A striking resident of coastal areas, the pied plumage and large red bill of the American Oystercatcher make it distinctive, though its foraging habits are just as unusual. American Oystercatchers specialize in finding and opening marine clams.
Both mammals and birds occasionally prey on oystercatchers, and in very rare instances an anchored clam may clamp down on an oystercatcher’s bill and hold it so tightly that the bird drowns with the rising tide. A maximum lifespan of 17 years has been documented in the wild.
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Description of the American Oystercatcher
The American Oystercatcher is large and tall, with a heavy, reddish bill, a black head and neck, brownish back, and white underparts. It has a reddish eye ring.
Same as male.
Seasonal change in appearance
Immatures are similar to adults but have darker bills and mottled upperparts.
Beaches and tidal flats.
Mussels, clams, and worms.
Forages by walking, sometimes in shallow water.
American Oystercatchers breed along the Atlantic, Gulf, and southern Pacific Coasts and are resident in most areas. Populations generally stable.
Bent Life History
Visit the Bent Life History for extensive additional information on the American Oystercatcher.
The shape of a bird’s wing is often an indication of its habits and behavior. Fast flying birds have long, pointed wings. Soaring birds have long, broad wings. Different songbirds will have a slightly different wing shape. Some species look so much alike (Empidonax flycatchers) that scientists sometimes use the length of specific feathers to confirm a species’ identification.
– wing: Female, North Carolina, Jan.
Wing images from the University of Puget Sound, Slater Museum of Natural History
American Oystercatchers usually forage deliberately, turning alternately left and right to search for food.
American Oystercatchers sometimes sleep while standing up, and they tuck their bill into their feathers.
American Oystercatchers give a loud peep call that is often repeated.
The Black Oystercatcher is an all-black version of the American Oystercatcher. Ranges overlap in southern California and northern Baja California.
The American Oystercatcher’s nest is in shallow scrape in the sand, sometimes lined with pebbles.
Color: Buffy-grayish with darker markings.
Incubation and fledging:
– Young hatch at about 24-28 days.
– Young fledge (leave the nest) shortly after hatching, but associate with the adults for some time.
Bent Life History of the American Oystercatcher
Published by the Smithsonian Institution between the 1920s and the 1950s, the Bent life history series of monographs provide an often colorful description of the birds of North America. Arthur Cleveland Bent was the lead author for the series. The Bent series is a great resource and often includes quotes from early American Ornithologists, including Audubon, Townsend, Wilson, Sutton and many others.
Bent Life History for the American Oystercatcher – the common name and sub-species reflect the nomenclature in use at the time the description was written.
HAEMATOPUS PALLIATUS FALLLIATUS (Temminck)
The usual impression that one gets of this large and showy wader is a fleeting glimpse of a big, black and white bird disappearing in the distance over the hot, shimmering sands of our southern beaches. It is one of the shyest and wildest of our shore birds, ever on the alert to escape from danger; I have never shot one and seldom have had half a chance to do so. Even during the breeding season when its anxiety for its eggs or young prompts it to be less wary, it flies around the intruder in wide circles, well beyond gun range, yelling its loud notes of protest. It was evidently about as shy even in the days of Audubon and Wilson, for both mentioned its wariness. It was much commoner in those days, of course, and enjoyed a much wider distribution. Audubon (1840) records it at Portland, Me., and as breeding on the south coast of the Labrador Peninsula; it seems as if he must be mistaken about the latter locality, although it is interesting to note that the European oyster catcher breeds as far north as Russian Lapland.
The oyster catcher prefers the same broad, sandy beaches as the Wilson plover and the least tern select for their breeding grounds; and at other reasons it frequents similar resorts with all the little sand plovers and beach birds. The small plovers are protectively colored, but the oyster catcher is not only big, but is most conspicuously colored. Perhaps it needs no protection against the ordinary foes of the little fellows; and evidently its wits are sufficient protection against larger enemies. But in spite of the fact that it is well able to take care of itself, its range has been greatly restricted and its numbers very much reduced during the past 50 years. It formerly bred abundantly on Cobb Island, Virginia, but when we were there in 1907 we saw very few and found no nests or young.
