Pallas's Leaf Warbler
Phylloscopus proregulus (Pallas, 1811) (1, 2)
Photo © Kris Webb
Ex BBRC species 31/12/1990
STATUS
Palearctic. Monotypic.
OVERVIEW
Records as per BOU (1971). This species arrives here slightly later than Yellow-browed Warbler, mainly from mid-October onwards through to late November.
Overwintering has occurred since (February 2019).
RECORD
1). 1896 Norfolk Cley-next-the-Sea, adult female, shot, 31st October, now at Birmingham Museums and Art Gallery (Acc. No. 1954Z1.1017).
(T. Southwell, Zoologist 1896: 466-467; H. E. Dresser, Zoologist 1897: 5-7; T. Southwell, Zoologist 1897: 8-12; G. Wilkinson, Field 30th Jan., 1897: 135; H. E. Dresser, Transactions of the Norfolk & Norwich Naturalists' Society 6: 280-290; J. H. Gurney, jun., Zoologist 1897: 135-137; Eds., Ibis 1897: 143; Pashley, 1925; C. Borrer, Shooting Times & Country Magazine, 16th Sept., 1955; C. Borrer, Birding World 13 (3): 126-127; Stoddart & Joyner, 2005; Watson, 2010).
History Thomas Southwell of Norwich (1896) in The Zoologist, 3rd series, Vol. XX. pp. 466-467, says: 'In the November number of The Zoologist, Mr. Caton Haigh recorded the occurrence of Phylloscopus viridanus on the Lincolnshire coast, and I have now the pleasure of adding yet another rarity, killed this time on the adjoining coast of Norfolk, to the already remarkable list of continental wanderers which have been recorded for this section of the east coast. The past autumn has been exceptionally productive of these "East and West" immigrants, and already the Great Spotted Cuckoo, Aquatic Warbler, and Black-breasted Dipper had been met with (all of which will doubtless be duly recorded by Mr. Gurney in his usual Norfolk notes), when Mr. Pashley, of Cley-next-the-Sea, sent me for determination a pretty little warbler which Mr. Gurney recognized as Phylloscopus proregulus, a finding which Mr. Dresser was subsequently kind enough to confirm; the latter gentleman also exhibited the little stranger at the meeting of the Zoological Society on December 1st.
The bird, which was killed at Cley on October 31st last, is in perfect condition, and, I imagine, adult plumage. P. proregulus may readily be distinguished from P. superciliosus, which it somewhat resembles (which latter species has already been killed in Norfolk), by the pale mesial line on the crown, also by the conspicuous pale yellow of the rump....One can hardly conceive of this and other equally delicate Warblers straying such an immense distance from their native haunts, and how they can survive such a journey across the whole of Europe, finishing with the North Sea.'
H. E. Dresser (1897) in The Zoologist, 4th series, Vol. I. pp. 5-7, says: 'Quite recently a specimen of Pallas's Willow Warbler, Phylloscopus proregulus (Pall.), was forwarded to me for examination by Mr. Thomas Southwell, of Norwich, and I exhibited it on his behalf at the meeting of the Zoological Society held on Tuesday, Dec. 1st. This bird, which was obtained at Cley-next-the-Sea, Norfolk, on Oct. 31st last, affords another instance of the fact that most of our recent additions to our British avifauna are visitants from the East, chiefly from Northern Asia....To return, however, to Pallas's Willow Warbler.
This interesting little bird was first described in 1811 by Pallas (Zoogr. Ross. As. I. p. 499), but Gould figured and redescribed it in 1837 (B. of Europe, II. pl.149), and gave it the name of Dalmatian Regulus, Regulus modestus....The British-killed specimen was shot by a son-in-law of Mr. H. N. Pashley, who has obtained so many rarities at Cley-next-the-Sea, where the last one procured was the Aquatic Warbler.'
Thomas Southwell (1897) in The Zoologist, 4th series, Vol. I. pp. 8-12, says: '... In my previous notice of the occurrence of this bird, in the December number of the Zoologist, p. 467, I remarked that this species may be distinguished from P. superciliosus by "the pale mesial line on the crown". I should have stated that this "mesial line" in P. superciliosus is much paler than in P. proregulus, and that in females and young birds, according to Mr. Gätke, there is not even a trace of it. The most conspicuous difference, however, is the pale yellow colour of the rump in the latter species.'
