Blyth's Reed Warbler

Acrocephalidae

Jun 3

Acrocephalus dumetorum Blyth, 1849 (10, 0)

Photo © Phil Woollen - Hilbre Island, Cheshire & Wirral, 5 June 2011

Ex BBRC species 31/12/2014

STATUS

Palearctic. Monotypic.

OVERVIEW

Witherby's record from 1912 on Holy Island was an atypical individual and probably warrants a closer inspection of the details.

Records as per BOU (1971).

RECORDS

1). 1910 Fair Isle No locality, shot, 29th to 30th September, now at National Museums of Scotland (NMSZ 1988.52).

(W. E. Clarke, Annals of Scottish Natural History 1911: 70-71; Eds., British Birds 4: 362-363; L. J. Rintoul & E. V. Baxter, Annals of Scottish Natural History 1911: 135; Clarke, 1912; BOU, 1915; Bedford, 1937).

History Wm. Eagle Clarke (1911) in the Annals of Scottish Natural History, Vol. XX. pp. 70-71, says: 'In September last, a small plain-coloured bird resembling a Garden Warbler in colour was observed by Her Grace the Duchess of Bedford in a small plot of turnips at Fair Isle. It was very shy, and only afforded a momentary view ere it sought fresh cover. It was found by observer in the same place on the following day, and after some trouble was secured, and believed by its captor to be a Reed Warbler. On receiving the skin I found that it was not a specimen of the common Reed Warbler, and on further examination along with Dr. C. B. Ticehurst we made it out to be Acrocephalus dumetorum. Not having any specimens of this species with which to compare it, I sent the bird to Dr. Hartert, who kindly confirmed the identification. Blyth's Reed Warbler is not only an addition to the British avifauna, but is a new bird for Western Europe, for it has not, I believe, been found farther west than Russia....In colour it more resembles the Marsh Warbler (A. palustris) than the Reed Warbler (A. streperus), but is a little duller in colour and usually smaller in size, though the smallest Marsh Warbler and the largest dumetorum overlap. The wing-formula of Blyth's bird differs from both the British species just mentioned in having the second primary shorter than the fifth.'

In an Editorial (1911) in British Birds, Vol. IV. pp. 362-363, they say: 'Yet another bird is added to the British list by the indefatigable workers on Fair Isle. Mr. W. Eagle Clarke records (Ann. Scot. Nat. Hist., 1911, p. 70) that a bird somewhat like a Garden Warbler was observed in some turnips on Fair Isle by the Duchess of Bedford in September, 1910, but only a momentary view of it could be obtained. On the day following (no exact date is mentioned) the bird was found in the same place, and obtained by Mr. Clarke's observer.

Mr. Clarke and Dr. C. B. Ticehurst identified it as Blyth's Reed Warbler (Acrocephalus dumetorum) and this has been confirmed by Dr. E. Hartert. The coloration of Blyth's Reed-Warbler is less red than that of the Reed Warbler, and even slightly more olivaceous and rather darker than that of the Marsh Warbler, but to distinguish any of these three species by the coloration without very careful comparison is impossible.

Blyth's Reed Warbler, however, differs in wing-formula from both the other species, by having a considerably shorter second primary. This in Blyth's Reed Warbler falls between the fifth and seventh (and is sometimes shorter than the seventh), whereas, in the other two species, the second is generally equal to the fourth.

According to Dr. Hartert (Vog. Pal. Fauna, I. p. 564) Blyth's Reed Warbler breeds in the Himalayas, Altai, Turkestan, Bokhara, Transcaspia, western Siberia, and in Russia from Orenburg to Moscow and St. Petersburg, and northward to Archangel. It winters in India, southward to Ceylon and Lower Burma. It does not appear to have been noticed previously westward of St. Petersburg.'

Admitted by L. J. Rintoul & E. V. Baxter (1911) in the Annals of Scottish Natural History, Vol. XX. p. 135, under 'Report on Scottish Ornithology in 1910.'

Clarke (1912 (2): 135) under 'The Birds of Fair Isle', says: 'Blyth's Reed Warbler. On the 29th of September 1910, a small Warbler was found by the Duchess of Bedford in a patch of turnips. It only afforded a very brief view ere it flew off. It was present in the same cover on the following day, and then aroused suspicion that it might perhaps be something uncommon. After a great hunt it was secured, and sent to me.

In colour it more resembles the Marsh Warbler (A. palustris) than the Reed-Warbler (A. streperus) but is a little duller in colour and usually smaller in size, though the smallest Marsh-Warbler and the largest dumetorum overlap. The wing formula of Blyth's bird differs from both the British species just mentioned in having the second primary shorter than the fifth.

Blyth's Reed-Warbler is a new bird for Western Europe, not having previously, I believe, been found nearer than Russia. It is a summer visitor to regions from St Petersburg and Archangel eastwards to the Yenisei (Western Siberia), and the Himalayas (Kashmir to Nepal); and winters in the plains of India, in Ceylon, and from Sind to Assam.'

