140 
with flocks of other species, though when disturbed separates from them 
to rejoin the company later. 
243. Dunlin (Including Red-backed Sandpiper), black-heart plover. Pelidna 
alpina. L, 8. A small Sandpiper. Spring adult, back extending to crown predominantly 
red; very finely striped across breast, up neck, and on face, with ashy brown on white. 
Throat white. Large black area occupying abdomen. Bill slightly down-curved (Figure 
164). 
In autumn, plumage soft, uniform, light ashy grey all above and suffusing across 
breast; remainder white. Autumn adults usually have a few of the red summer feathers 
on the back. There is a juvenile plumage with black and buffy back and a spotted breast 
of which only traces remain when the birds return to us in the autumn. 
Bill of Red-backed Sandpiper; natural size. 
Distinctions. In spring, the predominantly red back, and the black abdominal patch 
are absolutely distinctive. No other species has so much red on back. The coast form of 
the Purple has a blended dark area on the breast instead of the abdomen that does not 
cut sharply against the white above as it does on this species. The grey autumn plumage 
resembles that of several other species of similar size, but of them only the White-rumped 
and Sanderling ever show the clear, patternless (except for a few black and red-margined 
intrusive feathers), grey back. The former has a white rump, the grey of the latter is 
almost white, and the hind toe is absent. The other evenly grey-backed autumn Sand- 
pipers — Knot, Wandering Tattler, and Surf Bird — are all so much larger that no mistake 
can be made. The moderately long (over 1J inches), slightly decurved bill is generally 
characteristic. 
Field, Marks. In spring, red back, and black abdominal patch contrasting sharply 
with nearly white breast. In autumn, small size, moderately long (longer than head) and 
slightly decurved bill, and patternless light grey coloration above. 
Distribution. Eastern and western hemispheres. In America, across the Arctic, 
migrating down both coasts and through the interior. Common migrant in Manitoba, but 
authenticated records for Alberta and Saskatchewan are few. Not reported from interior 
of British Columbia, but common on the coast. 
SUBSPECIES. The American Dunlin or Red-backed Sandpiper Pelidna alpina 
sakhalina, differs from the European race by its slightly larger size. It extends to the east 
Siberian coast. 
This species frequents sand-bars, mud-flats or tide-meadows. It is 
among the latest Shore Birds to arrive both in spring and autumn. 
246. Semipalmated Sandpiper, black-legged peep. Ereunetes pusillus. L, 
6-30. Plate XVII B. Next to the smallest of our Sandpipers, being only slightly larger 
than the Least (page 139). 
Distinctions. Except on the Pacific coast, to be confused only with the Least Sand- 
piper. Compared with that species, slightly larger. The best distinction is the partial 
webbing of the toes that give the name “Semipalmated” (Figure 165, compare with 163). 
Above, it is a greyer bird than the Least; the breast spotting is clearer and the white 
ground with less overwash. When overwash occurs it is greyish rather than buffy. Young 
birds may have slight buff breast band, but the stripes are almost absent on it. The bill 
is slightly longer and thicker than the Least and the legs black instead of olive green. 
