Posted by Brydon Thomason on Sunday 2nd May 2010 | Birding in Shetland

These images were of the same (or presumed to be) taken in the exact same stretch of water last spring.

Two White-billed’s in one day!

Undoubtedly one of the most distinctive and stunning species of bird to visit our waters, White-billed Divers (or Yellow-billed Loon as they are also known) in summer plumage are simply exquisite.

Almost to the day, an annually returning adult in summer plumage passes through Bluemul Sound, (between Unst and Fetlar) presumably on its way North to its Arctic breeding grounds each spring – and today there it was! Pretty much on queue and in the exact same stretch of water I found the ‘diver’ today. In recent years any day between 25th April and 2nd May is a safe bet.

What was even more exciting was for me to discover another bird, some 15-20 mile South off Vidlin, (off a ferry) a pristine adult in summer plumage, with its bright almost glowingly neon- ivory bill, inc black upper parts topped with gleaning white and rather sequential white chequers on mantle – a sight that equals its status, rare!

White-billed diver breed in the High Arctic but their wintering grounds are something of an enigma amongst ornithologists. They are very rare visitors to British waters but in recent years are becoming more regular, so much so in fact that their status was downgraded from a ‘National rarity’ to a ‘Regional one’. Like the large majority of rarities from the Arctic, the North of Scotland, in particular the Western and Northern Isles very much host the lion’s share of records of this species.

Little, or in fact pretty much nothing is known of where these birds spend the winter. In recent years sightings of birds, such as the two I found today use the North of Scotland as a staging post on their way North to breed and so are either recorded as ‘fly by’s’ or just off shore for a day or two then they are gone. In recent years searching of rarely visited stretches of deeper waters has rewarded birders with multiple records, one of the main factors contributing to the changing of its status in Britain.

It is very likely that Britain hosts a much higher wintering number of these enigmatic seabirds than we may ever know, owing to their preference to much deeper off shore habitats than their commoner counterparts, Great-northern Divers.

Earlier in the month my close friend and ‘Shetland nature’ tourleader Micky Maher along with coleauges  found three of these stunning White-billed Divers, all in summer plumage in Argyll, Scotland. Micky also wrote the species account of White-billed Diver (during his time as Shetland Bird Club County Recorder) in the superb and highly acclaimed Birds of Scotland 3 which was published by the SOC  in 2007.

Along with the two records described above, two others have been found in Shetland waters in the past week, how many more are out there, the search continues…