Possible Lesser Sand Plover in Virginia

[AndyB]

photos here (http://www.flickr.com/photos/wendeldh/3895424300/in/photostream/)

[Brian S]

Hi Andy

I feel sure that this is a Lesser Sand Plover (ie the atrifrons group) - as opposed to Mongolian Plover (ie the mongolus group). The bill structure looks good to separate it from Greater; the length of the exposed tibia looks shorter to my eyes on Lesser than Greater, but perhaps it is best not to dwell on this too much.

A good find. I would be interested to know how many records there have been on the east coast of the US; I suspect it may well be as many as the UK.

Brian S

[Red-eyed Video]

Agreed with Lesser Sandplover, not sure about the race though, I would have said adult non-breeding mongolus off the top of my head.

Which race was at Rimac? This one looks similar.

[W. Ruskin Butterfield]

More photos:
http://www.visitingnature.com/sandploverspecies.htm .
Locals are thinking Greater.
http://elibrary.unm.edu/sora/NAB/v055n03/p00252-p00257.pdf

[AndyB]

There have been just a handful of "Lessers" on the east coast.

More photos here:
http://birdimages.posterous.com/staunton-va-sand-plover-images
http://www.birdsofvirginia.com/GalleryPages/Sandplover_Galary.html
http://www.flickr.com/photos/28499865@N07/sets/72157622171078927/
http://shoch.smugmug.com/Other/Sand-Plover/9553040_iMPVy#642448310_5Qd9y


Erik Hirschfeld commented on the photos to one VA birder I'd like to see more photos, but everything on these photos with regards to stance and head/bill point to Greater. The bill is quite small, but on at least on one picture it looks more massive. ID Frontiers seems fairly split on the ID.

[Red-eyed Video]

Quite small to more massive is quite a significant step.

Looking at some of the photos in isolation it could stand as a Greater, has it been seen in flight?

[AndyB]

In-flight photos here (http://www.pbase.com/vatrekker/sandplover_in_virginia_2009). Tail appears fairly uniform(?) and bill shape would conform to my impression of Lesser (Dave Bakewell's always entertaining blog has a good example of a large-billed Lesser (http://digdeep1962.blogspot.com/2006/09/saturday-26th-august.html)). Also, don't Greaters moult before migrating south so one would not expect a Greater with hints of breeding plumage at this time of year?

I read Hirschfeld is pronouncing a Greater of the large-billed group and Pyle has also agreed with the ID
Yes, definitely. And on this link http://www.birdsofvirginia.com/ImageLinks/SandPloverA_Link.html it is quite clear that it is of the leschenaultii/crassirostris subspecies group. The bill cannot look like that on a columbinus (and certainly not on any mongolus subspecies) , e. g. the angle on the lower mandible is very prominent.

I obviously flunked Sandplover school!

It would be good to see some crisp photos though. Apparently, the bird is showing well but there just seems to be a lot of hazy digiscoped images to look through. Colin, now's the time for the DSLR boys to show us the money!

[Brian S]

Andy

It is interesting to see the various images, some of which appear to show the bill as having a slightly finer tip. However, in the majority the bill still seems to me to be shorter than I would expect for Greater.

Brian S

[CAU]

This photo clearly shows a classical Lesser Sandplover-like bill:
http://www.birdsofvirginia.com/ImageLinks/SandPlover_Link.html
The tip is blunt and the bulb covers clearly less than half of the length of the bill. Also e.g. the round head fits perfectly Lesser Sandplover.

[Colin Key]

Colin, now's the time for the DSLR boys to show us the money!

Hi Andy,

I have only a passing interest in this bird but have looked at all the photos (and some are taken with a Canon DSLR) which are appalling and on the basis of which, in my opinion, a firm I.D. could not be made. From the potential rarity status of this bird I am surprised that no-one with top end gear has tried to get some shots of this bird.

Pity that you are so far away - the Pentax and Kowa might well have got the "money shot" :cool:.

