Bermuda Phylloscopus — ID help needed!

Bermuda is one of the planet’s best vagrant traps, a completely isolated North Atlantic island about 1045 kilometers ESE of Cape Hatteras, North Carolina. The island’s relatively small size (53 square kilometers) and the absence of other nearby islands surely adds to its power as a vagrant trap. A good system of roads and limited fresh water make the best spots fairly straightforward to check, and a year-round cadre of keen birders are consistently turning up new surprises. That said, few North Americans visit specifically to seek vagrants, largely because it is not included in the ABA Area, which for many in the U.S. and Canada is still the most important listing region. With 361+ species and counting, it certainly deserves more coverage…

The Phylloscopus in the below photos was found by Wendy Frith and David Wingate in the Port Royal/Pompano dump area of Bermuda on 18 February 2014. Andrew Dobson returned the following morning and got these photos. To our knowledge, the calls have not yet been heard or audio recorded. Opinions on the identification have been divided thus far, so we invite Frontiers readers to help nail this one down.

Bermuda Phyllosc-DSC_9675 Bermuda Phyllosc-DSC_9696 Bermuda Phyllosc-DSC_9697 Bermuda Phyllosc-DSC_9691 Bermuda Phyllosc-DSC_9707


Phylloscopus in North America

Within North America, Arctic Warbler (Phylloscopus borealis kennicotti) breeds in mainland Alaska, and is a common migrant on some Bering Sea islands, such as St. Lawrence Island. All other species are vagrants. Alaska has vagrant records (almost entirely in fall) of Pallas’s Warbler (1), Yellow-browed Warbler (8+), Willow Warbler (11+), ‘Siberian’ Chiffchaff (2-3 records), Wood Warbler (3), Dusky Warbler (20+)–almost all from the western Aleutians, St. Lawrence Island (Gambell), or St. Paul Island (one of the Pribilof Islands). and Arctic Warbler, which breeds. The status of Kamchatka Leaf-Warbler (Phyllscopus examinandus)–not yet split by the American Ornithologists’ Union but clearly deserving of a split since Alstrom et al. (2011)–is not well known but is summarized to the best of current understanding by Howell, Lewington, and Russell (2014). It is at least a rare to casual spring migrant and very rare fall vagrant on the western Aleutians.

Away from Alaska, California has 7 fall records of Arctic Warbler (although some or all of those may refer to Kamchatka Leaf-Warbler) and an impressive 13 Dusky Warbler records, all from fall. Mexico actually has more Phylloscopus species than California, with two records of Dusky Warbler, one of Arctic (or Kamchatka Leaf-Warbler), and one record of Yellow-browed Warbler, all from the Baja California Peninsula. Otherwise, there is but a single sight record of Yellow-browed Warbler from the mid-continent, in Wisconsin. Greenland, a waypoint between Iceland and North America, has one record of Willow Warbler, from Hold With Hope, Myggbukta, 18 Sep 1937 (Boertmann 1994).

Obviously, a record of any Phylloscopus from Bermuda is a highly significant record and a first record for the island. Although a variety of Palearctic shorebirds, herons, waterfowl, and even raptors have appeared here, Palearctic passerine records have been very few. One of the more remarkable was a Dark-sided Flycatcher (Muscicapa sibirica) collected 28 September 1980
(Wingate 1983).

Please comment on the ID

With all that in mind, opinions on the identification of this Phylloscopus would be most welcome. Opinions thus far have been divided, so we could use some help from Palearctic birders who have a much better handle on this genus. The Frontiers audience is certainly better suited to comment than almost any other community in the world, so please give us your thoughts, along with supportive field marks that you see in these photos.


This entry was posted in 18) Warblers, Crests, Wrens on by .

About Team eBird, Cornell Lab of Ornithology

The six of us work at the Cornell Lab of Ornithology. Chris Wood, Marshall Iliff and Brian Sullivan coordinate eBird -- the global bird-recording scheme that has gathered 170 million records from over 150,000 users from every country in the world. Andrew Farnsworth coordinates BirdCast, a cross-disciplinary collaboration with computer scientists to predict regional and continental bird migration. Jessie Barry coordinates Merlin Bird ID, an app that uses crowdsourced data to help people identify common birds, currently focused in North America.. Tim Lenz is our eBird Programmer. In our free time, we are all Bird Race addicts and together we hold several Big Day records -- including the North American record of 294.

30 thoughts on “Bermuda Phylloscopus — ID help needed!

  1. Christian Cederroth

    Hi, being a Swede replying from Tapichalacha, Ecuador to Ingela Persson on Bermuda via this site I do enjoy the benefits of the net!

