbler recorded in migration hotspots such as Fair Isle and Barra. Here on St Kilda, however, it remains a rarity, with this being only the 10th year that one has been recorded.

A small warbler bird stands in some grass, which is almost taller than it! Its feathers have a yellowish-green tinge, with black and white stripes on its wings. It has a black and white stripe by its eye.

Yellow-browed warbler

Another far-flung visitor to grace Hirta in early September was a North American wader that has been recorded increasingly frequently in recent years in the Western Isles. The buff-breasted sandpiper on Mullach Sgar was associating closely with a large passage flock of ringed plovers and was a real treat to discover, after anticipation of its arrival led to disappointment last season. A diminutive wader around the size of a dunlin, the sandpiper’s seasonality is such that most records will fall within a 2-week window between late August to early September.

A sandpiper walks through sand-coloured grass. It has a distinctive, scalloped brown and white pattern on its back, with a pale chest.

Buff-breasted sandpiper

There have been a couple more notable waders of a spotty persuasion so far this autumn, with a spotted redshank appearing on St Kilda in early September for the second consecutive year (after an absence of nearly 30 years since the first record in 1992). A second North American wader presented a tricky identification challenge when discovered on 18 September, but the conclusive record shots were enough to confirm St Kilda’s second record of a juvenile spotted sandpiper on the rocks in front of the Manse. The first record dates back to 1982 and this is one of only five previous occurrences of this species in the Western Isles. It’s these sorts of discoveries that really get the pulse racing when birding in remote locations during migration season!

A spotted redshank walks across green grass. It has long, bright orange legs and a long brown bill. It has an almost spotted brown plumage, which is darker on its back than on its belly.

The star of the season so far has to be the remarkable discovery of a harlequin duck in Village Bay on 23 August. The rare duck, more commonly encountered breeding in Icelandic or Canadian river systems or along nearby rocky coastlines in winter, was reported via Twitter, having been photographed by a visiting charter boat guide. St Kilda Ranger Sue Loughran managed to catch some better record shots of the duck the following day, as it busily fed close to the jetty. It was unfortunate that the duck didn’t linger for a few days longer, as I was on annual leave. There were birders elsewhere in the country who also would have been keen to make the long journey to see what is only the 16th British record for this species and the 2nd record for St Kilda, with the first occurring briefly in June 2007.

A black and white sea duck swims on the sea, past some little rocks poking out of the water.

Harlequin duck, only the second St Kilda record of this bird

This year sadly saw the departure of our long-staying snowy owl, fondly known as Snedge to the island community. She was found here in 2018 and apparently remained resident for four years, with occasional forays off to unknown locations. This summer, however, she has been positively identified on North Uist and most recently on South Uist in late August. Perhaps she’ll make the journey back over the water as winter approaches, or perhaps another snowy owl may turn up one day soon. St Kilda has a history of this species dropping in, so it certainly isn’t beyond the realms of possibility.

A snowy owl perches on some grass by some rocks. It has turned its head round so it is looking over its back.

Snedge the snowy owl in May this year

The stars of this year’s spring migration still remain fresh in our memory, with the 2nd St Kilda record of a little ringed plover, the 5th of a marsh warbler and the 6th of an osprey headlining a productive couple of months’ birding on the island.

A little ringed plover bird stands on some grass, with a rocky shore in the background. It has a brown back with a white tummy and a black 'mask'. It has a yellow ring around its black eye. It has long orange legs.

A little brown warbler bird perches on a rock beside a green leaf. It is looking up.

An osprey in flight, its wings spread wide, is silhouetted against a dusky blue sky.

Looking ahead to the end of October, with westerly winds forecast anything remains possible. The expected pulse of migrant thrushes, predominantly Icelandic redwings, will undoubtedly dominate the binoculars in October, but hopes are high for a rarer thrush, or perhaps even a North American warbler, displaced by seasonal weather systems in the mid-Atlantic. Living on a remote archipelago such as St Kilda presents many challenges, but the excitement of a migration season keeps any birder full of hope and anticipation.

Keep an eye on the St Kilda Rangers Twitter account (@StKildaRangers) in the coming weeks for regular bird-related updates and wish us luck in our search of the island!