In Peninsular Malaysia, Little Stint has been shown to be a scarce but annual passage migrant and non-breeding visitor, with more than 140 records between the late 1980s and the present, most in the last 12 years (See Table 1).
So, it’s a species which is long overdue in Singapore. The main obstacles to the addition of Little Stint to Singapore’s list of avifauna have, in the past, been lack of awareness of identification criteria to differentiate it from Red-necked Stint, and, in recent years, lack of accessible and suitable areas of stint-friendly habitat.
Nevertheless, people have been looking, probably none more so than David Li, from whom I received a series of photos in September, asking me what I thought. With his permission, I reproduce my thoughts below, together with his photos.
Comments on putative Little Stints at Check Jawa, Pulau Ubin, Singapore, on 21 Sep 2017
David sent me several images of a small group of waders he photographed on 21 Sep 2017, asking my opinion on the specific identity of two of the birds. He suspected that one or both may be Little Stints.
The fortuitous presence of an undisputed juvenile Red-necked Stint with which to compare the two other stints is of great help in assessing these birds.
Having studied the photos sent to me by David, I am confident that both the birds in question are Little Stints. I will attempt to provide a rationale for this opinion below by examining the shape/structure and plumage of these birds in some detail.
SHAPE AND STRUCTURE
I have written couple of blog posts on the structural differences between Red-necked and Little Stint (https://digdeep1962.wordpress.com/2013/09/14/sungei-buloh-stint-a-little-odd-or-an-odd-little/ and https://digdeep1962.wordpress.com/2013/03/07/identification-of-an-odd-juv-stint-at-pak-thale-thailand/) , from which I have lifted the following summary.
Structure of Little Stint compared with Red-necked Stint
- Longer legs, both tibia and tarsus
- More finely-tipped bill, not as deep-based. Often subtly down-curved and longer.
- Smaller, rounder head which peaks at the forecrown, and slimmer neck
- Body shape rounder, less attenuated, with rounder ‘shoulders’ when feeding, and head seems to sit on top of the body, rather than in front
- Generally more upright posture
- Less ‘deep-chested’ (not so much in front of the legs)
Plates 2 and 3 clearly show a marked difference in leg length, with both the tarsi and the exposed tibia being longer on both birds in Plate 3 than the Red-necked in Plate 2. Where comparisons are available in the other photos, this difference is consistent.
The bill profile of the birds in Plate 3 shows a more tapered bill, with a finer tip, with a subtle decurve along the lower edge of the bill of both birds, compared to the rather thick, short, straight, thick-tipped bill of the Red-necked Stint in Plate 2.
As the birds are relaxed and hunched up, the head and neck shape is not as clear on these photos as on some others. Nevertheless, the birds in Plate 3 give the impression of having a smaller head than the Red-necked in Plate 2.
The rugby ball shape of the Red-necked body differs subtly from the rounder, football-shaped body of the birds in Plate 3, and the way the head connects to the body is distinctively different – on the Red-necked, the head seems to sit at the front of the body whereas, on the birds in Plate 3, it sits on top of the body. Little Stints often seem more ‘bosomy’ than Red-necked, and this difference can be seen here.
The differences described above can be seen in Plates 4-6. It is worth noting that the adult bird is missing a couple of tertials, which makes the rear end look longer and slimmer than it would otherwise appear. The upright posture of both birds is typical of Little Stint and not often seen in Red-necked.
Plate 6 shows the typical ‘round-shouldered’ posture of Little Stint on the adult bird. A Red-necked in similar posture would have a much flatter-backed profile (See Plate 7).
The structural differences described above are subtle, and possibly not diagnostic when taken separately. However, taken together, they present a distinctive appearance which readily separates Little from Red-necked Stint. In every respect, the two birds show structural features consistent with Little Stint and at odds with Red-necked Stint.
- The Juvenile
The following summary of plumage differences is taken from the same blog post referenced above:
Plumage of juv Little Stint compared with juv Red-necked Stint
- Scapulars and coverts evenly dark-centred, pale-fringed . Red-necked lower scapulars tend to have a dark subterminal spot with pale base, and rather bland, grey-centred, pale fringed coverts.
