Is it possible that a small plover, not described or illustrated in any modern literature or field guide occurs in southeast Asia? This is the question we were faced with following sightings of several small Charadrius plovers in Malaysia and Singapore.
Observations of Javan Plover were made in March 1994 at Muara Angka, a reserve lying on the outskirts of Jakarta, Java, where several pairs of javanicus were breeding, and one nest was located. These birds were quite different in appearance to ‘White-faced’ Plovers, being dark brown to sandy-brown above, quite similar in colour to typical Kentish Plovers, while the males showed a warm rufescent-brown wash to the lower crown, rear of the supercilium, and behind the ear-coverts. Furthermore, the lores were entirely dark, the patches at the sides of the breast were rufescent-brown, not black, and the legs were dull greenish-grey. In addition, Javan Plover is a small bird, similar in size and structure to seebohmi and Malaysian Plover, and distinctly smaller than ‘White-faced’ Plover. This combination of characters eliminated Javan Plover from those taxa under consideration.
Figure 11. Male Javan Plover, Sulawesi, Indonesia. Both sexes of Javan Plover remain relatively nondescript throughout the year, and although the male does not develop a strongly patterned plumage it does appear brighter and the head pattern is crisper than that of the female. On this fairly well-marked male, the frontal bar, ear-coverts, lores and lateral breast patches are dull russet-brown rather than black as in Kentish Plover. In addition, the uniform upperparts are quite different to the variegated upperpart appearance of Malaysian Plover. Note the pale legs which are also a feature of many ‘White-faced’ Plovers, particularly females, Pete Morris/Birdquest
Figure 12. Female Javan Plover, Sulawesi, Indonesia. Both sexes show a well-marked brown loral line and extensive lateral breast patches, but this female Javan Plover lacks the russet tones of the male. Javan Plover is relatively small, overlapping in size with Malaysian and seebohmi Kentish Plovers, and is significantly smaller than ‘White-faced’ Plover. Pete Morris/Birdquest
Although it seemed unlikely, the possibility of Red-capped Plover C. ruficapillus from Australia and White-fronted Plover C. marginatus of southern Africa was considered. Both species are quite different in appearance to ‘White-faced’ Plover and, in particular, lack the white neck collar and display dark lores. Again, it proved impossible to find any known plumage of any species which matched that of ‘White-faced’ Plover.
After reviewing published accounts and descriptions of the various races of Kentish Plover and other small Charadrius plovers we are still unable to find any that match the distinctive features shown by ‘White-faced’ Plovers. With all recognised taxa eliminated, we considered the four most likely remaining options; that they could represent a hybrid (perhaps between Kentish and Malaysian Plovers), an aberrant plumage of a commoner species, a poorly known race of one of the commoner species or an undescribed taxon. Photographs and observations of at least 20 individuals, including birds of both sexes in breeding and non-breeding plumages, have established that all showed a consistent suite of structural, morphological and plumage characters that are at odds with the hybrid and aberrant plumage options. Although unlikely, we are investigating the possibility that these birds may have previously been described but have somehow been overlooked or subsumed within a widely recognised species. The final option is that they do represent an undescribed taxon. On-going research should establish which of these alternatives is correct.
Although we have made an extensive search in the literature and trawled through the internet for images of ‘White-faced’ Plovers, only two or three other ‘sightings’ have come to light. The first was made by Chris Rose, who sketched a male in breeding plumage at Kapar Power Station, Selangor, Malaysia, in March 1993 (and mentioned by Wells 1999). The second involves at least two birds and possibly more, photographed by Jonathan Cheah at Changi Cove, Singapore, on 12th February 2007 (See the first two images here). Finally, Hanno Stamm posted a photo showing a male 'White-faced' Plover taken on 20th November, 2007, at Phan Thiet, South Vietnam at this link (rear sitting bird).
Images showing what appears to be a female Kentish Plover, but with an atypical rufous-brown wash to the crown, ear-coverts and lateral breast patches, and pale pinkish-grey legs, was photographed on Okinawa, Japan, on 20th March 2002. These can be viewed at here then go to Kentish Plover, March 2002 Okinawa Pref. (2). A similar bird showing a rich rufous-brown wash to the crown, ear-coverts and lateral breast patches was observed in Hong Kong in April 2007 (PRK pers obs.). In addition, a juvenile bird, possibly a ‘White-faced’ Plover, was photographed at Sok Kwu Wan, Lamma Island, Hong Kong, on 15th October 2007 by Neil Fifer. An image of this bird appears at: HKBWS
In both these cases, however, the lateral breast patches are larger than we would expect of ‘White-faced’ Plover.