Best,

Colin

[JanJ]

Stranger things has happend. Just goes to show that - in this case - bill shape/size is sometimes very difficult to judge! In some images it looks rather thin-tipped, in others more blunt-tipped. However, in most images of the subject sandplover, mongolus group could be counted out due to bill size and shape. One of the atrifrons group fits most perfectly, since longer-billed and longer-legged. Structurally it looks better for Lesser. The reason why Erik has suggested Greater I can´t say for sure, perhaps the underwing view in some of the images shows no dark carpal and is overall white - darker in Lesser with a dark carpal bar.
However, I think that some individuals are more difficult than people are aware of, some eastern greater looks rather short-billed and short-legged, while in one of the images the subject bird looks rather long-legged (long tibia), which in that case would fit Greater better. It would be very nice to see some better, sharper images!

http://3.bp.blogspot.com/__Dq5_ABpFrs/SQayfR9tzuI/AAAAAAAAFMI/y5063O2DMZo/s400/Greater+and+Lesser+Sand+Plover_Lok+Kawi_241008_IMG _9780.jpg

http://homepage2.nifty.com/stints/ploveretc/greatersandplv.html

http://homepage2.nifty.com/stints/ploveretc/lessersandplv.html

JanJ

[Frostbyte]

This bird has catalyzed exceptional excitement and vexation for many of us in the Virginia region. Sand-Plover identification appears to be something of a dark art - it is a shame (though not surprising, given the location) that noone with extensive experience with both species has seen the Staunton bird in the field.

The bird has not been re-found as of ~12 pm local time today (9 Sept).

This photo clearly shows a classical Lesser Sandplover-like bill:
http://www.birdsofvirginia.com/ImageLinks/SandPlover_Link.html
The tip is blunt and the bulb covers clearly less than half of the length of the bill. Also e.g. the round head fits perfectly Lesser Sandplover.

This would seem a poor photo for evaluating these characters. The bill is held at an oblique angle relative to the observer, and most of the feathers are held erect, as during a bathing or preening bout. I had rather different impressions during my field visit.

I understand that the best photos are being assembled for review by a "blue ribbon panel" of Sand-Plover experts (some names mentioned earlier in this thread).

If this bird pertains to a subspecies of the atrifrons group, I believe it would represent the first N. Am. record.

[joemorlan]

There's a pretty nice photo up now on the "North American Stop Press" page. I think it shows the bill pretty well.

http://www.surfbirds.com/cgi-bin/gallery/display.cgi?gallery=gallery10

[AndyB]

Welcome to the forum Frostbyte and congrats on seeing a terrific state bird.

Thanks Joe, that's a good profile shot of the (more substantial-looking) bill by Gerald Frost on the N. American Stop Press. Mike Boatwright has forwarded Erik's latest critique to ID Frontiers where he still feels it looks OK for Greater:

Erik Hirschfeld- September 9 at 2:01pm

I made my first statement on the identity after seeing just a few pictures but I have now had time to go through all of those posted on the internet that I know of. I admit that on some, the bird looks more like a Lesser Sandplover and on others more like a Greater Sandplover. I wish I could see the bird for myself as it is always difficult to create an opinion from just photos. I do not follow this group and will be unaware of responses unless I am contacted directly (preferably via Facebook).

A series of shots is found here.


http://birdtrek.smugmug.com/Animals/Birds/SandPloverVA2009/9568310_w5mm7/1/643504800_jcKNB#643505797_4hgA7


They are useful as they probably are taken around the same time, in the same light conditions and are likely to convey an (on average) true feeling of the bird, which would be difficult with just single images taken under different conditions.

When I look at them, I still think this is a Greater and here are my reasons
therefore:

1. The size. This is a large bird (cf the Semipalmated Plover in one of the photos)
2. The jizz. I get an association with Grey Plover for Greater and Kentish Plover for Lesser. Greater is better balanced, with as much body behind as in front of the legs. Lesser is more front-heavy, with more body in front of the legs. A series of photos is necessary for determining this, as just a single image may freeze the bird in an untypical stance.
3. The bill. Look at those pictures which seem to depict the bird straight side-on, without turning its head towards or away from the photographer. It has a heavy bill, in my opinion heavier than a Lesser's. (A razor-sharp image of the bill would be desired though to look more closely at the exact shape, please let me know if there is one).
4. The primary wingbar. It appears that the amount of white increases towards the outer primaries, creating the "bulge" effect of the white which Greater shows.

The head shape is more indicative of Lesser, it seems quite rounded on most pictures while Greater usually (i. e. not always) has a more squarish head shape. There is some variation in this though and it cannot be used as a definite character.

