GIVEN the sudden wintry weather at the beginning of October, it is not surprising that several bird visitors from northerly regions were recorded this week.
These included pink-footed geese, barnacle geese, Arctic terns, an Iceland gull, a juvenile Sabine’s gull, two little auks, a king eider, snow buntings and a Hornemann’s Arctic redpoll.
The Sabine’s gull was observed flying over Old Scatness on the 5th. This gull, a rare vagrant from the Arctic, winters off the coasts of south-western Africa and north-western South America, and is usually only seen inshore in Britain following strong winds.
The Hornemann’s Arctic redpoll, which is a large, pale race of Arctic redpoll from Greenland, and was found at Foula on the 1st.
The king eider is a male in eclipse plumage which has re-appeared in Clift Sound off Trondra. In eclipse, the male can be recognised by white patches on the forewings, a pale red bill and the triangular erect “sails” of the shoulder feathers.
King eiders are rare migrants from the Arctic, having a circum-polar breeding distribution. They winter along the coasts just south of their breeding areas and it is probable that birds arriving in Shetland come from wintering populations along the coast of Norway.
Individual king eiders appear in Shetland either from November to February or from late March to early June. Many have remained in Shetland for months or even years. The longest staying bird was in the West Mainland for over 11 years.
A red-throated pipit, a local rarity, was in the South Mainland on the 5th. In appearance, it resembles a meadow pipit in size and shape, but the upperparts are heavily streaked with black over a brown ground colour with pale-edged feathering. The adults have an orange-brown throat which is most prominent in adult males in breeding plumage.
Red-throated pipit is a rare migrant from northern Europe or Siberia, breeding mainly within the Arctic Circle, from Scandinavia through Siberia to Alaska. Migrating to winter in tropical Africa, it is probable that the strong south-east winds force this species west of its intended route. Most of the Scottish records are from islands with the largest number recorded on Fair Isle.
Other nationally rare migrants this week were the Blyth’s reed warbler and Pallas grasshopper warbler in Foula. The locally rare ring-necked duck and short-toed lark were also on the island.
A rustic bunting was at Loch of Voe, a marsh warbler at Quendale and the kingfisher was still at Sandwick on the 1st.
Notable other migrants included a spotted crake and a hawfinch (Quendale), a red-breasted flycatcher at Sandgarth in Voe, barred warblers at Hoswick and Kergord, grey wagtails and a siskin at Sandwick and yellow-browed warblers at a few locations.
There was also a marsh harrier, a sparrowhawk, a kestrel, bramblings and a bar-headed goose. This very pale grey goose has a white head with black cross-bars and yellow bill and legs. Bar-tailed geese are kept in captivity and frequently escape, although there may be some which breed in the wild in Britain now.
During the large influx of bird migrants in the second half of September, there were also several records of red admiral butterflies.
In Scalloway some gardens had four or five red admirals for several days. Red admirals are migrants to Britain from Europe, being able to fly powerfully for long distances. Arriving in May in southern Britain, they then breed, laying their eggs on stinging nettles. Their offspring move northwards, reaching Shetland a few weeks later.
There can also be another influx in autumn but there are also locally-bred butterflies. However, the appearance of so many red admirals, coinciding with the recent large fall in bird migrants, means that these late-flying individuals were probably migrants.