Mary, Duchess of Bedford (1937: 27) says: 'The year 1911 has to begin with a rather melancholy record of a lost opportunity in the past. When walking through a patch of turnips on Fair Isle in September, I put up a bird which I thought might be a Garden Warbler, but as I was not sure, I tried to find it again. Shortly after, Stewart Stout and J. Wilson walked through the same piece of turnips, and I saw them flush the same bird. Stewart called out to me, "Garden Warbler".

The following morning they found it again in the same turnips and shot it. In the evening, Stewart showed it to me as a Reed Warbler. It seemed to me to be too yellow on the underparts and not sufficiently red-brown on the back for that bird, but as Stewart was much more accustomed to handling skins of small birds than I, I deferred to his opinion, only remarking that it was not like the Reed Warblers that I knew, but possibly their plumage was different in autumn.

The skin has now been identified by Mr. Eagle Clarke and Mr. Hartert as Blyth's Reed Warbler, Acrocephalus dumetorum - the first occurrence in Great Britain.'

Admitted nationally in their second List of British Birds (BOU 1915).

2). 1912 Yorkshire Spurn, obtained, 20th September.

(J. K. Stanford, British Birds 6: 217; W. R. Ogilvie-Grant, Bulletin of the British Ornithologists' Club 34: 271; Witherby, 1920-24; Chislett, 1952; Mather, 1986).

History J. K. Stanford (1912) in British Birds, Vol. VI. p. 217, says: 'On September 20th, 1912, I obtained an example of Blyth's Reed Warbler. It was very tame, and I watched it for some time feeding in a patch of sea-buckthorn. The wind had been north-east for several days, and the only other birds about at the time were a few Redstarts and Common Whitethroats; a Spotted Flycatcher (Muscicapa s. striata) also appeared on the 20th. I am most grateful to Dr. N. F. Ticehurst and to Dr. E. Hartert for the trouble they took in identifying this bird.'

W. R. Ogilvie-Grant, Editor (1914) in the Bulletin of the British Ornithologists' Club, Vol. XXXIV. p. 271, on the unexpected occurrences for 1912, says: 'Single birds shot Spurn Head (Yorkshire), September 20th.'

Accepted locally (Chislett 1952: 96; Mather 1986).

3). 1912 Fair Isle No localities, five, shot, between 24th September and 1st October.

(M. Bedford & W. E. Clarke, Scottish Naturalist 33: 5, 26, 28; Eds., British Birds 6: 351; W. R. Ogilvie-Grant, Bulletin of the British Ornithologists' Club 34: 271; Witherby, 1920-24; Bedford, 1937; Thom, 1986; Dymond, 1991).

History Mary, Duchess of Bedford & Wm. Eagle Clarke (1913) in the Scottish Naturalist, Vol. XXXIII. pp. 5, 26-28, say: 'The following notes are based upon the daily records of our bird-watcher, Mr. Wilson; on personal observations made during the latter half of September and in October; and on contributions by Mr. George Stout, who spent an autumn holiday on his native island....on the 24th, Blyth's Reed Warbler....on the 30th [September], a Blyth's Reed Warbler....on the 1st [October], another Blyth's Reed Warbler.'

Further, p. 28, they add: 'The finding of four, perhaps five, examples of this extremely rare British bird was the premier ornithological event in Scottish ornithology for the year. No doubt more examples were present, for all those which came under notice were found in cover, where they were only discovered by diligent and systematic searching of the patches of potatoes and the long course grass. They all occurred during our visit to the island, and all but one came under our personal notice. They are plain little birds and might easily be overlooked, and were, moreover, skulking in their habits. The dates of their occurrence were 24th, 26th, 29th, and 30th September, and 1st October. It was first recorded as British from a Fair Isle specimen obtained in the autumn of 1910.'

In an Editorial (1913) in British Birds, Vol. VI. p. 351, they say: 'In recent numbers of the Scottish Naturalist interesting articles have appeared on migrants observed in 1912 by The Duchess of Bedford and Mr. Eagle Clarke, in Fair Isle, and by the Misses Rintoul and Baxter in the Isle of May. The rarer occurrences recorded are mentioned below...At Fair Isle four or five occurred on September 24th, 26th, 29th and 30th, and October 1st (p. 28). This is very interesting especially in view of the fact that one has already been recorded in our pages at Holy Island, September 25th and another in Holderness, Yorkshire, on September 20th (supra, pp. 206 and 217). Yet previous to the autumn of 1912 the bird was only known to have occurred once in the British Isles, viz. at Fair Isle on September 29th, 1910.'

Mary, Duchess of Bedford (1937: 37) says: 'September 22nd, 1912. Arrived Fair Isle at noon....September 23rd, 1912. one Blyth's Reed Warbler.'

Comment It would appear from the above that the sightings on the 26th and 29th were not seen by Eagle Clarke.

8). 1912 Northumberland Holy Island, shot, 25th September.

(H. F. Witherby, British Birds 6: 206-208; W. R. Ogilvie-Grant, Bulletin of the British Ornithologists' Club 34: 271; Witherby, 1920-24; Galloway & Meek, 1978-83).