It would be great if those in favour of Lesser (especially Lee and Killian whose knowledge I respect highly) could list exactly why they think so using the same series of photos referred to above. I can be mistaken of course, but I need to be convinced before admitting it :-)!

Erik Hirschfeld, Malmo,Sweden

[joemorlan]

Yes, thanks. I saw that on ID Frontiers.

But looking at the excellent profile posted here:

http://www.surfbirds.com/media/gallery_photos/20090908125751.jpg

...and comparing to the sketches on page 169 (Figure 7) of the paper in British Birds by Hirschfeld et al. it seems to me the proportions are better for Lesser. That is, the distance between the rear of the eye and the base of the culmen appears to be marginally less than the exposed bill length. More significantly, the length of the nail from the tip of the bill to the saddle seems short compared to the the rest of the bill.

Do you see it the same way?

[Brian S]

It is interesting to read the above comments and those on ID-frontiers.

In response to Erik Hirschfield's remarks on size, William Leigh wrote, 'I was able to view the VA bird on both Sunday and Monday and it never really ever showed that kind of height difference [between it and Semi Plover]. Instead it was definitely larger then the Semi but nothing dramatic.' So perhaps there is some size distortion in the photos.

If you zoom in on the bill it does look large (obviously, but you know what I mean), but slowly zoom out and the jizz changes, the bill becomes structurally more proportionate. I tried to convince myself that the feathers at the base of the bill were muddy or missing, again making the bill look bigger basally, but can't honestly tell. The reason I thought this was that the white on the malar region, where it meets the bill often projects forwards beyond that of the loral feathering and even reaches a point level with the base of the nostril - as here http://www.netfugl.dk/pictures.php?id=showpicture&picture_id=22341 and here http://www.netfugl.dk/pictures.php?id=showpicture&picture_id=1604 - note the bill looks stubbier on the first image. On the Virginia bird it looks odd....

Perhaps the tip of the bill is a little pulled out/pointed, but if this had been claimed as a Greater, there would be an equal discussion trying to tell us it was a Lesser. Some links to images of Greater of the three races.

crassirostris http://www.netfugl.dk/pictures.php?id=showpicture&picture_id=28965

Swedish GSP http://www.netfugl.dk/pictures.php?id=showpicture&picture_id=22342

Oman GSP (crassirostris?) http://www.netfugl.dk/pictures.php?id=showpicture&picture_id=19790

Columbinus - Cyprus GSP - http://www.netfugl.dk/pictures.php?id=showpicture&picture_id=9327

leschenaultii http://www.hkbws.org.hk/BBS/viewthread.php?tid=8532&extra=page%3D1 and here http://www.hkbws.org.hk/BBS/viewthread.php?tid=6350&extra=page%3D5 - check out the bill on the second photo.

Brian S

[Frostbyte]

Welcome to the forum Frostbyte and congrats on seeing a terrific state bird.

Thanks Joe, that's a good profile shot of the (more substantial-looking) bill by Gerald Frost on the N. American Stop Press. Mike Boatwright has forwarded Erik's latest critique to ID Frontiers where he still feels it looks OK for Greater:

Thanks for the kind words Andy. As my forum nickname suggests I am the same "Frost" that uploaded the photo. It is a miracle that the photo is of any value at all as it was hastily digiscoped, using another birder's scope, in heavy rain. Admittedly it is the only useful shot I was able to get at all, nonetheless I think it gives a faithful representation of bill profile. Most photos I have seen depict the bill at an oblique angle. Further, the vantage point from which (all?) photos have been taken is at a considerably higher elevation than the muddy pond banks. With these points in mind, most "profile" photos are oblique to some degree, making the bill appear shorter and/or thinner than a perpendicular view would reveal. My first reaction on seeing the bird in person was that the bill was much larger than it appeared in the photos I had seen beforehand.

As others have suggested, it would be wonderful to introduce some *quantitative* metrics of the bird's physical attributes, evident in photos, to help draw a conclusion. Tarsus:bill length ratio has been suggested as a useful metric (e.g., Millington 1988). As many have pointed out, bill size is quite variable in both species, but it seems to me that the ratio of bill length to the distance between bill base and the back of the eye could nonetheless be useful. I have determined these ratios for my photo, and intend to repeat the exercise for other photos of the Staunton bird, as well as other good profile shots of known Sand-Plovers (particularly, long-billed Lessers). For what it is worth, I come up with a ratio of 1.68 for tarsus:bill length, and 1.43 for bill length:bill base to back of eye. For the first ratio, Millington reported ranges of 1.43 - 1.78 for Greater, and 1.70 - 2.16 for Lesser. The second ratio I calculated indicates the bill is nearly half again as long as the distance from bill base to back of the eye.