Rather than provide a comprehensive plumage and bare-part description based upon field observations and photographs, comparative details of typical Kentish and ‘White-faced’ Plovers, based upon observations of these species when seen together, are detailed below. It is considered that this will provide a more digestible format to compare these taxa. Features which appear to differ significantly between Kentish and ‘White-faced’ Plovers are emphasised in italics. Where appropriate, comparison with Malaysian Plover is made, although it is emphasised that this species was not seen together with ‘White-faced’ Plover. Although observations revealed that one or two birds showed pale buff fringes to the wing-coverts, which may have been the retained juvenile plumage, it is considered unwise at this point in time to attempt to age ‘White-faced’ Plovers using this feature. The comparison of birds in non-breeding plumage, therefore, includes both adult and juvenile birds.
The shape and structure of ‘White-faced’ Plover is quite different to that of Kentish Plover. They appear slightly larger than Kentish and display a consistently larger headed, heavier breasted and flatter backed appearance. In addition, they have a proportionately longer and slightly heavier bill than Kentish; this appearance in part being due to the ‘nail’ being deeper and extending closer to the bill base. The legs, and in particular the tibia length, are also proportionately longer than those of all other smaller Charadrius plovers in southeast Asia.
Figure 13. ‘White-faced’ Plover (right) with a Kentish Plover, Penang, 21st November 2006, showing the marked difference in upperpart colour. Structurally, ‘White-faced’ looks larger-headed, longer-legged, heavier-billed, flatter-backed and heavier breasted than Kentish Plover. David Bakewell
Until the moult into breeding plumage, the most obvious difference between Kentish and ‘White-faced’ Plovers lies in the overall upperpart colouration.
Mid brown. Mantle and scapulars plain mid brown with darker shaft streaks. Coverts similar but with buff-brown fringes.
Pale sandy-brown. Mantle and scapulars variable. On some birds, completely plain; others with darker shaft streak and narrow paler fringes. Coverts; median and greater coverts plain or narrowly fringed buff. Lesser coverts, especially the outermost, quite broadly fringed whitish. Note that the birds with buff fringes to the coverts may have retained juvenile plumage.
Seen at a distance, upperpart colouration alone would not necessarily rule out a bleached or exceptionally pale Kentish Plover. In addition, Kentish Plovers of the race seebohmi in Sri Lanka can appear as pale as ‘White-faced’ Plover, but usually are duller, rather colder and distinctly smaller.
Lateral breast patches
Another useful and probably diagnostic difference occurs in the shape and extent of the lateral breast patches.
Some birds (females?) show quite wide (deep) lateral breast patches, a feature not shown by any ‘White-faced’ Plovers present. Others show narrow breast patches similar in width to ‘White-faced’ Plovers. Regardless of width, the breast patches are longer than on ‘White-faced’ Plover, extending further round towards the breast centre. Seen from head on, the length of each breast patch is usually longer than the white space between them. It should be noted that the lateral breast patches on Kentish Plover do occasionally meet to form a complete band across the upper breast (Chandler & Shirihai 1995; Leader 2001). See first image at Oriental Bird Images
The lateral breast patches are narrower and shorter than on Kentish. Seen from head on, the white space between the breast patches was longer than the length of each breast patch.
Figure 14. Note the broad bill base and entirely white ‘face’ and forehead as well as the short lateral breast patches.. David Bakewell
The white underparts of ‘White-faced’ Plover seem more striking than on Kentish. This is perhaps because of the more restricted lateral breast patches and the white on the face and forehead being more extensive than on Kentish. Add to this the overall paleness of the upperparts of ‘White-faced’ Plover and the effect is to make them appear much paler than Kentish. This is particularly apparent when viewing both species at a distance.
Quite variable in both species.
Both sexes of Kentish Plovers are similar in non-breeding plumage and show no rufous tones anywhere on their plumage until they begin their moult into breeding plumage, when the rear of the crown begins to show rufous tinges (from late December onwards). In this plumage, the brown ear-covert colouration on Kentish Plover is more extensive than on ‘White-faced’ Plover, coming down well below eye level.
Generally, ‘White-faced’ Plover show more white on the forehead than Kentish, and more white on the ‘face’ overall. The loral area is paler on ‘White-faced’ Plover, being largely white on some birds (males?), with faint dusky feathering around the lower edge of the eye. This gives them a ‘white-faced’ appearance, with the eye and bill appearing more prominent relative to Kentish. ‘White-faced’ Plover shows faint rufous tones on the rear-crown, nape and rear ear-coverts between October and December. On some birds this feature is quite marked and on others, barely discernible. This rufous colouration begins to brighten to orange on males from late December onwards as the pre-breeding moult starts.
Figure 15. Male ‘White-faced’ Plover, Penang, 21st November 2006. The same male as depicted in figure 14. Non-breeding plumage. On this bird the beginnings of a black frontal bar can be seen on the fore-crown. David Bakewell