- Mantle often strikingly dark due to darker feather centres.
- Well-streaked breast sides. Red-necked has indistinct streaking and usually a greyish wash which extends across the breast.
- Well-marked head, with dark ear coverts and central crown and white ‘double supercilium’. Central crown of Red-necked not strikingly dark, and sides blend paler towards supercilium, offering little contrast with it.
Of the five rows of scapulars, the lower two are of critical importance in distinguishing Red-necked from Little Stint. On Red-necked, these are basally pale, with a dark sub-terminal spot around the shaft. On Little, they are more extensively black-centred, with any pale at the base covered by feathers above them. The differences can be seen in the Plates 9 and 10 below (from https://www.britishbirds.co.uk/wp-content/uploads/article_files/V77/V77_N07/V77_N07_P293_315_A085.pdf). The lower scapulars are marked with red arrows.
The distinctive pattern of Red-necked Stint lower scapulars can be seen on the left bird in Plate 8, and that of Little Stint on the right hand bird.
A similar difference is seen in the pattern of wing coverts on Red-necked (a darker shaft streak, with the centres shading paler toward the edges, offering little contrast with the fringes) and Little (evenly dark centres contrasting quite strongly with paler fringes. This can be seen most clearly on the largest coverts, the inner greater coverts (marked by blue arrows in Plates 9 and 10).
On Plate 8, the Red-necked Stint shows darker and more contrasting coverts than on Jonsson’s painting. Nevertheless, the pattern of dark shaft streak, and centres shading paler toward the edges is apparent. On the right hand bird, the centres are solidly dark – blackish, with no paler gradation toward the edges, a pattern typical of Little Stint but not Red-necked.
The mantle of the right hand bird in Plate 8 is strikingly darker than that of the Red-necked on the left, which is typical of Little Stint.
The streaking on the breast sides is more distinct on the right hand bird in Plate 8, and this difference is visible, together with the richer, less grey colouration, in other photos as well.
The head pattern of the two species in juvenile plumage is strongly distinctive. Unfortunately there are no head-on shots of the Red-necked Stint, but there are several of the juvenile putative Little Stint (e.g. Plates 11 and 12), and all show the strongly contrasting dark crown and ‘split supercilium’ which are indicative of Little Stint.
Thus, in all respects, both in structure and in plumage details, this bird is typical of juvenile Little Stint.
- The Adult
As is the case in juvenile plumage, the critical feather groups to look at include the scapulars, coverts and tertials and head.
This particular bird is in post-breeding moult, with most of the mantle and scapulars already in non-breeding plumage (two breeding plumage lower scapulars remain on the left hand side), the coverts are almost entirely cloaked by these new scapulars (one or two are visible in Plate 14), the tertials have been mostly dropped, with the remaining one being so worn as to show no fringing. The head and breast still retain a good proportion of breeding plumage feathers. Thus, most of the distinctive features one would look for in an adult breeding plumaged bird are missing, making it extremely challenging to identify on the basis of plumage alone.
The pattern of the old breeding plumage scapulars and coverts are suggestive of Little Stint but not strongly diagnostic. Similarly, the rather obvious dark shading around the shafts of the non-breeding plumage scapulars favours Little (on Red-necked, non-breeding scapulars tend to be paler, with dark restricted to the feather shaft) but falls short of being diagnostic.
The head and body plumage offer the best clues to the bird’s identity. A bird retaining this much breeding plumage around the head and breast would also show at least a few pink feathers in the throat area, as well as some darker smudgy marks on the front and rear flanks if this were a Red-necked Stint (see Plates 7 and 15). The fact that the throat and flanks are clear unmarked white on this bird strongly favours Little Stint.
As with juveniles, the central crown is darker and more clearly defined on adult Little Stint than on adult Red-necked (in all plumages) and there is a clearer split supercilium. This can be seen well in Plates 16-18.
Although the upperparts do not provide enough to arrive at a definite conclusion, the head and underparts, coupled with strong structural evidence, make the identification of this bird as a Little Stint certain, in my view.
As I have studied the photos supplied by David in greater detail, I have become 100% certain that he recorded two Little Stints at Cek Jawa, and I recommend that this record be accepted by the Records Committee.