Part 5

_Fall._--Dr. Walkinshaw (1938) says that "the majority of the Prothonotaries leave our rivers [Michigan] by the second or third of July. One may canoe some years a good many miles during the latter part of July or the early part of August without finding a single Prothonotary, whereas in other years many groups can be found. The majority evidently are early migrants. Very few remain until late August or early September, the latest date being September 9, 1934, at Battle Creek."

The 1931 A. O. U. Check-List states that this warbler apparently crosses the Gulf of Mexico in migration "and is not found in Mexico north of Campeche," but probably some migration is along the coast of Texas and Mexico, as suggested by George G. Williams (1945).

Dr. Chapman (1907) says: "The route of the Prothonotary Warbler in its fall migration is interesting; the breeding birds of the Middle Atlantic States apparently pass southwest to northwestern Florida and then take a seven-hundred-mile flight directly across the Gulf of Mexico to southern Yucatan, instead of crossing to Cuba and thence to Yucatan."

Alexander F. Skutch writes to me: "Unrecorded from Guatemala, the prothonotary warbler is a rare bird of passage and very rare winter resident in the more southerly portions of Central America. When Carriker published his list of Costa Rican birds in 1910, he had a few records from the highlands--apparently of migrating birds--and from the Pacific lowlands, but none from Caribbean lowlands. But on March 4, 1934, I found it not uncommon at Puerto Limón, where I saw one among the royal palms in Vargas Park, and several among the shrubbery about the outlying cottages, all within a hundred yards of the Caribbean Sea. It has been recorded a number of times from the Canal Zone, but it is not common there. It is almost always seen in the vicinity of water."

_Winter._--Apparently the main winter range is in Colombia and perhaps Venezuela. Referring to Magdalena, Colombia, P. J. Darlington, Jr. (1931), writes: "The Prothonotary Warbler swarms during the winter in the mangroves at Sevillano and in the fresh swamps at Cienaga. It was seen also in bushes on the sea beach at Donjaca September 15, and along the Rio Frio River in the edge of the foothills, where it was especially common in February. The birds usually occur near water, but numbers were noted again and again in yellow-flowering, acacia-like trees on the border of stump land and dry forest, far from water."

DISTRIBUTION

_Range._--Eastern United States to northwestern South America.

_Breeding range._--The prothonotary warbler breeds =north= to southeastern Minnesota (Cambridge, Lake Pekin, and La Crescent); central Wisconsin (New London and Shiocton); southern Michigan (Hesperia, Lansing, and Ann Arbor); northern Ohio (Toledo and Cleveland); extreme southern Ontario (Rondeau); western New York (Buffalo and Oak Orchard); northern West Virginia (Parkersburg); central Maryland (Seneca and Bowie); and southern Delaware (Gumboro). =East= to southern Delaware (Gumboro); eastern Virginia (Dyke, near Alexandria, and Dismal Swamp); and the Atlantic coast to central Florida (Lake Gentry and Padgett Creek). =South= to central Florida (Padgett Creek and possibly Puntarossa); the Gulf coast to southeastern Texas (Cove, Houston, and Bloomington). =West= to central Texas (Bloomington, Fort Worth, and Gainesville); central Oklahoma (Norman and Oklahoma City); eastern Kansas (Emporia and Manhattan); northwestern Iowa (Lake Okoboji); and southeastern Minnesota (Rochester, Red Wing, and Cambridge).

The prothonotary warbler has been recorded as casual or accidental =west= to southeastern Nebraska (Powell and Lincoln); southeastern South Dakota (Yankton and Sioux Falls); and central Minnesota (Brainerd). =North= to southern Ontario (London and Hamilton); central New York (Ithaca); Massachusetts (Northampton, Amherst, and Concord); New Hampshire (Concord); and Maine (Matinicus Island and Calais).

_Winter range._--The winter home of the prothonotary warbler is in Central America and northwestern South America where it has been found =north= to northwestern Costa Rica (Bolson); Nicaragua (Escondido River). =East= to northwestern Venezuela (Mérida and Encontrados); and western Colombia (San José de Cucuta and Villavieja). =South= to southwestern Colombia (Villavieja); and northwestern Ecuador (Esmeraldas). =West= to northwestern Ecuador (Esmeraldas); western Colombia (Antioquia); western Panamá (Paracote and David); and Costa Rica (Puntarenas and Bolson). It has been reported to occur in winter in Campeche and on Cozumel Island, Mexico, and casually or accidentally in Cuba (Habana), Jamaica, and St. Croix, Virgin Islands.

_Migration._--The probable route of the prothonotary warbler between its summer and winter homes is across the Gulf of Mexico, from the Yucatan peninsula where it occurs in both spring and fall migration. The casual or accidental occurrences of this warbler in Cuba (Habana); Jamaica; and St. Croix, Virgin Islands, are in migration.

