The first-summer female Sand Plover at Rimac May 11-13th 2002

Lesser Sand Plover - Rimac 12th May 2002 © Mike Tarrant

The debate over the specific identification of the sand plover found at Rimac by Mike and Steve Tarrant and Barrie Clarkson quickly suggested that the bird was not a Greater Sand Plover but in fact Britain’s second ever Lesser Sand Plover. I have to admit that at first I was sceptical my opinion being based mainly on the birds apparent large size compared to the accompanying Ringed Plovers. It should however, be born in mind that some of the Ringed Plovers present at the same time could have been migrants and thus birds approaching tundrae in size rather than local hiaticula. The individuals nesting on the shingle ridge, which attacked the Sand plover on the 12th would of course be nominate birds.

The following is not an in depth analysis but a quickly written personal opinion that opens the way for further discussion. Please feel free to contribute to the ongoing argument!

Having now had chance to study the paper in British Birds, Identification, taxonomy and distribution of Greater and Lesser Sand Plovers by Erik Hirschfeld, C.S. (Kees) Roselaar and Hadoram Shirihai (BB 93 No 4 April 2000 p 162-189) I consider that the photos of the bird do indeed confirm that it was a Lesser Sand Plover.

To take the vital points in order:

Jizz and structure: EH et al state: "Greater Sand Plover is the larger looking of the two. In side view, it has a proportionately large eye situated in the middle of the head, which appears more square than Lesser’s with a flat crown. The long legs are well balanced by the attenuated rear, and the bird’s weight is more evenly distributed in front of and behind the legs. Greater usually has a more horizontal stance and body shape, and can often recall a small Grey Plover.

On Lesser, the head is smaller and more rounded, and the eye is situated closer to the bill. The legs can look long, but the impression is still that there is more `weight’ in front of the legs; the area behind the legs looks less attenuated and much less `massive’ than that in front".

Profile shots of the Rimac bird seem to conform to the weighty front end when alert, resting and feeding. Although often looking hunched the crown always appeared to be rounded.

I have attempted to calculate the formula of bill length to tarsus length from the best side on profile photos. My calculations result in a ratio of 1.95 which according to EH et al firmly puts the bird into the range of Lesser even being at the upper end of that species range. Average ratios of Greater are noted as 1.55 to 1.66 with Lesser 1.86 to 1.98. Similarly Millington 1988 proposed ratios of 1.59 to 1 for Greater and 1.85 to 1.99 to 1 for Lesser.

Leg colour was generally agreed to be dark greyish on the Rimac bird. In very good light I thought I detected a slight greenish tinge. This is noted as a supportive ID criteria by EH et al.

The length of the nail (the swollen end) on the bill in proportion to the base is given as an important ID feature. On Greater the nail is always longer than the base whereas on Lesser it is the other way round. This is said to contribute to the blunt-ended impression given by Lesser. It is a conclusive feature when measured in the hand. From the best profile photo I have posted I suggest that it is possible to establish where the nail starts on the bill. It appears to me to form the distal 35-40% of total bill length. I also noted this in the field on close scope views. This would also suggest that the bird is a Lesser.

Tail pattern is another quoted feature. Greater generally shows an obvious darker sub-terminal tail band whereas on Lesser the tail is evenly sandy-brown. On close views I failed to detect a sub-terminal tail bar on the Rimac bird in fact its tail looked very uniform in the centre.

Foot projection beyond the tail is given as another supportive ID character. There will no doubt be differing views on whether the toes did project which may be answered by video stills or close up flight photos. When watching the bird in the scope on the 12th I did see it take off at an obtuse angle from a position that was slightly elevated in relation to my position. The tip of the tail was certainly visible covering the feet totally on this occasion but whether the distance of the flight may affect leg positioning may be open to question.

Graham Catley

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