Needless to say this method is not without shortcomings, and needs replication (more photographs, and more observers) using appropriate profile photos. But I think it a direction worth pursuing. Based on my field observations, and available information, I feel sure it is a Greater but would dearly love to see more consensus on this question.

[JanJ]

The video:

http://www.youtube.com/watch?v=tlBXJyK2tPw

JanJ

[joemorlan]

Erik Hirschfeld has permitted me to post the following additional
communications:

"Hi Joseph, Nice picture but it still is unsharp, so, as you say, the nail
length seems short, I agree on that. But, look at the total length of the
bill, it is long. And it seems sharp and pointed rather than blunt like a
Lesser (see that on the drawings in the BB feature as well)Have you seen
the video on http:/www.youtube.com/watch?v=IKrDO1EHHrs ? I think it looks
horizontal and large like a Greater. Even if the quality is poor, it gives
a good impression of what the bird actually looked like when it moves, much
better than single photos can do..... I am usually not a stubborn guy, but
this does not feel right for a Lesser! Let me know what you think. All the
best,
Erik"

.....

"Hi Joseph, Yes, you can share my comments of course, anything to further
the debate which is a good learning experience for all of us. I would be
careful with interpreting the summer plumage as I believe some have done,
as the bird is in moult and what remains is worn. This would also indicate
that it cannot be a columbinus, they are usually in full winter plumage by
mid August, having different moult timings than
crassirostris/leschenaultii. It seems that most US birders think it is a
Greater, while some European birders are in favour of Lesser. If any good
arguments for the latter turn up, please let me know.All the best,
Erik"

[CAU]

As others have suggested, it would be wonderful to introduce some *quantitative* metrics of the bird's physical attributes, evident in photos, to help draw a conclusion. Tarsus:bill length ratio has been suggested as a useful metric (e.g., Millington 1988). As many have pointed out, bill size is quite variable in both species, but it seems to me that the ratio of bill length to the distance between bill base and the back of the eye could nonetheless be useful. I have determined these ratios for my photo, and intend to repeat the exercise for other photos of the Staunton bird, as well as other good profile shots of known Sand-Plovers (particularly, long-billed Lessers). For what it is worth, I come up with a ratio of 1.68 for tarsus:bill length, and 1.43 for bill length:bill base to back of eye. For the first ratio, Millington reported ranges of 1.43 - 1.78 for Greater, and 1.70 - 2.16 for Lesser. The second ratio I calculated indicates the bill is nearly half again as long as the distance from bill base to back of the eye.


I measure the ratio tarsus/bill length to be 1.80 based on your photo (see the attachment). It seems like measurements are not too easy to perform based on photos.

Edit: I performed the same measurement on two photos from here (http://birdimages.posterous.com/staunton-va-sand-plover-images)(taken by Phil Davis, hopefully he doesn't mind that I have attached the pictures showing how I performed the measurements). I get a result of 1.83 for the first picture and 1.84 for the second.

[Brian S]

Those interested in this ID debate must check out Killian Mullarney's post on BF

http://birdforum.net/showpost.php?p=1583147&postcount=31

Brian S

[Colin Key]

Those interested in this ID debate must check out Killain Mullarney's post on BF

http://birdforum.net/showpost.php?p=1583147&postcount=31

Brian S

I have no experience of either species but have followed the debate because of my interest (and scepitcism!) in identifying birds from photographic images. I think that even the best of shots of this bird are very poor and I am surprised that no-one ventured forth with a DSLR and long lens to get some good images of this bird, given its potential rarity status.

I read Killian's post on BF earlier today, as well as the opinions of other "heavyweights" and those that have actually seen the bird. Interesting discussion and viewpoints!

I spent a bit of time yesterday looking at published work, web images, and comparing them to the bird in question and decided that I could not, or would not, be able to call this bird.

Is there a point in time when we just have to say "this bird is unidentifiable based on the evidence in front of us"? I just have the feeling that with images of this quality it is possible to see what we want to see rather than what is there :err:.

