224 BULLETIN 142, UNITED STATES NATIONAL MUSEUM 



that completely decorates that part of the egg. These spots are irregular in 

 shape, but are inclined to be elongated with their axis twisting to the right, 

 so that when a series of eggs is viewed looking toward the larger end, the 

 spots produce a clockwise spiral. Some of these spots are more twisted than 

 others, but on a few eggs there are no spiral tendencies at all. The surface 

 spots are quite variable in color, dependent largely on the thickness of the 

 pigment deposited, for where the latter is thin the true color is observable, 

 but when the decoration is liberal, the blot becomes opaque and the color is 

 lost. These spots range from " aviburn " and " raw umber " to " chestnut 

 brown " and " blackish brown." The underlying spots are well hidden by the 

 boldness of the surface markings and inclined to be small and regular and 

 are often more or less numerous. Their shades are delicate, ranging from 

 " pallid gray " to " mouse gray." An occasional egg exhibits scattering in- 

 significant additional markings of deep " blackish brown." 



The measurements of 145 eggs average 36.3 by 25.3 millimeters; 

 the eggs showing the four extremes measure 40.1 by 25.9, 39.2 by 

 26.5, 34 by 25, and 34.5 by 23.5 millimeters. 



Young. — Both sexes incubate and are rather close sitters, as well 

 as devoted and bold in the defense of their young. The period of 

 incubation is probably the same as for the European dunlin, 22 days. 

 John Murdoch (1885) says: 



Both parents share in the work of incubation, though we happened to obtain 

 more males than females with the eggs. The young are pretty generally 

 hatched by the first week in July, and both adults and young keep pretty 

 well out of sight till the 1st of August, when they begin to show about the 

 lagoons and occasionally about the beach, many of the young birds still downy 

 about the head. The autumn flight of young birds appears about the middle 

 of August, associating with the young A. maculata and M. griseus scolopaceus, 

 in good-sized flocks, particularly about the pools on the high tundra below Cape 

 Smythe. They continue plenty in these localities, sometimes appearing along 

 the beach, for about a week, when the greater part of them depart, leaving 

 only a few stragglers that stay till the first few days of September. 



Plumages. — The downy young red-backed is much paler and more 

 buffy than that of the least sandpiper. The crown, back, wings, 

 and thighs are variegated with brownish black, " ochraceous tawny " 

 and " hazel," except at the base of the down on the back, there is no 

 rich, deep brown; the above parts are quite thickly sprinkled, 

 especially on the back, with minute, round spots, terminal tufts of 

 pale buff ; a distinct stripe of these nearly encircles the posterior half 

 of the crown. The black of the crown extends nearly to the bill and 

 there is a black loral stripe ; the rest of the head and a band across 

 the lower throat are "warm buff." The rest of the under parts are 

 white. The nape is a grizzly mixture of dull buff and dusky. 



The juvenal plumage, as seen in Alaska in August, is strikingly 

 handsome and quite distinctive. The feathers of the crown are 

 dusky, edged with " ochraceous tawny " ; the sides of the head and 

 nape are " drab-gray," streaked with dusky ; the feathers of the 

 back are black, broadly edged Avith three colors in different areas, 