J. H. Gurney, jun. (1897) in The Zoologist, 4th series, Vol. I. pp. 135-137, says: 'October 31st. N.E. Mr. E. Ramm shot a very small bird, as recorded by Mr. Southwell (Zool., p. 8), which, from the exact description in Gätke's Birds of Heligoland, pp. 294, 295, was soon identified as Pallas's Willow Warbler, Phylloscopus proregulus, Pall. For other synonyms see Catalogue of Birds in B. M., V. p. 71.
The Norfolk Pallas's Warbler is a little smaller than the Yellow-browed Warbler, P. superciliosus. Its upper parts are a rather purer olive-green, and the yellow markings of the head and neck are considerably richer, especially the eye-streaks, and a rather broad stripe extending across the crown of the head to the nape of the neck. The bands on the wings are a little broader, but they only reach half-way to the outer edge of the wing, and across the rump there is a band of lemon-yellow. Mr. Pashley jotted down the soft parts while they were fresh as follows: - Upper mandible dark brown, lower orange nearly to the tip; legs brown, feet yellowish. Length, 3¾ in. barely. Sex female. Through Mr. Dresser's kindness I am able to give representation, the size of life, from a drawing prepared for the Birds of Europe, Supp.'
George Wilkinson of Holt (1897) in The Field of 30th Jan., Vol. LXXXIX. p. 135, says: 'As I have not seen mention in your paper of a recent addition to the list of British birds, I venture to send you the following particulars, thinking it will be of interest: In the latter part of last October a strange little bird was shot at Cley-next-the-Sea by Mr. Edward Ranna [sic]. It was forwarded to Mr. T. Southwell, of Norwich, who identified it as Pallas's Willow Warbler (Phylloscopus proregulus). This opinion was confirmed by Mr. Dresser, the author of The Birds of Europe, who states that it is the first specimen taken in the British Isles, the nearest one to England having been taken at Heligoland. I have extracted these particulars from the Norfolk Chronicle of the 16th inst.' [The circumstance was recorded by Mr. Southwell in the Zoologist for December last, and in the current number of that journal he has supplied a fuller account of it. - Ed.]
H. E. Dresser (1897) in the Transactions of the Norfolk & Norwich Naturalists' Society, Vol. VI. pp. 280-281, says: 'One of the most interesting additions that has been made to the avifauna of the British Islands is certainly that of Pallas's Willow Warbler (Phylloscopus proregulus), a single example of which was shot at Cley-next-the-Sea, Norfolk, on the 31st October, 1896, by Mr. Ramm who forwarded it to Mr. Thomas Southwell, and informed the gentleman that he "found it amongst the long grass on the bank or sea-wall, not far from the sea at Cley, a locality which has produced many rare migrants, and at first took it for a Goldcrest, but on approaching to within two or three yards, the bird being very tame, he thought he recognised a Yellow-browed Warbler, a species he had seen before, and therefore secured it".
Mr. Southwell identified it correctly as Pallas's Willow Warbler, but forwarded it to me for confirmation, and at his request I exhibited it at a meeting of the Zoological Society on the 1st December last. On comparing the bird with those in my collection from Siberia and the Himalayas it agrees most closely with a fully adult bird from Siberia; and I may here state that it is an adult female in very fresh plumage and is quite as bright in tinge of colour as any Siberian specimen I have seen.'
In an Editorial (1897) in The Ibis, Vol. XXXIX. p. 143, it says: 'At the Meeting of the Zoological Society of London on December 1st, 1896, Mr. H. E. Dresser exhibited and made remarks on a specimen of Pallas's Willow-Warbler (Phylloscopus proregulus), shot at Cley-next-the-Sea, Norfolk, on the 31st October, 1896, being the first instance of the occurrence of this bird in Great Britain.'
Pashley (1925) says: '1896. October 31st. Pallas's Willow Warbler, first occurrence in the British Isles.' Further, under 'List of Cley Birds', he adds: 'Shot by Mr. E. Ramm and now in the Connop collection.'