Colin

[JanJ]

I don´t know how many hours I´ve spent looking at the Virginia sand plover, and failed over and over again to be able to come to a conclusion. A mission impossible if not sharp images are provided!

Interesting with sand plover bills, apart from species and racial differences - the different impression from the same individual in different images, like in this swedish Greater:

1. http://www.pbase.com/slisch/image/99611704
2. http://www.pbase.com/slisch/image/99432546
3. http://www.pbase.com/image/99629916

Also the nail lengt - which seems to be a rather consistent feature in sand plovers - is difficult to judge from images in unsharp images, in birds with mud on there bills etc.
No doubt in the swedish bird which part of the bill is the longest. Which leads me to the image of the Virginia sand plover linked in Killian's first set, on which he has measured the bill-length - bill to eye ratio. In that image the lenght of the bill is approx. the same as the lenght from the bill base to behind the eye, which in favour of Lesser. Furthermore, the nail lengt seems to be shorter than the basal part of the bill, also in favour of Lesser.

What about this one then?

http://www.pbase.com/ingotkfr/image/92920248

JanJ

[Frostbyte]

[QUOTE=CAU;17656]I measure the ratio tarsus/bill length to be 1.80 based on your photo (see the attachment). It seems like measurements are not too easy to perform based on photos.

Nice job superimposing lines to indicate your measurements, I should use different software so as to do the same. I do question the tarsus measurements a bit, in that you measure from the rear of the knee, to the *front* of the tarsometatarsal joint. I am not sure this is comparable to what might be obtained using calipers (alas, if calipers had been applied to this bird...we wouldn't be having this discussion!) and would give an overestimate. For what it is worth, another Virginia birder (D. Schoch) has gone through the same process, I insert his results from another site below:

To kill some time I looked again at a selection of profile shots to roughly measure tarsus to bill length ratio, referencing Millington 1988 (quoted in Howell et al 2001), with Greater ranging from 1.43-1.78 and Lesser from 1.70-2.16. With n=9, the mean was 1.61 (range: 1.50-1.87), the mean will within the range of Greater; only one value exceeded the range for Greater, and only two values were within the range of Lesser.

Indeed, more replication and a standardized protocol for the measurements are needed. Also there are obvious shortcomings to using photo-derived measurements, among them the difficulty of distinguishing oblique views from profile views. Given that many of the photos are not of, shall we say, magazine quality, subtle features and depth perception are compromised and I feel it is easy to confuse oblique photographs. As an example, K. Mullarney measured bill length ratio using one photograph and determined bill length to be "significantly" shorter than distance to back of eye. I do not question his measurements within the photo, but the ratio derived from the photo simply does not square with my field observations of the bird.

Had I not seen the bird myself, I would be hard pressed to take one side or the other. Still, two of my conclusions after observing the bird were that the bill susbtantially exceeded the distance from back of eye to bill base, and the bird was clearly larger than Semipalmated Plover in direct comparison. I had hoped to view the bird next to a Killdeer, but alas, cooperation was not forthcoming. With these statements in mind, I am eager to hear the impressions of others who saw the bird.

In any case I doubt consensus will be reached on this bird - perhaps the photo-derived measurement ratio approach offers the only defensible approach, warts and all. One thing for sure, I would far prefer to be shown wrong, than see this exceptional rarity go "unidentified" practically in my own backyard.

[Martin Garner]

Following a request from Gail Mackiernan last night and subsequent help from Michael Boatwright today in accessing some of the full range of images I think this bird can be identified as a slam-dunk Mongolian Plover. Hopefully these comments are useful and clear enough to follow. From here on I will refer to Greater Sand Plover (generically all forms), Lesser Sand Plover (atrifrons/pamirensis schaeferi) and Mongolian Plover (mongolus/ stegmanni).
My ‘first off’ impressions of this bird are that it does suggest a Mongolian Plover. I know that sounds perhaps a bit over-confident, but that was my gut reaction based on the summer ‘breeding plumage’ still present on head and body (not normally OK for Greater Sand in September) and the bill/ head proportions and the slightly greater ‘rangyness’ compared to Lesser SP; Greater always shows this slightly overlong look to the bill, which seems a product both of the overall bill length and the long nail (though it can be hard to describe) and I just don’t see a Greater SP bill here. All of the UK records for Lesser/Mongolian Sand Plover have begun as ‘Greater Sand Plover’. I also saw a Greater Sand Plover in Cumbria, England in 1988 which was hotly debated at the time and was thought originally to be a Lesser. All kinds of formula/ photos and measurements were used with this latter bird by proponents of its identification both as Greater and Lesser Sand Plover. The mathematical formulas (bill/ eye, head/ bill, bill/ legs etc) seem to have a tendency to be difficult to apply and a reputation for cancelling one another out as the photographs of birds don’t provide empirical data (like biometrics), so while they can be useful sometimes, so I would prefer to focus to other approaches.