History H. F. Witherby (1912) in British Birds, Vol. VI. pp. 206-208, says: 'On September 25th as we were beating out the last hedge before turning homeward just after four in the afternoon, a brownish Warbler flew across from one hedge to another, and on alighting made a double note which may be syllabled "tup, tup", sounding something like the alarm note of a Lesser Whitethroat, but much softer and less harsh.

We then beat the hedge gently, but the bird kept well in the middle, and neither Miss Jackson nor I could get more than a momentary view of it. I then shot it, and on picking it up thought on account of the want of any reddish tinge in its plumage that it might be a Marsh Warbler. Its wing-formula was, however, wrong for this species, and subsequent examination and comparison have shown it to be a very difficult specimen to identify with certainty.

On dissection it proved to be a female, and a bird of the year freshly moulted into first winter-plumage. It was exceedingly fat. In coloration it exactly matches specimens of A. dumetorum, the upperparts being dark brown without any of the reddish tinge which is always present in A. streperus. The flanks, as in A. dumetorum, are scarcely marked with buff, while in A. streperus (especially in young birds in autumn) the flanks are strongly washed with buff. The wing-formula is, however, not quite typical of either species. The second primary is equal to the fifth, and the third and fourth primaries are emarginated on their outer webs. In A. dumetorum the second primary is almost invariably shorter than the fifth, and is very often shorter than the sixth. But I have examined one or two specimens in which the second is equal to the fifth, and several in which it is only a shade shorter than the fifth. In A. streperus the second is generally equal to or a little shorter than the fourth, and very rarely so short as the fifth. The wing measures 60 mm., which is right for A. dumetorum, but rather small for a female A. streperus.

Taking all the characters together, I must therefore conclude that this is a specimen of Blyth's Reed-Warbler (Acrocephalus dumetorum), although it is unfortunate that it is not quite typical. The note of the bird, which I have described above, was unlike any note that I have heard a Reed Warbler utter. The wind on this date was blowing fairly strongly from the S.S.E., and had been S.E. for several days previously. Blyth's Reed Warbler has only been once recorded before for the British Isles, viz. one obtained at Fair Isle by the Duchess of Bedford on September 30th, 1910.* But the bird is so nearly allied to the Reed and Marsh Warblers that it might very easily escape detection.'

[* The interesting announcement of the occurrence of another example (in Yorkshire) a few days before the Holy Island specimen, is made by Mr. J. K. Stanford a few pages further on. - H.F.W.]

Comment Miss Jackson is probably Annie Jackson who became the wife of Richard Meinhertzhagen.

9). 1912 At sea Sea area Humber, Dudgeon light-vessel, 19 miles off Wells, Norfolk, found dead, 20th to 21st October.

(W. R. Ogilvie-Grant, Bulletin of the British Ornithologists' Club 34: 271; H. F. Witherby, British Birds 8: 274; Witherby, 1920-24; Seago, 1977; M. J. Seago, Norfolk Bird & Mammal Report 1992: 498).

History W. R. Ogilvie-Grant, Editor (1914) in the Bulletin of the British Ornithologists' Club, Vol. XXXIV. p. 271, on the unexpected occurrences for 1912, says: 'One Dudgeon Lt-v. (Norfolk), October 20th/21st.'

H. F. Witherby (1915) in British Birds, vol. 8, p. 274, in a Review of 'Report on the Immigration of Summer-residents in the Spring of 1913; also Notes on the Migratory Movements and Records received from Lighthouses and Light-vessels during the Autumn of 1912', by the Committee appointed by the British Ornithologists' Club, says: "Among the uncommon visitors recorded most have been mentioned in our pages, but the following deserve notice: - Blyth's Reed Warbler (A. dumetorum), one at the Dudgeon Lightvessel (Norfolk) on the night of October 20th-21st, 1912, is an interesting addition to those already recorded in the same autumn (cf. Vol. VI.)".'

M. J. Seago (1992) in the Norfolk Bird & Mammal Report, p. 498, does not accept this record for Norfolk any more, because it is too far out at sea.

10). 1928 Fair Isle No locality, male, shot, 24th September.

(J. H. Stenhouse, Scottish Naturalist 49: 9; Eds., British Birds 23: 70; Thom, 1986; Dymond, 1991).

History J. H. Stenhouse (1929) in the Scottish Naturalist, Vol. XLIX. p. 9, says: 'On the 24th [September] a male Blyth's Reed Warbler (Acrocephalus dumetorum) was shot among standing corn, the first record of this bird since 1912.'

In an Editorial (1929) in British Birds, Vol. XXIII. p. 69, they say 'Surgeon Rear-Admiral J. H. Stenhouse records (Scot. Nat., 1929, p. 9) the following as occurring at Fair Isle in the autumn of 1928: - Blyth's Reed Warbler (Acrocephalus dumetorum). - One on September 24th.'

AC pass

Keith Naylor

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Acrocephalus dumetorum Blyth, 1849 (10, 0)

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