    At home (Segerstads fyr, Öland, Sweden) I would have passed by this as another Willow Warbler (Sweden’s most common bird), perhaps having touching Chiffchaff or Greenish Warbler in my mind due to its rather dark legs and — do I see a trace of a wing band on the greater coverts? Perhaps not, just bleached edges (and it’s enhanced by the malposition of the secondaries). Legs that dark are ok for Willow too. Primary projection not as short as on the more round headed Chiffchaff either it seems.

    The yellow traces on the underparts strongly point towards Willow even if the green leaves add to it.
    Dark underside of bill bad for Greenish, as is the lack of a pointed crown, better wingbands and even stronger eyebrow etc. Arctic is a way bigger bird and has of course the distinct dark bill tip, different facial pattern, eyebrow, primary projection etc.
    Ph. examinandus might match though, but I have no own experience of that. I believe it would resemble an Arctic though, for instance in size. So I would vote for Willow, anyone proving me wrong are welcome to debate of course, we bird and learn!

  2. Jane Turner (@Turnershbo)

    It appears to be a short-winged bird with a strong face pattern.If the supers were more strongly bridging I’d been leaning really quite heavily towards Greenish Warbler, despite the apparent lack of wing bar. As is it,diagnosis is still my lead option (heavily worn). I need to see it on a proper screen though

  3. Bryon Wright

    Relatively short and stubby looking beak along with the many other factors, most described above by Christian, make it a Willow Warbler, even with Ph. examinandus comparison.

  4. Jane Turner (@Turnershbo)

    Now I can see it on a monitor, I have more questions than answers

    1. How many tertials can we see? None is possible! The secondaries are all over the place in most photos – and appear to be “uncovered”

    2. Could the apparent colouration on the underparts down to wear – the bases of phyllosc contour feathers are greyer than the tips (from memory – its 18 years since I handled one)

    3. Is that a clean pale tip to at least one fresh greater covert on the left wing… however if they are fresh feathers, the tips look rather small on the sideways on photo in terms of their ability to produce a wing bar when all present

    4. Is the short primary projection down to moult – leaving aside the state of the tertials, the distance between the longest secondary and the tip of the wing seems very small (Greenish/Chiffchaff-like)

    5. Its the apparent short tail down to moult too.

    I’d ask for help from someone from central Asia, who is used to seeing Phylloscs at their worst plumage-wise. I still lean towards one of the Greenish complex… but am a long way from sure

  5. Harry Hussey

    I’m oddly torn between Willow Warbler and something from the Greenish complex here. While the primary projection appears on the short side in some images, it is perhaps best evaluated from the third image, being in profile, and seems a bit longer here. Also, perhaps the hints of yellow below would point more strongly towards Willow, the leg colour could perhaps fit Willow (not all are pale-legged, of course) but fits Greenish too. I don’t see Chiffchaff having a head pattern this pronounced, it just doesn’t suggest that species to me (plus Chiffchaff is the only member of the genus that I regularly see, albeit in small numbers, at this time of year, and they don’t tend to be this tatty/obviously in moult, either). This could all be solved easily with some sound recordings, or descriptions of the call…

  6. Phil Woollen

    Super doesn’t reach base of bill ruling out Greenish? Super extends long way behind eye – good for Arctic. Can’t really determine primary projection but gives impression of long winged. I’d go for Arctic

    1. Jane Turner (@Turnershbo)

      Plenty of scruffy Greenish Warblers in Jan-Apr on the OBC site sans bridges Phil. I’ve listed a few above here – its just not been moderated yet. The bill is too short, the wings too short and the legs too dark for Arctic surely. I can forgive a WW having dark legs, but Arctics usually have very striking pale legs

  7. linosabirding

    The GC (greater coverts) even if very ruined as the whole plumage (that’s why tertials seems to be missing, as covered by desplaced secondaries!) clearly show a pale spot not shown by Willow not even in fresh juv plumage in autumn…. also, jizz, PP (primary projection) etc rule out to me Willow W. The plumage, as reported, is really too bad to give as a clear clue but from what I see I could try to make that Phyllos into a Two-barred Greenish (plumbeitarsus!!)…. the MC are very abraded and weared off so the second wing bar is not visible, well, actually the entire MC are not visible here (they even seems to be missing altogether or strongly abraded !)…. BUT bill structure, wing PP, tail -tip : wing-tip ratio, supericlium above lores pattern, legs colour and structure etc point towards plumbeitarsus …or at least towards one of the Greenish W complex taxa !! that my opinion IMO !!

    a great observation in any case

    1. Jane Turner (@Turnershbo)

      The good news is that its been there since last autumn and it should grow some useful feathers back. Not sure that I can find anything structural to help with Two-barred greenish,but Greens have different shaped bills that I can detect in a small sample.