To the Virginian bird:


1) Head and Body plumage

It shows clear remnants of worn and moulting summer ‘breeding plumage over the head and especially the underparts. Greater Sand Plover normally undergo at least head and body moult prior to leaving the breeding grounds, so by September should appear to be in ‘winter plumage’ with a few feathers in areas such as wing and tail still to be moulted. Any sand plover still retaining some obvious element of ‘breeding plumage’ to the head and body in August and September will normally prove to be a Lesser or Mongolian Sand Plover. There may be exceptions in regard to moult and vagrants sometimes (though none that I know of), but better to start with the norm.

2) Bill

I agree with other commentators that the bill looks fine for Lesser/Mongolian and I don’t see the slightly ‘clownish’ long nail and bill proportions of Greater. Those who also consider the head and bill to be more Lesser -like have already done a thorough job of attempting to explain why, so I don’t need to attempt to repeat that, suffice to say I agree with Killian Mullarney’s assessment on ID Frontiers and (with photos) on Birdforum.

3) Overall structure

In some shots it looks a long-legged rangy bird. This is subjective but I think Mongolian (versus Lesser) has greater tendency to look rather rangy and sometimes ‘large’, which is maybe why there is a greater tendency for Mongolian to be confused with some Greater S P’s. Mongolian is intermediate in size between Lesser and Greater. In, for example wing length, Mongolian overlaps considerably with Greater, whereas Lesser for the most part does not: Wing length: Greater S.P. = 135 - 155mm, Mongolian S.P. = 128 - 146, Lesser S.P. = 120 - 137.

4) Leg colour and length.

Some myths persist over characters related to the legs of sand plovers, which should be laid to rest. The leg colour in all forms of sand plover is variable. Mongolian Sand Plover frequently show long-looking greenish legs. The only useful comment that might be made in regard to leg colour is that very black legs do not normally seem to be found on Greater Sand Plover. Otherwise any combination of grey though greenish can be found on any sand plover. In regard to extension of the toes beyond the tail, Mongolian can show this, no problem.

5) Tail Pattern.

There are a several shots showing the tail pattern. The darker central tail feathers are found in Mongolian and Greater Sand Plover but not as far as I know in Lesser Sand Plover (pattern is paler and more uniform).

6) Flanks
This seems to have been barely touched on. While I wish the photos resolved better and were less blurry I can see non-white feathers on the flanks on both sides of the bird. They look pale greyish brown and create a slight ‘grubby’ area here. The feathers are on that area of the flanks that butt up to the normal folded wing position and so can be (partly) obscured by the wings. In fact photos with raised wings clearly show there is more dark rear flank feathering hiding under the folded wing. Also because the grey-brown colour on such flank feathers is weak and somewhat translucent –looking, it is not very striking and has to be ‘looked’ for. In these photos it is hard because of the distance and quality of the images. Nevertheless, it is clearly visible on this bird in a number of photos, and I hope others can see it too. (Maybe someone with high quality field notes/ drawings has recorded this). In some shots it just looks like vague browner wash on flanks just below the folded wing but on a few photos (e.g. those by Phil Davis), clear darker-patterned feathers can be seen blowing up against the folded wing (on both flanks of the bird). This is diagnostic for Mongolian being found in 60-70% of birds in winter plumage and so should be expected but not guaranteed. It is not found in Greater or Lesser SP. On Greater and Lesser Sand Plovers the flanks are gleaming white. Occasional ‘fluffed –up’ feathers can look a bit darker as they overlap the brown wing coverts and the colour of the latter ‘shows though’ but that artefact should be discernable as such nonetheless.

Conclusion

So I see a combination of state of moult (pro Lesser/ Mongolian); bill proportions (pro Lesser/Mongolian); tail pattern (pro Mongolian/ Greater); and dark mid/rear flank feathering (diagnostic of Mongolian) giving me confidence that, while the features are subtle and have to be carefully read in the various photos, in their combination, the bird can indeed be identified as a Mongolian Plover.