H. H. Bailey (1913) says:
This large, showy bird fell an easy mark to the spring gunners, breeding as it did during the height of the spring migration of ‘ beach birds,” from May 10 to 25. Nesting among the sand dunes or flat beaches hack from the ocean, over which the spring gunners tramped daily, these birds were right in the line of travel, so to speak, and were either killed or their nests broken up.
Recent records from South Carolina, where we found it common in 1915, seem to indicate that it is becoming rarer even there. And during the winter of 1924 and 1925, spent on the west coast of Florida, I saw only one.
Nesting: While visiting Arthur T. Wayne on the coast of South Carolina, we found three nests of three eggs each of the oyster catcher on May 22 and 23, 1915. The first two nests were on the broad, sandy beaches of Bull’s Island among numerous scattered bits of shells. The other was on Vessel Reef in Bull’s Bay, a low, fiat, sand reef, with small areas of marsh grass in which willets were nesting. The oyster catchers’ nests were all on the higher parts of the dry, flat, sand beaches, well above high-water mark; they were mere holIows in the sand, entirely without lining, on little mounds of same or elevations, where the birds could have a good outlook; usually a regular pathway of footprints in the sand led up to the nest. Ihe birds were never seen on or near the nests, but were flying about in the distance making a great outcry. The nests were easily found by following the tracks and looking for the little elevations. Several pairs of Wilson plover were nesting near them.
W. J. Erichsen (1921) “found a single egg deposited in a depression on top of a wall of oyster shells on Raccoon Key,” but an unusually high tide washed the egg away. He also found a set of three eggs “in a slight depression on top of a bank of oyster shells which had been thrown up by the surf”; and he says that “where nesting sites of this character can be found, this species always selects them.”
Oyster catchers’ nests are usually not near together, but M. H. Burroughs has sent me some notes on some nests he found in Glynn County, Ga., that are an exception to the rule. A set of four eggs, two fresh and two partially incubated, was “on a slight mound, the nest having a few broken bits of shells in it and nearly entirely surrounded with a rim of broken bits of shells, evidently raked up by the birds.” Six feet away, under a log” which had both ends resting on mounds of sand,” was a set of two. There were two other nests, each about 150 feet away in different directions.
George B. Sennett (1879) found a nest on Padre Island, Tex., which was quite different he describes it as follows:
The nest was situated on dry mud a rod or so from the water, and was simply a slight depression, of the size of a small tea plate, lined with shells and pieces of shells; none of them were larger than an inch in diameter, and most much smaller. They were chiefly small oyster shells, and were placed more on the sides than at the bottom of the nest. No particle of grass or anything else but shells composed the nest. What was strange to me was that on the island where I found It not a shell or piece of one could be seen, and these must have been brought by the bird Itself from the adjacent shell Islands or oyster beds. This was the only nest found on the Island.
Walter J. Hoxie (1887) claims to have seen an oyster catcher remove the eggs from a nest he was watching. Both birds were standing near the nest, when “one flew off to a distance of about 100 yards.” He then observed:
After looking carefully about for a few minutes, he gave a call, and his mate rose from her nest and joined him. They seemed to be making a lot of fuss out there, kicking up the sand, squatting down, and cackling like mad. In a few minutes, though, they seemed to get over this excitement and one bird came flying back and settled on the eggs. Now she begnn to act strangely, wiggling round and squatting down again, and I began to think she was going to lay another egg, when off she went and joined her mate who welcomed her coming with the most extravagant cries and gestures. But she sat down quite still and demure. I was about to rise and look for my third egg when I saw her coming back. Again she went through the same operation and her second welcome was, If possible, more exuberant than the first. Then all was (inlet; one bird sat on the sand and the other stood silently by her, and though I waited some time longer they showed no sign of returning again to their eggs, and I could only conclude that they had seen me watching them and would not come back until I went away. So I arose from my uncomfortable position and went to pick up the eggs, when to my surprise the little hollow in the said was empty. While I was watching the curious antics of the female she had lifted the eggs between her legs and carried them off. So without givlig time for her to repeat the offense I hurried to her new quarters and secured them successfully.
