141 
The Semipalmated is separated from the Western Sandpiper on the west coast with 
even greater difficulty than from the Least. The Semipalmated is smaller than the Western, 
but larger than the Least. The bill is considerably smaller 
(under rather than over 0-95 inch) (Figure 162), the back rarely 
has an appreciable amount of red, and the breast spots in 
comparable plumages are not so sharp and clear cut. In high 
spring plumage, the colour characters are plain, in autumn they 
are rather obscure; general size and size of bill make the best 
differentiation. 
Field Marks. Away from the coast, to be confused only 
with the Least Sandpiper. Larger size, greyer back, and, in 
spring, more sharply-defined breast spotting. Legs black 
instead of olive green. From western by smaller size; in spring, 
by very much greyer back and less sharply-defined breast spots; 
in autumn, size when possible to make direct comparison is the 
best criterion. On the west coast, one of the earliest of the 
migrant Waders to arrive in the autumn. 
Distribution. North and South America. Breeds on Arctic 
coast to mouth of Yukon. Migrates through the interior and on 
both coasts. Common nearly everywhere in migration. Prob- 
ably the commonest and most widely distributed of the Peeps. 
Figure 165 
Foot of Semipalmated 
Sandpiper; 
natural size. 
247. Western Sandpiper, western peep. Ereunetes mauri. L, 6-50. Like the 
Semipalmated Sandpiper but larger, especially in the length of bill. In spring and in most 
young autumn birds, back strongly red, even redder than the Least and with a well- 
defined reddish bar across nape. 
Distinctions. Typical birds are easily recognized by their long bill (over 0-95 inch) 
(Figure 162), large intermixture of red in back and across nape, and the heavy, sharp 
spotting of breast. Many specimens, however, are not so easily recognized and it is only 
by the aggregate of various characteristics that they can be determined. 
Field Marks. The largest “Peep,” with bill longer than head, very red on back and 
with shai ply-defined spotting on breast. Any one of these characters may be obscure or 
absent. 
Distribution. North and South America. Breeds on northwest Alaskan coast. Of 
peculiar winter distribution. Occurs from California south and also on the Atlantic coast 
m migration as far north as New York, but as yet there are no records from the continental 
interior between and it is not known how they reach the extreme east ; from the far west coast. 
248. Sanderling. Crocethia leucophaea. L, 8. In spring — 
upperparts, including crown, dark brown, variegated with much 
light rusty ochre, or white, or both. Below, white. Throat, 
neck, and upper breast overwashed with variable amounts of 
reddish-ochre spotted with brown. The details of these colour- 
ings are exceedingly variable. The back may show enough of 
the various colours to make it either generally greyish, 
ochraceous, or rusty, and the coloured and spotted throat may 
be nearly immaculate white. The autumn bird is similar with- 
out much buffy or any reddish or ochraceous tint, it is pure 
white below and in front, and often predominantly grey to light 
ashy above. 
Distinctions. From traces to strong washes of rusty on 
neck and around head in the spring, and the general whiteness 
in autumn. The Sanderling may be told from all other Sand- 
pipers by having three toes instead of four (Figure 166). 
Field Marks. Rufous suffusion about the head in some 
spring birds, general contrasting black and white appearance 
on the wing. The line of white along the bases of flight feathers 
is probably the best field mark common to all plumages. The 
pure white breast in autumn is also characteristic. 
Distribution. Breeds on the islands of the Arctic west to Alaska. A common migrant 
on sandy shores throughout Canada except interior of British Columbia where it is rather 
rare. 
Figure 166 
Foot of Sanderling; 
natural size. 
