JRED-BACKED SANDPIPER 385 



Ordinarily this species is rather tame and will allow close approach, 

 but if flocks are shot at even a lew times they become wary. When 

 frightened, or when taking wing in changing to a new location, the 

 birds bunch together into a compact flock and fly rapidly, sometimes 

 in a direct line at low elevation, sometimes erratically, up and down 

 and zigzag. In the lattei- instance they partake somewhat of the 

 nature of Snipe. As many as 500 have, by estimate, been noted in a 

 single flock. The close-flocking habit of this and most other shore birds 

 is probably of advantage to them in detecting and escaping from 

 enemies under primitive conditions ; but the modern hunter with his 

 seatter-gun is able to make large "pot-shots," and there are records 

 of over fifty Red-backs being killed by the discharge of the two barrels 

 of one double-barreled gun into a single flock (Porbusli, 1912. p. 283). 



The breeding area of the Red-backed Sandpipers visiting Cali- 

 fornia lies probably along the western coast of Alaska, where the 

 species is known to summer in abundance. The species thus presents 

 an interesting peculiarity as regards its breeding range. There are 

 two distinct areas, corresponding with the divided winter distribution. 

 One is along the coast of Alaska from the mouth of the Yukon to 

 Point Barrow and along the Arctic coast of Siberia, where our Cali- 

 fornian birds are thought to nest. The birds found along the eastern 

 coast of North America probably breed in northern Ungava and in 

 the region of Melville Island. Between Melville Island and Point 

 Barrow the species is exceedingly scarce or altogether absent. 



The nesting season in Alaska extends through the month of June, 

 eggs having been taken at the mouth of the Yukon as early as the 

 6th of that month (Cooke, 1910, p. 44), and as late as the 3rd of July 

 (Nelson, 1887, p. 110), while fresh eggs have been taken near Cape 

 Prince of Wales on June 27 and 28 (Grinnell, 1900, p. 24). 



The nest is usually located on a slight elevation of the tundra, 

 although as a rule not far from water. It consists of a depression in 

 the top of a grassy or mossy hummock, lined with a few grass blades ; 

 in some cases the surrounding vegetation practically hides the nest. 



The eggs number three or four, are notably pear-shaped, and 

 measure in inches, 1.36 to 1.60 by 0.93 to 1.10, and average 1.46 by 1.01 

 (21 eggs from Alaska). The ground color is pale olive, buffy, or drab, 

 with light and dark yellowish brow^n, superficial spots and a few 

 lavender or pale gray deep-lying ones. The spots are usually 

 elongated, measuring on the average, perhaps 0.06 by 0.12 inches, 

 and have a distinctly spiral trend, especially about the larger end. 

 Here they are often so numerous as to form a dark cap. These eggs, 

 by their combination of pale olive ground color with light brown 

 sr)irally placed markings, together with their size, can readily be dis- 

 tinguished from those of any other species of shore bird occurring in 

 western America. 