Eggs: The oyster catcher lays two or three eggs, more often the latter I believe, and very rarely four. They are ovate to elongate ovate in shape and have only a very slight gloss. The ground color is usually “cartridge buff,” sometimes it is “pale olive buff” and rarely “deep (‘live buff” or dull “chamois.” They are irregularly and rather sparingly marked with spots and small blotches, occasionally a few scrawls of black, brownish black, or very dark browns, “mummy brown ” or ” bister,” and underlying spots in various shades of ” Quaker drab” or “mouse gray.” The measurements of 56 eggs averag3 55.7 by 38.7 millimeters; the eggs showing the four extremes measure 62 by 38.9, 57.2 by 42.2, 51.8 by 39.9, and 52 by 33.5 millimeter~.
Young: The period of incubation for the European species is from 21 to 24 days, and both sexes share in this duty, though it is mostly performed by the female. We have no data on this subject for the American species, but probably it is not much different. When the temperature is just right the eggs may be left exposed to the sun, bul. at night or when it is too hot or too cold they are covered by the incubating bird, whose judgment is reliable in such matters.
The young are able to run soon after they are hatched, and when they become s.:rong on their legs they can run so fast that it is very difficult tc catch them. At a note of warning from their watchful parents, thy squat in the sand, or against some convenient object, and remain perfectly still, their protective coloring making them almost invisible. Both parents show their anxiety by flying around, usually at a safe distance, and yelling their loud notes of protest. Herbert K. Job (1905) once hunted thoroughly over a barren strip of sand, where he knew there was a young oyster catcher, without success; he was about to give it up and go away, when he saw a little wisp of driftwsed at the water’s edge on a strip of bare wet sand; and beside it the young bird was lying, flat on the sand and absolately motionless. It did not move while he was photographing it, but as soon as lb was touched off it ran as fast as it could go.
Plumages: iIn the downy young oyster catcher the upper parts are grizzled with pale buff and dusky; the down is dusky basally and heavily tipped with “pinkish buff”; the crown is mostly pale buff and the hind neck nnd throat are mostly dusky; the back appears more mottled end has two quite distinct, broad stripes of brownish black; there h sometimes a similar broad stripe on the nape; a narrow black line runs from the bill, through the eye and to the nape; a broad black band extends from behind the wing to the tail; below this and the dusky throat the under parts are white. When very young, the bill is decidedly hooked at the extreme tips of both mandibles. In a young bird, about one-quarter grown, the primaries are bursting their sheaths and the white greater coverts are growing; the juvenal plumage is appearing on the back, scapulars and lesser wing coverts; these new feathers are “sepia,” broadly tipped with “cinnamon “; the crown is “bister,” faintly tipped with “cinnamon”; the white plumage is coming in on the breast.
In full juvenal plumage, when the young bird is nearly fully grown, these colors are somewhat paler; the feathers of the back, scapulars and wing coverts are “Saccardo’s umber,” tipped with “clay color” or “cinnamon-buff “; the crown, sides of the head, and upper chest are dark “bister,” tipped with “cinnamon-huff”; the chin and throat are mottled with sepia and huffy; the upper tail coverts are white, tipped with huffy; the tail is dark “bister,” tipped with “cinnamon-huff”; and the under parts are white. By the end of July the huffy tips on the mantle have nearly disappeared by wear. Early in September the post-juvenal molt begins; this involves the body plumage, hut not all the scapulars and wing coverts and not the tail.
The first winter plumage is like the adult, the head and neck being “fuscous” or ” Chaetura black” and the mantle “deep mouse gray.” Young birds can be distinguished hy a. somewhat slenderer bill and by the retained and worn juvenal wing coverts, scapulars, and tail feathers. At the first prenuptial molt they become fully adult.
Adults have a partial prenuptial molt in late winter and early spring, involving the body plumage and most of the scapulars and wing coverts, and a complete postnuptial molt in late summer and fall.
