BLACK OYSTER CATCHER 321 



with black spots and blotches, was added the almost perfect assimilation of 

 form to that of the rounded pebbles. 



Eggs. — The black oyster catcher lays two or three eggs, occasion- 

 ally only one and more rarely four. They are very much like the 

 eggs of the American oj^stei" catcher, but perhaps they will average 

 a little more buffy. They are ovate in shape and have a very slight 

 gloss. The ground colors vary from " cream buff " to " olive buff." 

 They are usually quite evenly covered with small spots and scrawls 

 of black or very dark browns, " bister " or " Dresden brown," and 

 various shades of "Quaker drab." The measurements of 44 eggs 

 average 56.2 by 39.5 millimeters ; the eggs showing the four extremes 

 measure 62 by 39.5, 58.1 by 42, 51 by 39.5 and 54.2 by 37.5 millimeters. 



Young. — Nothing seems to be known about the period of incuba- 

 tion or whether both sexes share in it ; both parents are interested in 

 the care of the young and are very solicitous for their welfare. Dr. 

 Joseph Grinnell (1910) writes: 



Dixon observed two half-grown young running about on the beach ; but as 

 soon as the old birds, which were always watching, saw anyone approaching a 

 warning note was uttered, at which the young ones promptly squatted among 

 the rocks wherever they happened to be, even if in the edge of the water. They 

 remained perfectly quiet and blended so nicely with their surroundings that it 

 was difficult to locate them even when they had been previously seen from a 

 distance. The old birds attacked and put to rout any gulls or ravens that 

 approached the vicinity. 



Prof. Harold Heath (1915) says: 



The precocial fledglings very early accompanied their parents on short jour- 

 neys about the cliffs, and within a week after hatching were observed pecking 

 at limpets, although it is highly probable that for several days thereafter they 

 depended on the old birds for the gi'eater part of their food supply. During 

 this time the young resemble diminutive ostriches, with thick-set legs, big feet, 

 and fluffy plumage, which, it may be added, harmonizes to a high degree with 

 the surroundings. Furthermore, they have the same habit of hiding the head 

 when it is not possible to conceal the entire body beneath a stone. 



Pliimhages. — The downy young black oyster catcher is a swarthy 

 little fellow, clothed in short, thick, dark, grizzly down, a color pat- 

 tern well suited for concealment among the dark rocks where it lives. 

 The down of the upper parts is basally sooty black and very dark 

 gray, but the pale buffy tips give the bird its grizzly appearance. 

 There is an indistinct loral and postocular stripe and two broad, 

 more distinct, parallel stripes down the back of brownish black and 

 two blackish areas on the thighs; between the back stripes and on 

 the rump the buff tips produce a transverse barred effect. The under- 

 parts are dull grays, darkest on the throat and breast and lightest on 

 the belly ; the sides are faintly mottled or barred. 



