Eastern Subalpine Warbler
Curruca cantillans (Pallas, 1764) (1, 1)
Photo © Kris Webb - Porth Hellick, St Mary’s, Isles of Scilly, 28 April 2020
STATUS
Polytypic, with two subspecies:
Curruca cantillans cantillans. Southern Italy and Sicily.
Curruca cantillans albistriata. Extreme north-east Italy, Balkans, Greece, and western Turkey.
OVERVIEW
Just two records in the period covered of this recently separated species.
RECORD
1). 1908 Fair Isle No locality, adult male, shot, 6th May, now at National Museums of Scotland (NMSZ 1908.94.17).
(W. E. Clarke, Annals of Scottish Natural History 1909: 72; Eds., British Birds 2: 422-423; Annals of Scottish Natural History 1909: 199; Clarke, 1912; Eds., British Birds 6: 151; Witherby, 1920-24; Baxter & Rintoul, 1953; Dymond, 1991; BOURC (2013), Ibis 156: 237).
History Wm. Eagle Clarke (1909) in the Annals of Scottish Natural History, Vol. XVIII. p. 72, says: 'The occurrence of this species at Fair Isle is one of the most interesting events of the year in the annals of British ornithology. That the second British specimen of this pretty little warbler should, like the first, have occurred in one of the most remote of our islands seems, on first thoughts, somewhat strange. It must be remembered, however, that in such places, should there be any one there to observe them, these waifs are more likely to be detected than elsewhere. If this bird has visited St. Kilda and Fair Isle it must surely have occurred elsewhere with us.'
In an Editorial (1909) in British Birds, Vol. II. pp. 422-423, they say: 'In the last issue of the Annals of Scottish Natural History (1909, pp. 69-75) Mr. W. Eagle Clarke gives a report on the observations made on this now well-known island during 1908.
The results are even more extraordinary than in previous years (cf. Vol. I. pp. 233 and 381), and this may be due to the fact that by the generosity of friends Mr. Clarke has been enabled to install a regular observer in the person of George Stout, a youthful inhabitant of the island, who had already shown himself an apt pupil. Beyond this important arrangement Mr. Clarke himself spent six weeks on the island in the autumn.
Mr. Clarke's report is this year confined to those species which are additions to the fauna of the island, and he tells us that a great mass of information is reserved for publication in a further contribution. In those occurrences which are referred to, however, there is a most unfortunate lack of detail, which greatly lessens their interest.
The list of Fair Island birds is now brought up to the remarkable total of 185.
We learn that Mr. Eagle Clarke has had the good fortune to secure the interest of the proprietor of the island in the investigations, and we understand that Mr. Clarke has now been granted the sole right to shoot on the island. The following is a brief summary of the most notable items: - Subalpine Warbler (Sylvia subalpina). - This is one of the most interesting of these remarkable records, but only the bare fact that a bird of this species occurred during the year is chronicled. It will be remembered that the only other known occurrence of this species was at St. Kilda on June 13th and 14th, 1894 (cf. Saunders' Manual, p. 53). Now that Dr. Hartert has distinguished between the various races of this species (Vog. Pal. Fauna, pp. 596-7), it would be interesting to discover the region of the origin of this specimen (we presume the bird was secured) by a careful comparison.'
Clarke (1912 (2): 66) under 'A Year at Fair Isle' in George Stout's diary of 1908, says: 'Newcomers noted are an adult male Subalpine Warbler on 6th May.'
In an Editorial (1912) in British Birds, Vol. VI. p. 152, under 'Additional records for Fair Isle and St Kilda', they say: 'In his Studies in Bird-migration, Mr. Eagle Clarke gives a good deal of hitherto unpublished information about the rarities observed in Fair Isle and St. Kilda, and a few new facts about those in the Flannans and Sule Skerry. The most important additions thus made to the details given in our Hand-List of British Birds are as follows: - Fair Isle: The bird was an adult male, and was obtained on May 6th.'
1950-57 RECORD
2). 1951 Fair Isle Smirri Geo, adult male, 20th to 27th May, trapped 24th May, S. c. albistriata.