Comment Preserved by H. N. Pashley of Cley, Norfolk. The Connop collection was housed in Rollesby Hall until 1912 when it was purchased by W. R. Lysaght of Chepstow; his collection passed to the City of Birmingham Museum.
1950-57 RECORDS
2). 1951 Northumberland Monks' House, Seahouses, adult male, trapped, 13th to 15th October.
(E. A. R. Ennion, British Birds 45: 258-259; G. W. Temperley, Naturalist 77: 116).
History E. A. R. Ennion (1952) in British Birds, Vol. XLV. pp. 258-259, says: 'On October 13th a willow-covered burn was being driven towards the garden Heligoland trap here; when what appeared to be one of several newly-arrived Goldcrests (Regulus regulus) flew into the trap. Goldcrests normally take no notice of the driving. I then saw that it was not a Goldcrest and, on going round to the gathering-box, found what I took to be a Yellow-browed Warbler (Phylloscopus inornatus).
But, on handling, the prominent central crown-streak; the brilliant yellow superciliary stripes meeting at the nape; the sharply defined lemon-buff bar, a quarter of an inch wide, across the rump; and the minute size decided in favour of Pallas's Warbler (Phylloscopus proregulus), presumably an adult male from the brilliance of its colouring.
Although none of us had seen before either Pallas's or Yellow-browed Warblers, the seven of us who examined the bird in the hand (and later at large at "goldcrest range" in low thinly-foliaged willows) were satisfied that it could only be Ph. proregulus according to the descriptions given in The Handbook.
We noted when the bird was in the hand that the third, fourth, fifth and sixth (slightly) primaries were emarginated; fourth and fifth equal in length and third considerably shorter. It was ringed (MD 616) and released and went straight back to the willows, where it remained collecting aphids with the Goldcrests for the rest of the day. It spent the morning of the following day, October 14th, in the willows and, at midday, flew across into a large sycamore tree: the flight was exactly like a Goldcrest's. It remained in this tree until evening, flitting about and frequently hovering to pick aphids off leaves, but remaining persistently beneath the canopy of the crown of the tree. It was never seen to work out to the exterior of the tree, nor to hover below terminal leaf-clusters, as a Chiffchaff (Phylloscopus collybita) or a Willow Warbler (Ph. trochilus) would have done; and yet, in the willows, it had taken very little more notice of our presence than did the Goldcrests.
In the evening it returned to the willows and also, for the first time, visited an adjacent row of stunted firs; when, at last, several members of the Ornithological Section of the Northumberland, Durham and Newcastle-upon-Tyne N.H.S. had clear views of the bird at close range. They agreed with our findings and diagnosis of the previous day. It was active until dusk, for an hour after the Goldcrests had retired to roost, and disappeared on the following day, October 15th.
It was, if anything, even smaller than a Goldcrest, which it resembled fairly closely in habits but not in appearance. It was more prone to hover; apt to flit farther between bouts of searching; and seldom hung upside down. The wings were flicked incessantly in a Dunnock-like way. The silhouette was not so rounded; the general coloration darker above and paler below; much brighter in hue; and the impression of pattern much more pronounced; the folded wing-tips were longer in proportion to the tail and the legs shorter and darker; the eye was smaller and the "face longer" than in the Goldcrest.
This would seem to be its second occurrence in Britain, the first bird having been "obtained" at Cley (Norfolk) on October 31st, 1896. On the present occasion a heavy passage of Robins, Blackbirds, Song-Thrushes, Redwings, Bramblings and Goldcrests had been in progress for several days, in spite of predominant south winds only occasionally veering east.'
[Dr. Ennion's account published above was accompanied by some excellent coloured sketches made on the spot, which help to confirm the identification. Mr. H. G. Alexander, who has very wide experience of the Phylloscopi in the field, is satisfied that the bird must have been proregulus. It is clear that proregulus is the only member of the genus on the British list which fits Dr. Ennion's description, but it has occurred only once before and the probability of its occurrence a second time is not much greater than that of other species not yet identified in Britain. The combination of the distinctive head-markings and a yellow band on the rump, and the absence of white outer tail-feathers are diagnostic. - Eds.]