[Johnny X]

I'm interested by the suggestion that Greater Sandplover shouldn't show remnants of summer plumage in September.

Last September, the Ythan Estuary, NE Scotland was graced by a non-controversial Greater Sandplover...to my eyes it clearly showed some features of summer plumage. You can see this a bit in photos e.g. http://angusbirding.homestead.com/Greater-Sand-Plover.jpg, but i recall it being more obvious in the field.

[Johnny X]

I see that Howard King has provided information that this is fairly normal for autumn Greaters in Bahrain - http://www.birdforum.net/showpost.php?p=1584587&postcount=40.

[JanJ]

Some good suggestions provided by Martin. Just a quick wonder about the Mongolian suggestion, regarding the bill dimension.
I was under the impression that the mongolus group (Mongolian Plover) is the shorter-billed compared to the atrifrons group (Lesser Sand Plover), which is longer-billed or slimmer-billed. Given the range of Mongolian one can perhaps expect records from western N. America being of this species. However, the bill of the Virginia sand plover has a bill lenght which in my opinion oversize a Mongolian and perhaps better fits one of the other ssp of Lesser Sand Plover, perhaps this race:

http://shorebirds.exblog.jp/pg/blog.asp?eid=c0071489&iid=12&acv=&dif=&opt=1&srl=3832543&dte=2006%2D04%2D25+23%3A05%3A00%2E000

I realise that in Mongolian/Lesser variation in bill size also can be indipendant of race/species, more on individual variation basis and perhaps according to age. Which brings me to the next question. Is the plover correctly aged?
Peter Pyle suggest a 2cy bird with heavily worn wing coverts. Has this been confirmed?

When Martin mention that all Greater has a the 'overlong looking bill' he of course referes to leschenaultii and crassirostris and excluding columbinus, which then would make this one a crassirostris (also on plumage features). Not the oversized bill of a Greater I would say. Note that the nail is longer than the basal part, even if the impression from this image might suggest equal length:

http://www.pbase.com/slisch/image/99432546

I must say, the more I put myself into the learning process the more confused I get.
Reading Erik's et al great paper is a real eye openar, since I´m a bit of a novice when it comes to sand plover identification. I fully understand the complexity ragarding these two/three species, and have seen only a handfull myself of Greater and Lesser.

JanJ

[CAU]

Nice job superimposing lines to indicate your measurements, I should use different software so as to do the same. I do question the tarsus measurements a bit, in that you measure from the rear of the knee, to the *front* of the tarsometatarsal joint.


I don't know how the measurements performed by Millington were made, but I tried to replicate the standard way how the tarsus of a bird is measured. Here's Pyle's (2008) description:
"The most widely taken measure refers to the distance between the notch at the at the end of the lateral condyle of the tibetotarsus, on the back side of the leg, to the last undivided tarsal scute on the front of the leg, taken at a slight angle to that of the tarsus."

However, I agree with Martin Garner that measurements based on photos most probably won't yield any conclusive data, I only presesnted my results to show this (and we're really comparing apples to oranges if we compare measurements taken from photos to measurements taken from live birds or skins).

[Frostbyte]

The Virgina sand-plover is indeed quite a shape-shifter in the various photos we have all pored over. I am baffled by the range of apparent bill proportions. That said, I have a tough time reconciling the "large-billed" shots with ssp. stegmani/mongolus.

So, how about some more photos. Here is a link to another set of photos posted by Allen Bryan which were first referenced earlier today on the local Virginia rare birds listserv. Apologies if these have already made the rounds; I had not seen them before.

Taken together, I think these photos give the best comparative views to date of the bird next to Killdeer and Semipalmated Plover.

<http://www.visitingnature.com/sandploverspeciescompilation.htm>

[l_raty]

I don't know how the measurements performed by Millington were made, but I tried to replicate the standard way how the tarsus of a bird is measured. Here's Pyle's (2008) description:
"The most widely taken measure refers to the distance between the notch at the at the end of the lateral condyle of the tibetotarsus, on the back side of the leg, to the last undivided tarsal scute on the front of the leg, taken at a slight angle to that of the tarsus."

