500 GAME BIBBS OF CALIFORNIA 



in walking is said to be clumsy, perhaps because of the disproportion 

 between their large bodies and their short legs. But at times they 

 are quite nimble. When foraging on a beach, they advance and 

 retreat with agility before the wash of the waves. The strong bill, 

 wedge-shaped towards the tip, seems admirably adapted to their 

 peculiar method of gaining a livelihood ; and it is put to good use in 

 prying loose from the rocks the various kinds of mollusks which form 

 their staple diet. They seem to enjoy standing on a partially sub- 

 merged ledge of rock with their feet now and then awash, and are 

 wont on such occasions to call back and forth to one another with 

 loud curlew-like cries of a quality which carries well above the noise 

 of the surf. 



The nesting season of the Black Oyster-catcher in California 

 extends from the middle of May to the latter part of June (Willett, 

 1912a, p. 42 h The earliest nesting is that recorded by Willett (1909, 

 p. 187) who took a set of half-incubated eggs near Port Harford, 

 San Luis Obispo County, May 14, 1909, and also three other sets on 

 May 15, 16, and 17, and the latest date is for a set of two fresh eggs 

 found at Seal Rocks, near Cypress Point, Monterey County, June 21, 

 1902 (Grinnell, MS). The recorded instances of nesting range geo- 

 graphically from San Clemente Island (Cooper, 1870&, p. 79), to 

 Seal Rocks, Monterey County (Grinnell, MS), but the species may be 

 expected to nest in suitable localities at many other points farther to 

 the northward. 



Black Oyster-catchers nest on the same rocky islets that they 

 inhabit at other times of the year. Sometimes they nest in the near 

 neighborhood of such birds as Gulls and Cormorants; again they are 

 the sole inhabitants of these wave-swept spots. The birds seem to 

 prefer the smallest detached rocks to the larger islands, probably 

 because of the greater measure of protection afforded by the former. 

 The nests are placed on the bare rocks, sometimes but a short dis- 

 tance above the high-water mark, or again at a considerable distance 

 above the reach of the waves. The nest itself is merely a slight 

 natural depression in the rock surface, or in whatever thin covering 

 of soil there may be. The only lining provided is a number of small 

 pebbles or bits of rock or shell which may be either smooth and 

 rounded, or angular and sharp ; no vegetation whatever is included as 

 lining material. 



A set of eggs number either two or three, although Cooper {in 

 Baird, Brewer and Ridgway, 1884, I, p. 117) states that he found 

 a nest containing four on Santa Barbara Island, June 3, 1863. The 

 eggs are ovate, and measure 2.08 to 2.38 by 1.45 to 1.58. The ground- 

 color varies from grayish olive to greenish, with superficial spots and 

 blotches of black and dark brown, and deeper-lying ones of lavender 

 (Willett, 1909, p. 187). 