  8. Sean McCann

    Apologies if this dupes up. Not sure if the original got lost in the ether or is being monitored for industrialisms before being allowed to be shown to the world.

    Can’t be bothered to rewrite the orig, but from photo 3 I would have gone for Greenish, as it doesn’t look particularly long and sleak in either wing or tail, but does defo look to have a covert bar. This must rule out Willow.

    However, in photo 5 the bird looks longer and sleaker, with a gentle long arc to the crown, underparts that (in different light) now look sullied light grey rather than slightly tinged yellow, grizzled ear coverts (also in photo 3), possible dusky smudge to distal lower mandible, all of which look good for Arctic, plus Phil W has already commented on the lores and super ‘pattern’ being suggestive/diagnostic of Arctic.

    The way the greyish flanks abruptly turn off white just before reaching the tertial tips (see photo 5) exactly matches the plate in Svensson (1999), that publication (along with some photos out there on the net) largely being the basis for my comments – credit where it’s due and all that.

    This is like the ID parade in Never Mind the Buzzcocks. Is it bird 3 or bird 5? Would the real Bermuda Phyllosc please step forward…

  9. Sean McCann

    “Using photographic morphometics”

    Which is likely to produce a result about as accurate as constructing a microchip while wearing heavy duty gardening gloves.

    I haven’t seen that particular brand of dark arts wielded since the Great Alder Flycatcher Swindle. Yes in all likelihood was one but the ‘scientific case’ that ‘proved’ it was one (based on a photograph) was so flawed it was laughable and anyone that thought it held any water should be permanently barred from sitting on the BBRC.

    This bird may be a Greenish, it may be an Arctic, it may be something else, but an unequivocal ID is only going to come out of Bermuda.

  10. Bryon Wright

    Would advise any interested party to look at the Dig Deep’, Malaysia, site on the web by Dave Bakewell. DB. looks at the new ‘Arctic complex’, with a practical, fresh eye, as well as with humour and originality. Who ever would have thought that the ‘Arctics’, would be extensively split and the ‘Greenish’, more or less retained intact, thirty years ago, Kenneth Williamson perhaps?

    Back to this bird, it not often these type of photos give us an even break. The bird does have a strong but still diffused supercilium and I still go for one of the ‘eastern’, type Willow Warblers, birds like this turned up in the middle east. Someone has already pointed out that in the Greenish super, does not stop but continues to join above the bill. The rear view of the crown in this bird, Arctics of all types invariably have a long thin and well defined, super. encroaching right to the rear of the crown and often ending in an flamboyant terminal flourish. The pale edgings and patterning to the under-tail tips is interesting.
    The perceived colour which I did not originally, mention, seems totally right for Willow as Christian and others suggest.

  11. Sean McCann

    Right, I’m guessing my first post was probably auto-mod’d due to not liking an innocent use of the male version of the word ‘hen’.

    So here we go again…

    My first gut response was Greenish, due to the slightly ‘stumpy’ look to the bird, and mostly down to the strongish white tips to some of the coverts, creating a sort of bar which should rule out Willow straight away. This was based on photo 3.

    However, when looking at photo 5, the bird looks to have a longer/sleaker profile, and several features point heavily toward Arctic: 1) the hint at a dark smudge on the distal underside of the bill; 2) the lores/supercilium pattern as already noted by Phil W above; and 3) the underparts now look sullen light grey rather than yellow tinged, and the way the flank greying abruptly turns off-white just before the level of the tertial tips is an exact replica of the Arctic Warbler plate in Svensson (1999).

    The problem with using photos off the internet as a basis for judgement is that many of them are probably mislabelled. Given there are at least three different opinions on what the Bermuda bird is, why should we place much confidence in labelling of the zillions of other photos out there? One of the first ‘Greenish’ photos I looked at, taken in SE Asia, was an Eastern Crowned or something of that nature – slaty crown with a pale central coronal stripe, so not a chance of it being Greenish.

  12. julianhough

    The only comment I can make at this point, is that the bird is not an Arctic Warbler – if this bird was seen in the UK, it wouldn’t pass muster as one…head pattern, skinny legs leg color, etc.

