It now seems to be generally recognized that this Lower California oyster catcher is a subspecies of palliatus, although William Brewster (1902) originally described it as a full species and named it in honor of the veteran collector, M. Abbott Frazar. Dr. Robert Cushman Murphy (1925) has recently reviewed this group, in which he has designated six subspecies of palliatus, inhabiting various parts of North and South America. To frazari he assigns the following limited range:

Pacific and Gulf coasts of Lower California and adjacent parts of Mexico, including the islands; formerly northward in Ventura County, Calif.; southward along the west coast of Mexico to Tepic and Jalisco, and at least occasionally to Guerrero.

Ridgway lists specimens from Sihutanejo and Acapulco, Guerrero. Contrary to former opinion, however, this race is principally confined to the zone of generally arid shores centering about the peninsula and gulf of Lower California. Its range approaches or meets that of H. p. palliatus on the more tropical coast farther south, probably at a point not far from the Isthmus of Tehuantepec.

He says of the characters of this race:

The subspecific characters of frazari, which include darker coloration of the brown upper parts than in palliatus, heavy mottling on the breast along the junction of white and black plumage, longer wing and tail (?), and smaller bill and feet, are given fully by Ridgway. The latter makes no mention, however, of the practical elimination of the white blotching of the primaries, a character which this oyster catcher shares with other western races. In most specimens the white spots are wholly lacking, but a few show obsolescent white or mottled markings of the conventional pattern on the eighth or ninth from the outermost quill. It is interesting to note that the mottling of the breast, which is so strongly typical of this race, appears to be carried by a genetic factor deeply rooted in the species as a whole. Scarcely any large series of H. p. palliatus, indeed, lacks one or more birds of this type. In its maximum expression, however, when the whole breast, sides, flanks, and under tail coverts are heavily blotched, the character is peculiar to frazari.

W. Leon Dawson (1923) says, in explanation of its disappearance from California:

By reason of its conspicuous coloration, as well as its excessive noisiness, the Frazar oyster catcher has suffered a fatal prominence. Its former appearances on the Channel Islands (as far north as Ventura County) were concluded by an early martyrdom, and the species is rare even in its primitive fortresses on Los Coronados Islands.

Nesting.—Being more permanently resident than even its eastern relative, the Frazar oyster catcher has no migrations, except its late summer wanderings, and remains on its breeding range throughout the year. As to the nesting habits of this bird at Scammons Lagoon, Lower California, Griffing Bancroft (1927) writes:

They climb up on the shell banks which are the back stops of the beaches and there build their nests. The shell banks are usually a yard or two above high-water mark; they are flat and quite narrow and often have fingerlike projections of 50 yards or so on the same level, running toward the east. Typically, all these higher flats are composed of nothing but shell, largely unbroken and of a size which may be judged in the accompanying illustration. Sand and small impurities have been garnered by the wind. The oyster catcher likes to build her nest where she has an unobstructed view in all directions, securing to herself the opportunity of slipping off unobtrusively at the approach of an enemy. But she is a stupid bird and is easily satisfied with a makeshift which seems to her to accomplish her purpose but in reality does not do so at all. So on some of the earthen islands we find her nesting on little mounds, from which, it is true, she can see, but to only a matter of a few feet.

In the Gulf of California the favorite site for an oyster catcher is the end of the rather long spits of cobblestones. These are so nearly level that a sitting bird has an unobstructed view for a hundred yards. There she builds a nest of fine hard material—small pebbles and bits of shell. And as she can not have broken the larger stones that were originally on the site she must have removed them. I use the analogy for Scammons. Instead of breaking the shells with her powerful bill she probably pulls them out of the way until she has a flat circle about 10 inches across. This clearing she lines as neatly as tile work, and on them deposits her eggs, one, two, or three. The breeding season seems quite long, as we found both well-developed young and fresh eggs. I have observed parents with their young long after the latter had taken wing, and so feel sure that the oyster catchers raise but one brood a year.

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 depression, lined with pebbles, in a crevice on top of a jagged, weatherworn 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 depression 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, sometimes only one. These are practically indistinguishable from those of the American oyster catcher. The measurements of 27 eggs average 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 (bachmani) 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 the oyster catchers had white bellies, the rest had all their underparts black, with the exception of one, whose belly was 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 apparent 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 bachmani) 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 win safety by a prodigious show of indifference. 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 motionless, usually as long as we are in the neighborhood. There is another great difference between H. bachmani and the black phase in the south. The former is decidedly darker than the latter, especially on the back, whereas true Haematopus frazari from both ends of the Gulf appear to be the same as those in Scammons.

We found and photographed a pair of downy young not over a few days old. These youngsters are obviously of the white and black types, respectively; we have the skins to show that there is no photographic illusion here. So we have very strong evidence that the black and the white phases do mate and do produce fertile offspring and that the young have partaken of the coloring, one of one parent and one of the other. These little birds are not mongrels, though we know from some adults that occasionally there are chicks which do inherit from both parents. Comparison shows that the white-breasted downy does not differ at all, at a cursory glance, from a baby taken on Coronado Island in the Gulf.

Behavior.—The same observer writes:

Scammons Lagoon is a haven for oyster catchers, or appears so to such of us as are accustomed to but an occasional pair scattered along the various islands and rocky projections in the more northerly Pacific Ocean. There are at least two or three hundred oyster catchers fairly evenly distributed over the islands we visited, with an occasional pair or so on favorable mainland strands. When the tides are going down vast stretches of hard flats are exposed and become feeding grounds. The birds pursue the receding water even to the point of wading, and there they hunt the small marine life on which they live. When the tide turns they use the black levels as a lounging place until driven ashore by the sea. They are markedly indolent and slow in movement and, when undisturbed, never appear the least bit busy.

Walter E. Bryant (1890) says:

I found this oyster catcher tolerably common at Magdalena Bay and northward, and on Santa Margarita Island. They were mated in January. They were rather shy, running rapidly on the beach, and if approached, taking wing with loud, clear, whistling notes, and after flying some distance, alighting again at the water’s edge. Their food was chiefly small bivalves found in the gravelly beach.

DISTRIBUTION

Range.—Pacific coast of Mexico and southern California. The Frazar oyster catcher is confined chiefly to Lower California (San Quintin Bay, Cedros Island, Natividad Island, San Roque, Ascuncion Island, Los Coronados Islands, Carmen Island, San Jose Island, La Paz, and Todos Santos); and the mainland coast of Mexico; Sonora (Quotla); Sinaloa (Altata); Nayarit (Maria Madre Island, Maria Cleofas Island, Tres Marias, Isabela Island, and San Blas); and Guerrero (Sihutanejo, and Acapulco). The species is of casual occurrence (formerly more common) on the coast and islands of southern California (San Diego, Santa Barbara Island, San Clemente Island, and Ventura County). Breeding records for California are not satisfactory.

Egg dates.—Lower California: 39 records, March 24 to June 24; 20 records, April 22 to May 13.