G. W. Temperley (1952) in the new series of The Naturalist, Vol. LXXVII. p. 116, under 'Ornithological Report for Northumberland and Durham for 1951,' says: 'On October 13th an adult cock of this species was trapped and ringed at the Observatory, Monks' House, Seahouses. It was in the company of a number of newly arrived Goldcrests. Thanks to the kindness of Dr. E. A. R. Ennion, this bird was seen by several local ornithologists, as it remained in the garden for some 24 hours after being released. This is the first record for this species in the county of Northumberland and only the second for the British Isles.'
3). 1957 Norfolk Gore Point, Holme, trapped, 17th November, photo.
(Cambridge Bird Club, British Birds 51: 197, plate 36; Seago, 1977).
History Cambridge Bird Club (1958) in British Birds, Vol. LI. p. 197, say: 'On a field expedition of the Cambridge Bird Club on 17th November 1957, a small Passerine was flushed from an elder bush in the dunes at Gore Point, near Holme, Norfolk, by J. S. Clark.
The bird resembled a Goldcrest (Regulus regulus), but was seen to have a yellow rump. It flew into a patch of sea buckthorn, where J.S.C. drew the attention of others to it. The bird was then watched for half-an-hour by J.S.C, G. M. S. Easy, D. Farren, R. Genochio and C. H. Hagger, at a range of about five yards, and the following field-characters were particularly noted: (1) very small size, about that of Goldcrest; (2) primrose yellow rump; (3) pale yellow crown stripe; (4) yellow superciliary stripe above a very dark stripe running through the eye; and (5) two pale wing-bars. The bird was extremely active and spent most of its time low in the bushes, searching for insects. It sometimes hovered while feeding, like a Goldcrest, and the yellow rump was then very conspicuous. Occasionally it would make a short vertical flight from the bushes to snap up an insect, rather like a flycatcher (Muscicapa sp.).
It seemed clear that it was a Pallas's Warbler (Phylloscopus proregulus). The bird was then caught in a mist net, and ringed by P. R. Evans. Whilst in the hand it was photographed by J. L. Cutbill (see plate 36), and the following description and measurements were taken: Head: crown dark olive-green, with central stripe of pale yellow; prominent pale yellow superciliary, and very dark stripe through eye; cheek and throat pale yellow, merging to greyish-white under-parts. Mantle: bright olive-green. Rump: bright primrose yellow, very conspicuous. Tail: dark olive-green, square-ended; under tail-coverts pale yellow. Wings: olive-green with two pale yellow wing-bars; the anterior bar (formed by the tips of the median coverts) was narrower and less conspicuous than the posterior one (formed by the tips of the greater coverts); the edges of both primaries and secondaries were tinged yellow. Bill: rather heavy for the size of the bird; brown, with lower mandible paler at the base. Legs: dark sepia brown. Measurements: wing 50 mm., bill (from skull) 10.5 mm., tail 40 mm.
The bird was seen by about 30 members of the Club between 3.15 and 4 p.m., just before the party left to return to Cambridge. This is the second record for Norfolk and the third for the British Isles.'
NOT PROVEN
0). 1943 Norfolk Waxham, seen, 12th September.
(J. Vincent, Wild Bird Protection in Norfolk 1943: 12).
[BOU, 1971; Taylor, Seago, Allard & Dorling, 1999].
History Jim Vincent (1943) in Wild Bird Protection in Norfolk, p. 12, under 'Notes from Hickling', says: 'On September 12th, a hazy day with easterly wind, during a walk along the recently-made Waxham Cut Wall in company with another Hickling man, I saw the biggest hold-up of insectivorous birds I have ever seen in this district. It reminded me of a good day at Cley years ago. Common Redstarts were everywhere and among them was one Black Redstart.
Twice I flushed a small warbler from the sparse undergrowth, which at first sight appeared to resemble a Yellow-browed Warbler, but was more strikingly marked. The third time the bird was flushed it flew to a clump of tall seedy grass and fluttered with open wings showing a very pronounced yellowish rump. I know the Yellow-browed Warbler, and after seeing the hovering flight of this bird I knew was a stranger to me. It tallied in every respect with Pallas's Warbler.'
Taylor, Seago, Allard & Dorling (1999) state their first and second records as occurring in 1896 and 1957.