(K. Williamson, Fair Isle Bird Observatory Bulletin 1 (2): 26-28; K. Williamson, British Birds 45: 260-261; BOU, 1971; Thom, 1986; Pennington et al., 2004; Forrester & Andrews et al., 2007).
History K. Williamson (1952) in British Birds, Vol. XLV. pp. 260-261, says: 'A feature of the spring, 1951, migration at Fair Isle was the capture of two adult male Subalpine Warblers (Sylvia cantillans), the seventh and eighth records of the species in the British Isles. An account of the trapping of these two birds was given in Fair Isle Bird Observatory Bulletin, Nos. 2 and 3, 1951, but it may be of interest to publish the main points here, together with a note on the meteorological conditions prevailing at the time.
The first bird arrived on May 20th and remained until 27th. It was first seen by Philip Andrews, one of the observers then staying at the hostel, among some derelict rusty iron girders on a sheltered beach close to the South Lighthouse. It was obviously very tired, and sat in the sun with ruffled plumage and half-closed eyes. It was much more active on subsequent days, seeking insects on the lichen-covered slabs of a cliff near by, often in close proximity to other small warblers.
Periodically it returned to the beach and sought the warmth and shelter of the rusty girders where it had been first seen, sometimes feeding industriously on the Chironomid gnats which were attracted by the upcurrent of warm air from the iron-work.
A makeshift trap, consisting of the Yeoman Net closed at one end with a catching-box, was set in position over the girders on 22nd, and next morning Andrews, Max Budgen and H. A. Craw succeeded in catching the bird.
Plumage. It had a Nuthatch-grey head and back, brown and abraded wing-feathers, a rich dark chestnut breast, and a delicate pinkish-buff suffusion on the sides of belly and flanks. The chestnut was in the form of a "bib" whose margin was clearly defined, not merging with the pinkish-buff below. The tail was darker than the back, blackish-brown except for the outermost feathers, which were paler and had the outer webs and part of the inner webs white. There was some white on the tips of the penultimate pair. The rump was a cleaner blue-grey than the mantle. There were pale brown fringes on the tertials only, and whitish tips to the tertials and inner secondaries. The most striking features were the clear white moustachial streaks separating the chestnut and grey, and the startling red rims which encircled the eyes - "eyes like a miniature Oyster-catcher", as one observer remarked. After examination the bird was set free at the place of capture, where it remained, usually haunting the lichen-covered cliff, until the 27th. When in the laboratory it made a noise very like the "churr" of a Lesser Whitethroat (Sylvia curruca), but on the beach the only call it was heard to utter, and that infrequently, was a hard "chep".
It was examined in the lab. and watched in the field by R. Shepherd, Philip Perkins, R. E. Sharland, D. V. Freshwater, A. Colin Russell and Dr. R. G. Mayall in addition to the writer and those already named above.
The Weather. Examination of the Daily Weather Reports of the Meteorological Office, London, suggests that both birds reached the British area from the north of Italy rather than from the Iberian Peninsula or South of France. The first may have travelled via a col between two high pressure systems, as already described elsewhere (p. 248). There were more arrivals at Fair Isle on the 20th, during the day, than on any other date in spring, and they included Lesser Whitethroats (which reached their peak with over 50 birds), Common Whitethroats (building up to peak on 21st), a male Blue-headed (Motacilla f. flava) and three female flava wagtails, and three male Red-spotted Bluethroats (Luscinia s. svecica). Somewhat similar conditions obtained during June 7-8th, although in this case neither of the anti-cyclones was so extensive. A shallow low covered France and western Germany, and there was again a S.E. airstream from the north of Italy through central Germany, backing easterly in Denmark and the Netherlands and the North Sea area. It is possible that the continuance of anticyclonic weather, with light winds favourable to migration, failed to inhibit the urge to migrate when the breeding-area was reached, causing the birds to overshoot their normal range and drift N.W. across the Continent between the two highs.'
Comment The second individual is recorded under Subalpine Warbler sp.
