318 BULLETIN 14 6, UNITED STATES NATIONAL MUSEUM 



I have a set of two eggs in my collection, taken by W. W. Brown, 

 jr., May 2, 1912, on San Jose Island; the nest is described as a de- 

 pression, lined with pebbles, in a crevice on top of a jagged, weather- 

 worn ledge, 40 feet above the surf. There are two sets in the Thayer 

 collection, taken by Mr. Brown near La Paz on March 24 and 26, 

 1909 ; one nest was similarly located to mine : " it was out of reach 

 of the surf, but the spray, no doubt, dampened it in rough weather " ; 

 the nest from which the other set was taken is described as " a depres- 

 sion in the sand." The eggs were laid on the bare ground, there 

 being no lining to the nest whatever. It was 80 feet from the surf. 



Eggs. — The Frazar oyster catcher lays two or three eggs, some- 

 times only one. These are practically indistinguishable from those 

 of the American oyster catcher. The measurements of 27 eggs aver- 

 age 57.1 by 38.8 millimeters; the eggs showing the four extremes 

 measure 60.9 by 37.8, 59.8 by 41.5, 50.7 by 40.8, and 60.7 by 36 

 millimeters. 



Plumages. — The plumages and molts from the downy stage to 

 maturity are apparently the same as in the American oyster catcher. 

 Mr. Bancroft (1927) has published some interesting notes on his 

 observations, which suggest that either there are two color phases in 

 these birds or that they interbreed with black oyster catchers {hach- 

 7nani) and produce hybrids ; I am inclined to accept the latter theory, 

 but quote from Mr. Bancroft's (1927) paper, as follows: 



Ninety per cent of tlie oyster catchers had white bellies, the rest had all their 

 underparts black, with the exception of one, whose belly vv^as streaked black 

 and white. Mr. Chester Lamb wrote me that on Natividad Island there was a 

 much larger percentage of mixed underparts than we found. That there were 

 two phases of one bird instead of two distinct species in the lagoon was appar- 

 ent to anyone watching them. There was only one case I observed of a black 

 bird paired with another black ; all the other blacks had white-bellied mates. 

 The difference between the birds was limited to the abdomens ; place a mixed 

 series in a row with the backs up and one could not tell one bird from another. 

 In their conduct, especially when their nests were threatened, there were no 

 differences at all. I feel perfectly safe in saying there were no black oyster 

 catchers {Haematopus baclimani) present. I have seen too many of them, from 

 Monterey to Sitka, not to know by heart every movement they will make and 

 every note they will utter when one trespasses on their home sites. The actions 

 and the cries, and especially the noise, are more unusual and more uniform 

 than those of any bird with which I am acquainted. They fly customarily in a 

 complete half circle from the rocks on one side to those on the other, the birds 

 keeping near each other and almost always close to the water. The noise is 

 incessant, shrill, continuous, and loud beyond belief. The contrast with the 

 birds in Scammons is striking. There, both the white and the black bellied are 

 almost as silent as plover and try to Viu safety by a prodigious show of in- 

 difference. There is little or no excitement while we tramp around the nesting 

 sites. When the parents find we can not be persuaded to follow them away 

 they take up positions 50 to 100 feet from us and there remain motion- 

 less, usually as long as we are in the neighborhood. There is another great 



