Isles secure first British record on type of sub-alpine warbler all set to be species in own right
A male subalpine warbler found at Skaw, Unst, by Rob Brookes on the first day of June subsequently turned out to be an even more interesting individual than at first thought. The subalpine warbler is a very smart bird, the males sporting blue-grey backs, brick-red underparts, noticeable orangey eye-rings, a striking white moustachial stripe and yellowish legs.
Originally thought to be of the race cantillans that breeds in southern Europe from Iberia east to Italy, this individual sounded more like a wren than a lesser whitethroat. Mike Pennington (to whom I am grateful for help with this) and others were alerted to its being of the subspecies known as Moltoni’s subalpine warbler that is found in the western Mediterranean islands of Corsica, Sardinia, the Balearics and Ligurian archipelago.
Its plumage of powder blue upperparts and less brick-red underparts also matches this race. Although on its own, it was seen at times to be apparently carrying nesting material into the spearmint in which it was usually found, but was last seen on the 11th. This will be the first acceptable British record of this subspecies which is likely eventually to be elevated to a separate species.
Other birds on the North Isles scene last week included a marsh warbler at Baltasound on the 10th, with several lesser whitethroats and chiffchaffs around north Unst. A spotted flycatcher was also seen at Norwick. This is always such a welcome bird to see as, according to the British Trust for Ornithology, this species has declined by 83 per cent since 1970.
Birds of prey included a kestrel at Funzie, Fetlar, and a sparrowhawk around Norwick. Funzie also hosted a female red-backed shrike in the area of the hide as well as a curlew-sandpiper. A passing sandwich tern was noted at Skaw, Unst, on the 10th. The first young eider ducks were seen at Haroldswick last Sunday when two females had four and two very small ducklings respectively.
A walk with visitors round Hermaness in near-perfect light on the 11th gave good views of breeding golden plover as well as wheatear, skylark and meadow pipit, the latter such an under-rated species. On the cliffs puffins were numerous and active, while common guillemots and a few razorbills could be seen both on land and the surrounding sea. Nearby, the first young gannets have hatched at the ever-growing colony.
A distant view of a pair of red-throated divers was supplemented a few days later when a pair flew past us at Funzie while we scoured the mires there for the red-necked phalarope. The only view, however, was of a female curiously resting on a stone where it had apparently been for some time, occasionally looking up. However, the so often elusive common snipes came up trumps landing in front of the hide, preening and bathing and displaying that fantastically cryptic plumage. A “rash” of heath spotted orchids on the island were a wonderful precursor to a visit to the Keen of Hamar, which gave up some of its secrets in spectacular fashion, with plenty of Edmondston’s chickweed in flower as well as northern rock-cress, mountain everlasting with its separate male and female flowers and a few late frog orchids. It is always a surprise to folk to find two colour forms of kidney vetch – the usual egg-yolk yellow of most, but the lemon yellow of a minority of flowers.
Good numbers of painted lady butterflies were still around last week. The most numerous moth in the Burrafirth trap has been the lychnis, a medium-sized greyish moth marked with white, whose larval foodplants are the ripening seeds of campions. Although widespread throughout Britain, it has only one generation north of the Midlands. Others have included garden carpet and dark brocade.