Food: Audubon (1840) says of the feeding habits of the oyster catcher:
I have seen it probe the sand to the full length of its bill, knock off ilinpets from the rocks on the coast of Labrador, using its wenpon sideways and insinuating It between the rock and the shell like a chisel, seize the bodies of gaping oysters on what are called in the Southern States and the Floridas “raccoon oyster beds,” and at other times take up a “razor handle” or solen, and lash It against the sands until the shell was broken and the contents swallowed. Now and then they seem to suck the sea urchins, driving in the mouth, and introducing their bill by the aperture, without breaking the shell; again they are seen wading up to their bodies from one place to another, seizing on thrimps and other crustacen, and even swimming for a few yards, should this he necessary to enable them to remove from one bank to another without flying. Small crabs, fiddlers, and sea ivorins are also caught by it, the shells of which, in a broken state, I have found in its gizzard in greater or less quantity. Frequently, while on wet sea beaches, it pats the sand to force out the insects; and In one Inst moe I saw an individual run from the water to the dry sand with a small floundur in its bill, which It afterwards devoured.
Wilson (1832) says that they probe in the sand “with their long, wedgelike bi Us in search of small shellfish. This appears evident on examining the hard sands where they usually resort, which are found thickl; perforated with oblong holes, 2 to 3 inches in depth.” lie seemed to doubt the reports of their eating oysters, but C. J. Maynard (W96) writes:
When the or tgoing tide left the tops of the oyster bars exposed, they would come flying sils ntly In, at first singly, then in pairs, while groups of a few would follow, until, al. last, they would come in flocks of a dozen or more. They would alight among the oysters and when the bivalves gaped open, as Is their habit when the water first leaves them, the birds would thrust in the point of their hard, fiat bills, divide the ligament with which the shells are fastened together, then, having the helpless inhabitant at their mercy, would at once devour it. They were not long in making a meal, for specimens which I shot after they had been feeding a short time were so crammed that by simply holding a bird by the legs and shaking it gently the oysters would fall from its mouth.
Behavior: Oyster catchers are strong, swift fliers and at times are graceful and elegant in their movements. They are striking birds in flight, displaying to good advantage their conspicuous patterns of black and white and their bright red bills. Their movements on the ground are equally graceful as they walk sedately along the beach or wade out into the water until the waves lap their breasts. They can swim perfectly well and can even dive readily if necessary. Audubon (1E 40) describes their flight evolutions as follows:
Now wheeling with wonderful impetuosity they pass within a hundred yards of you, and suddenly checking their flight return, not low over the water as before, but high in the air. Again, they form their ranks in a broad front, and, again, as if suddenly alarmed by the report of a distant gun, they close pollmell, and dip towards the sands or the waters. Shoot one at such a moment and you may expect to kill another; but as this Is done, the wary birds, as if suddenly become aware of your intentions, form themselves into a straggling line, and before a minute has elapsed, far beyond reach, and fading out of the view, are the remaining oyster catchers.
Voice: The loud, striking notes of protest, heard as the oyster catcher flies around the intruder on its breeding grounds, are quite unlike any other bird notes; they sound like wlteep, wheep, wiuceop, and are both vehement and penetrating. John T. Nichols says in his notes: “The oyster catcher has a creeking note, crik, cHic, cHic, etc., used when the bird takes wing. A more striking cry, cle-ar, suggests the Ilight calls of the willet and the black-bellied plover.”
Field ~ large wader, with black head and dark upper parts, with a big white patch in its long, pointed, black wings and with white under parts, can be nothing but an oyster catcher. No other bird ol strong, steady flight can be mistaken for it, One is seldom near Enough to recognize its long, red bill.
Winter: The oyster catcher is resident throughout most of its range, but it retires in winter from the northern portion of its breeding range. Arthur T. Wayne (1910) says:
In the winter the oyster catcher is very gregarious and it is not unusual to see flocks containing from 20 to 75 individuals. The majority of these birds are undoubtedly migrants from points to the northward of South Carolina and not the resident breeding birds, which apparently go together in pairs or small flocks of from 4 to 6 individuals.
