birding-aus
On the subject of Snipe ID:
I have only seen Chinese on one trip - in the Darwin area. They seemed
smaller, shorter-billed, more rounded-winged than Japanese, and they behaved
differently, more like other waders. All these differences are subjective,
and might be hard to use in a different setting or by someone without a lot
of experience with both species.
In examining many skins of both species, I found what seems to be a useful
mark which could be used in the field under favourable conditions. In both
species, the lateral uppertail coverts seem to be enlarged compared to the
other tail coverts. These feathers are often visible at the side of the base
of the tail in a bird on the ground. On a Jap Snipe, they are typically
buffy with a white tip and a narrow blackish line inside the white tip and
which follows around parallel to the edge of the feather. The curvature of
the black line looks convex if you look at it from the end of the feather.
On a Chinese Snipe, these feathers are white with blackish crossbars which
are, if anything, concave as viewed from the end of the feather. This
difference is sometimes visible in photos and can be seen with a scope if
you closely watch birds on the ground. I have often done this with Jap
Snipes, and have never see one which showed the Chinese-type pattern there.
However, I want to make it clear that observers should seek to test this
proposition, not to just accept it as true! Also, it seems that Pintail
shows a pattern on the lateral uppertail coverts which is similar to that of
Chinese.
Another feature I noticed on Chinese in flight was that the underparts
appeared to show only a relatively small, well-defined white belly patch,
which was bordered anteriorly by the darker chest markings and at the sides
by heavy dark barring along the flanks. On the many Japs I have watched in
flight, I have never seen this pattern. Instead, the barring on the flanks
is much less conspicuous and also less extensive, so that the white belly
patch seems both more extensive and less well-defined, and it also tends to
break through at the front of the flanks, so the flank barring seems
slightly separated from that of the chest. Again this is something which
needs testing - it might be that it is only of use in certain plumage
states, and it might prove very unreliable in Chinese. I have also not been
able to see any correlates of this feature in birds on the ground - I
suspect that the positioning of the flank feathers is too variable when the
birds aren't flying.
Chris Corben
PO Box 2323
Rohnert Park
CA 94927-2323
USA
707-584-8711
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