  13. Bryon Wright

    The Jon Hornbuckle , ‘ Arctic ‘, photos, above of the coverts emerging from pins, always wanted to see this! Without wishing to obfuscate, but the point is that due to the splits some of these published photographs are probably not actually ‘Arctic’ any more, the Asian photos are just as likely to be of Japanese Warbler or one of the other splits!!! This is does not even take in to account Sean’s point as well about the probably many wrongly captioned, published photos.This is why I mentioned DB’s website Think the id. from moulting new feathers will also be indecisive as well. The perceived paler edgings, to the coverts in the Bermuda Photographs are in my view a photographic misperception and a trap, Arctic in winter has subtle ,usually narrow, white covert edgings when all of them are present , but I am willing to accept my reading of the photos could be wrong. Furthermore ‘Arctic’s’ and to lesser extent ‘Greenish’ usually continually call on their wintering grounds.

    1. Jane Turner (@Turnershbo)

      Agree, but they are “arctic complex” and we are still debating whether its a Willow Warbler, Arctic Complex or Greenish complex – so fretting abut which flavour of Arctic is is or isn’t is a bit in running before walking territory

    2. sean mccann

      “The perceived paler edgings, to the coverts in the Bermuda Photographs are in my view a photographic misperception and a trap”

      Mmm, the more I look at these photos the more I’m inclined to man up and agree with the above. Not seen Arctic in the hand before. I’ve looked through some photos of ‘Arctics’ and the covert feathers do seem to be more white on the outer webs, but the outer webs on the entire wing of the Bermuda bird are reflecting paler and the covert tips don’t look a degree even paler, so yeah this could be a strong sunlight trap and I’ve probably fallen into it.

      As for the greyish underparts in the shaded photos, I guess that’s easier to explain than the appearance of yellowish tinge to the underparts in strong light ie. easier for colour to be washed out than to be created out of nowhere. Be nice to see a photo of the bird in neutral light as it almost looks like 2 different birds depending on whether it is strongly or poorly lit.

      If the covert bar is a red herring, everything else looks sound for Willow really – colouration (incl. legs), super, PP, bill. Slightly short tailed feel in some photos possibly just posture/angle. As Christian said originally, (in the absence of a covert bar) you could probably pass it off for 1W Willow without giving it a second glance.

      1. Jane Turner

        “but the outer webs on the entire wing of the Bermuda bird are reflecting paler and the covert tips don’t look a degree even paler, so yeah this could be a strong sunlight trap and I’ve probably fallen into it.”

        The inner webs of Phyllosc remiges are strongly white edged-you just don’t get to see them unless the tertials are missing,or someone over spreads the wing.

  14. Per Larsen

    It is a willow warbler, no doubt and most likely 1st winter. The belly is less white, it is more yellowish and the bright cheeks are fringed with dark olive (most obvious on the 1st photo). Arctic and greenish have a wing bar, and sometimes two. Arctic is darker and has a stronger contrast. Greenish moult in the autumn, so the wing bar would still be present in February. Arctic moult in the autumn and even later. Willow warbler lives closer to Bermuda, than the other two species, so it will more likely appear on Bermuda.

  15. Dave Gandy

    On moult, the fascinating Williamson Guide (1976) notes that Arctic, Greenish, Two-barred Greenish and Willow Warbler all have a complete moult on the wintering grounds (Willow being unique amongst the Phylloscs as it is the only one to have two complete moults in a year). Interestingly it also states that by mid-Feb many Willow Warblers are finishing their moult, with a few late birds continuing into March. Whilst caution needs to be exercised on extrapolating this to a vagrant, it might be a factor that counts against this bird being a Willow Warbler.

    1. Jane Turner

      Its easy to find Greenish complex and Arctic complex birds in this exact state of moult at this time of the year (and so far I’ve failed to find Willow -but there are fewer photographers in S and SE Africa than S and SE Asia). Saleweski et al.J Ornithol. (2004) 145: 109-116 showed that WW usually moult in Dec,completing by Feb, but that timings vary more than in other species (possibly affected possibly by environmental factors)…. that said its generally the body feathers that can be delayed. This bird is in possession of ancient and excessively worn contour feathers.

  16. julianhough

    An intriguing bird, made difficult by the reflections from the leaves and the harsh lighting. While I still am not struck by this as Arctic, my reference to it having “skinny legs” was that to me, Arctics tend to look to have quite stout or thicker tarsii (like Radde’s), perhaps due to their often paler coloration.

    Hope that is more descriptive for you Mr. McCann in quantifying my statement which was no more unhelpful than your statement, “My first gut response was Greenish, due to the slightly ‘stumpy’ look to the bird”.

    Are you saying that one of the clinching features was that it looks like one of the seven dwarfs?

    I think I am ahead, got to get back to my Playboy now…


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