Range: Atlantic and Gulf coasts of the United States, Central and South America. The American oyster catcher has been subdivided into several races the exact range of which it is not now possible to define. This should be borne in mind in considering the following outline, which undoubtedly includes the ranges of H. p. durnfordi, H. p. prattii, and H. p. pitamaaj (Murphy). Generally speaking, jnattii is assumed to be confined to the Bahama Islands, durnfordi the South Atlantic coast of South America, and the Pacific coast of South America.
The species is not migratory in a strict sense, although the examples breeding at the north and south extremes of the range probably retire short distances toward the Equator when forced to do so by climatic conditions.
The range may be outlined as follows: North to Texas (Brownsville, Padre Island, Corpus Christi, and Galveston); Louisiana (Isla a Pitre); probably rarely Alabama (Petit Bois Island); and formerly southern New Jersey (Great Egg Harbor). East to formerly southern New Jersey (Great Egg Harbor, and probably Seven-mile Beach); probably rarely Maryland (Ocean City); Virginia (Hog Island, Cobb Island, and Smiths Island); North Carolina (Cape Hatteras, Ocracoke Thlet, and mouth of Cape Fear River); South Carolina (Waverly Mills, Raccoon Key, Bulls Bay, Sullivan Island, and Frogmore); Georgia (Savannah, St. Simon Island, and Cumberland); Florida (St. Johns River, Charlotte Harbor, and probably Cape Sable); the Bahama Islands (Abaco, Andros, Long, Mariguana, and Inagna Islands); probably Porto Rico (Desecheo Island); Venezuela (Aruba, Curacao, and Cumana); Brazil (Santa Catherina, Cajetuba, Rio de Janeiro, Sapetiba Bay, and Iguape); Uruguay (La Paloma and Montevideo); and Argentina (Lavalle, Cape San Antonio, Mar Chiquita, and mouth of Chubut River). South to Argentina (mouth of Chubut River) and Chile (Ancud). West to Chile (Ancud, Algarrobo, Santiago, Chanaral, and Atacama); Peru (San Nicolas Bay, Independencia Bay, Pisco Bay, Chilca, and San Lorenzo); Ecuador (Gulf of Guayaquil and Santa Elena); Panama (Pearl Island); Yucatan (Cozumel Island and Merida); and Texas (Brownsville).
Casual records: The American oyster-catcher has on a few occasions been di:cected north of its normal range. Among these occurrences are: New York, a specimen in New York Harbor, May 28, 1877, one about March 9, 1880, at Ponquogue, and one at Greenport, June 2,1882; Massachusetts, two in August, 1899, at Chatham, one in April, 1885, at Monomoy Island, two seen September 10, 1924, at Eastharn, a pair taken in 1837, at Marshfield, and one in Boston harbor, killed prior to 1814; Maine, reported by Audubon as occurring at Portland but this record is considered doubtful; New Brunswick, a specimen has been reported upon the authority of Boardman (Baird, Brewer, and Ridgway, 1884) as taken at Grand Manan. This last is considered unsatisfactory as being indefinite, while Audubon’s statement that it bred in Labrador is probably an error.
Egg dates: Virginia: 37 records, April 20 to July 9; 19 records, May 21 to June 19. South Carolina and Georgia: 25 records, March 27 to June 25; 13 records, May 5 to 23. Texas: 8 records, March 29 to May 5.
FRAZAR OYSTER CATCHER
HAEMATOPUS PALLIATUS FRAZARI (Brewster)
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, itihabiting 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 pallietus, heavy mottling on the breast along the junction of white and black plumage, longer wing and tail (‘1), and smaller bill and feet, are given fully by Ridgway. The latter makes no mention, however, of the practical elimination of the white blotch ing 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. pallietus, 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 hack 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, hut 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 fiat 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 t.he 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 showir~g 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 brtchmani) 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. bachme’ni and the black phase in the south. The former is decidedly darker than the latter, especially on the back, whereas true Haemato pus frozen 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 do~ 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 hut 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.
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 (Quotl&); Sinaloa (Altata); Nayarit (Maria Madre Island, Maria Cleof as Island, Tres Marias, Isabela Island, and San Bias); 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: 89 records, March 24 to June 24; 20 records, April 22 to May 13.