Rare Bird Alert weekly round-up: 12 - 18 December 2012

The week's highlights:
Rose-breasted Grosbeak on the Isles of Scilly
Buff-bellied Pipit found in Berkshire
Hornemann’s Redpoll performs for all in Suffolk and another appears on Unst
White Gyr Falcons on Orkney and the Western Isles and in Derry
Pacific Diver reappears twice in Cornwall
American Coot still in Galway
Falcated Duck appears and disappears

This week saw a freezing start, with temperatures barely rising above zero on 12th and 13th. Temperatures rose dramatically on 14th, however, but this relief came with very strong south-east winds and driving rain. Conditions were particularly severe across northern Scotland. The remainder of the week settled down into a more typical December pattern with near-average temperatures and a weaker south-westerly airflow.

Headline birds
The totally unexpected highlight of the week came right at the end with the outstanding discovery on 18th of a Rose-breasted Grosbeak on St. Mary’s Isles of Scilly, found on a feeder near the dump. This is only the 23rd for Britain up to 2010 (with another 8 in Ireland) but is the 13th for the Isles of Scilly! Most remarkable, of course, is the date of this bird. Rose-breasted Grosbeaks are, almost without fail, October arrivals, the latest autumn discovery date at a west coast location being 30th October. Only two have ever been discovered later - on 5th November 1991 at Bridlington, Yorkshire and on 20th December 1975, at Leigh-on-Sea, Essex but both of these clearly made an earlier landfall somewhere else in Britain or Ireland. A December bird in the west is therefore utterly without precedent. With the autumn migration season so far behind, does this mean a near-certain ship-borne arrival?

The other highlight of the week was the discovery of a Buff-bellied Pipit at Queen Mother Reservoir, Berkshire on 12th, its identity confirmed on 13th and then remaining until 18th. Outstanding views were eventually enjoyed by most thanks to a cooperative sailing club and an effective day permit system.

This splendid find is of course a new bird for Berkshire and echoes the other inland reservoir bird, at Farmoor Reservoir, Oxfordshire on 8th to 10th October 2007, and the only other winter bird to date, at Wyberton, Lincolnshire from 5th December 2005 to 29th January 2006. As has been mentioned before, this species is becoming something of an autumn mainstay as well as a viable winter target too. With a breeding range as close as west Greenland, however, this is perhaps not too surprising. This area already provides us with Greenland Redpolls and some of our Lapland Buntings, not to mention all those Northern Wheatears.

Talking of Greenland and showy birds, another star bird of the week was the stunning Hornemann’s Redpoll, still on its sparse clumps of Yellow Horned Poppy along the top of Aldeburgh’s beach to 18th.

This, the second of the autumn in mainland England, must by now have delighted hundreds of visitors and become one of the most-photographed rarities ever. With its combination of extreme rarity, gorgeous appearance and ultra-close views, this must be a serious contender for ‘bird of the year’. While the bird at Holkham, Norfolk in October was for most of its stay both mobile and elusive, this bird can hardly have been more different, testing the close focus properties of binoculars, telescopes and cameras alike.

Interestingly, there can be no suggestion that the Holkham and Aldeburgh birds were one and the same. The former was a particularly heavily-narked specimen with a very rich copper wash to the head and breast, a rich brown mantle, liberal flank streaks and a narrow buff-suffused greater covert wing-bar. By contrast the Aldeburgh bird was a more text-book ‘snowball’ with a much weaker buff wash to the face, a whiter ground colour to the mantle, a broad white greater covert wing-bar and barely marked snowy-white flanks.

Surprisingly, another appeared again on Unst, Shetland on 17th, though whether this is one of the original birds from this autumn’s record-breaking influx or a new arrival is as yet unclear.

Although now a regular vagrant to Shetland and the Western Isles, it is worth reflecting on just how rare this species/form is in England. Unfortunately, the status of Hornemann’s Redpoll is not well documented but, even being generous, there can have been no more than eight previous English records and perhaps as few as four.

Even in their home range Hornemann’s Redpolls are not easy to catch up with. In Greenland they occur only in the northern half of the country. Even more remarkably, most spend the winter in Greenland too, only a tiny number appearing as vagrants south to Iceland, Scotland or mainland Canada. This is therefore a truly ‘must see’ bird, as special as a white Gyr Falcon or an Ivory Gull (the latter, by coincidence, also once seen on this very same beach!), and a bird which, like them, can only realistically be seen as a vagrant.

This species/form is not just so exciting because of its rarity, however. It also has an amazing lifestyle, living in conditions of extreme cold and darkness, and has therefore evolved the densest body plumage of any passerine. Snug behind its little concrete wall, the Suffolk bird must therefore hardly have noticed the freezing daytime temperatures of 12th and 13th. It is also likely that this bird had never seen people before. Perhaps it thought that its human observers were tight-ranked Musk Oxen, whilst those lying down were perhaps just funny seals. So, as well as being rare, beautiful and obliging, this bird also takes us on a real journey of the imagination - to the wild shorelines and shining ice of northern Greenland.

Also wanderers from remote parts of Greenland were this week’s White Gyr Falcons, the first at Deerness, Mainland Orkney on 13th, where it was seen feeding on a goose carcass, the second a repeat showing on 16th of the bird at Loch Paible, North Uist, Western Isles and then, amazingly, a different bird at Kilpheder and Orosay, South Uist on 17th and again on 18th. Finally, late news concerned yet another, at the Burnfoot River, Derry on 12th. After our Hornemann’s Redpolls, is there a realistic chance of one ever reaching south-east England? There has been a white bird in Holland so maybe, just maybe, this could happen!

Also perhaps from the same direction (albeit Canada rather than Greenland) was the returning adult Pacific Diver in Mount’s Bay, Cornwall, seen on 13th but then disappearing again until 16th. No doubt it will appear again though before the winter is out and, divers being long-lived birds, it presumably also has the potential to return for some winters yet.

Also from the Nearctic, but producing fewer gasps of aesthetic appreciation, was the lingering American Coot, still at Murloch, Galway on 18th.

Finally, a bird from another direction…. Last week’s gorgeous drake Falcated Duck at Farmoor Reservoir, Oxfordshire went missing (as did its Mallard companions) on 12th but was back again (with its friends) on 13th, only then to go missing again. Though some might baulk at Mallard as a carrier species, who knows how this bird might have got here. It won’t have flown non-stop from Siberia and would have mingled with a whole host of wildfowl along the way, so an arrival with an influx of Mallards is surely not an issue. Then again, it could of course be an escape. More importantly, perhaps, what a beautiful bird it was, its green and purple glosses and elegantly curved elongated scapulars straight out of a Chinese painting.

Western Palearctic News (or ‘Euronews’ if you prefer) was, as might be expected, a little sparse this week though the more adventurous successfully twitched Estonia’s Red Fox Sparrow. Otherwise, a Baikal Teal was in Switzerland, Rufous Turtle Doves were in Norway and Germany and a Black-throated Thrush was in Sweden on 15th.