Millington's leg lengths were "from knee to foot" according to Hirschfeld et al. 2000 (which doesn't help a lot, I guess...).
FWIW:
Svensson (1975) : "from the notch on the back of the intertarsal joint to the lower edge of the last complete scale before the toes diverge".
BWP1 (1977) : "from the middle point of the joint between tibia and tarsus behind to the middle point of the joint between tarsus and middle toe in front of the leg".
So this seems pretty standard, indeed.

I'd actually have more problems with the bill measurements...
The bill lengths that were used to build Millington's formula were taken "from bill tip to where feathering meets culmen".
Where feathering meets culmen is probably impossible to discern with any precision on the available pictures of the VA bird. But, when head feathers are flattened, at least, this will typically not be in a direct straight prolongation of the forehead (which is where the red lines you have added to the bills on the three pics appear to stop).
Check Howard King's (sharp) LSp pics here (http://www.birdforum.net/showpost.php?p=1585168&postcount=49), for example, to get a sense of what you should be looking for. Then see Howard's interpretation of Frostbyte's picture here (http://www.birdforum.net/showpost.php?p=1584092&postcount=37)... The bill length you got from this pic probably exceeds by nearly 20% what one would get using Howard's perception of where the bill base lies.

[Frostbyte]

The bill lengths that were used to build Millington's formula were taken "from bill tip to where feathering meets culmen".

Based on this interpretation, then, my determinations of tarsus and bill length are in error. Thus I am inclined to think the bird probably is a Lesser, though I would like to see E. Hirschfeld weigh in following the analyses of K. Millarney and others.
Great learning experience in any case.

[o2birdVA]

I have posted 2 new images of the VA Sand-plover - links below - that may or may not show a bit more detail of the bill. One image was also zoomed 200-300% that shows the small hook on tip of the upper bill.

Comment on image quality: Distance (170+ feet), wind and limited area in addition of shooting down on the plover were contributing factors to difficulty in getting sharp images. Compound that with the fact individuals had to stand on layers of old, some rotten, vine-covered wood planks and crates that had been tossed up against the small open area along the fence. Vibration was a constant problem as individuals squeezed together and attempted to maintain their footing.

Image 1 - Profile
http://www.birdsofvirginia.com/ImageLinks/SandPlover17_Link.html

Image 2 - same image, only zoomed 200-300%.
http://www.birdsofvirginia.com/ImageLinks/SandPlover18_Link.html

Image 3 - front view
http://www.birdsofvirginia.com/ImageLinks/SandPlover19_Link.html

[Lucius]

Hi all

I found this poss Lesser sand in Sicily on 23 aug

the bird ID is quite problematic and I'd like to have your opinion

here the pics an videos from the Italian Birding forum
http://www.ebnitalia.it/public/forum/viewtopic.php?f=4&t=1477

my pics are in the first and in the last post

videos in the middle


this bird had a strange moult on wings with fresh inner primaries and faded outer primaries and secondaries

an evident moult on biggest scapulars


thanks a lot

Lucius M.

[Lucius]

I'm sorry

is not possible for visitors to see pics and videos on the italian birding forum without permit.

so I uploaded 2 photos and 1 video on Flikr


http://www.flickr.com/photos/42580073@N07/


Lucius M.

[Colin Key]

Now thought to be a Kentish Plover:

http://www.birdforum.net/showthread.php?t=151101&page=4

Colin :cool:

[MichaelF]

Kentish as distinct from Snowy Plover (i.e., Eurasian subspecies, not American subspecies, of Kentish)?

[AndyB]

Just so we clear, the ID of Kentish Plover is referring to Lucius's bird in Italy:
http://www.flickr.com/photos/42580073@N07/
and not the Sandplover in Virginia.

[Colin Key]

Just so we clear, the ID of Kentish Plover is referring to Lucius's bird in Italy:
http://www.flickr.com/photos/42580073@N07/
and not the Sandplover in Virginia.

OOOOPS!!!

Apologies for this; I read and re-read the last few posts on BF and thought that there was something odd in Killian's apparent change of opinion - I just did not pick up that it was a different bird being referred to.

Colin :notworthy:

[Howard King]

I have posted 2 new images of the VA Sand-plover - links below - that may or may not show a bit more detail of the bill. One image was also zoomed 200-300% that shows the small hook on tip of the upper bill.


Still of the opinion that its a Lesser Sand Plover