Late dates of spring departure are: Colombia--Villavieja, February 5. Panamá; Canal Zone--Barro Colorado, March 10. Nicaragua--Edén, March 23. Quintana Roo--Cozumel, April 6. Cuba--Habana, April 4.

Early dates of spring arrival are: Yucatán--Mérida, March 28. Jamaica--Black River, February 28. Cuba--Habana, March 31. Florida--Pensacola, March 18. Alabama--Booth, April 4. Georgia--Fitzgerald, March 21. South Carolina--Yemassee, March 27. North Carolina--Greenville, April 6. Virginia--Suffolk, April 10. Mississippi--Gulfport, March 18. Louisiana--Morgan City, March 10. Texas--Cove, March 28. Arkansas--Huttig, March 31. Missouri--St. Louis, April 17. Kentucky--Bowling Green, April 5. Illinois--Murphysboro, April 17. Ohio--Berlin Center, April 18. Michigan--Grand Rapids, May 3. Iowa--Iowa City, April 26. Wisconsin--Madison, May 2. Minnesota--Red Wing, May 7. Oklahoma--Tulsa, April 2. Kansas--Manhattan, April 26. Nebraska--Blue Springs, April 30.

Late dates of fall departure are: Nebraska--Watson, September 1. Oklahoma--Oklahoma City, September 14. Texas--Kemah, September 11. Wisconsin--Racine, September 22. Iowa--Sioux City, August 31. Michigan--Three Rivers, September 13. Ohio--Columbus, October 5. Illinois--Oak Park, October 17. Kentucky--Lexington, October 6. Tennessee--Elizabethton, October 19. Louisiana--Monroe, October 8. Mississippi--Deer Island, September 27. North Carolina--Raleigh, August 26. South Carolina--Charleston, September 17. Georgia--Atlanta, October 8. Yucatán--Chichén-Itzá, October 18.

Early dates of fall arrival are: Florida--Fort Myers, August 8. Yucatán--Chichén-Itzá, October 7. Honduras--Tela, September 8. Nicaragua--Río Escondido, September 2. Costa Rica--Bonilla, August 28. Panamá--Obaldia, September 15. Colombia--Gaira, September 11.

_Banding records._--Banding provides a hint as to the life-span of the prothonotary warbler. One banded as an immature on June 16, 1940, in Convis township, Calhoun County, Mich., was color banded when it returned to the same place in 1942. Subsequently it was identified by the colored band on May 14, 1944, and May 10, 1945.

_Casual records._--The prothonotary warbler was reported at Nassau, Bahamas, on August 29, 1898. It has been twice reported at Bermuda: one shot from a flock in the fall of 1874, and another specimen collected in November 1903. A single bird was observed at Mammoth Hot Springs, Yellowstone Park, Wyo., on September 10, 1931. There are two records for Arizona. On May 1, 1884, a specimen was taken near Tucson at an altitude of 2,300 feet, the highest record of the species in the United States. Another specimen was taken September 8, 1924, at Cave Creek, 4 miles northeast of Paradise in the Chiricahua Mountains.

_Egg dates._ Florida: 8 records, April 18 to May 9; 5 records, April 28 to 30.

Illinois: 79 records, May 6 to June 21; 46 records, May 20 to June 4, indicating the height of the season.

Iowa: 56 records, May 15 to June 26; 36 records, May 27 to June 6 (Harris).

LYMNOTHLYPIS SWAINSONII (Audubon)

SWAINSON'S WARBLER

CONTRIBUTED BY EDWARD VON SIEBOLD DINGLE

PLATES 7-9

HABITS

"The history of our knowledge of Swainson's Warbler," write Brooks and Legg (1942), "is a curious one, falling into definite periods." This bird was discovered in the spring of 1832 by the Rev. John Bachman "near the banks of the Edisto River, South Carolina." His discovery of the bird is described as follows: "I was first attracted by the novelty of its notes, four or five in number, repeated at intervals of five or six minutes apart. These notes were loud, clear, and more like a whistle than a song. They resembled the sounds of some extraordinary ventriloquist in such a degree, that I supposed the bird much farther from me than it really was; for after some trouble caused by these fictitious notes, I perceived it near to me and soon shot it" (Audubon, 1841). Dr. Bachman took five specimens; then, up to the spring of 1884, Swainson's warbler remained almost a lost species, for according to Brewster (1885a) there is no record of more than eight or nine birds being collected. Wayne, through collections and field work near Charleston, opened a productive 25-year period in the history of _swainsonii_, in which many valuable contributions were made by various observers. From 1910 to 1930 the name _swainsonii_ was practically absent from the pages of current ornithological literature.

Brewster (1885a) has given us the best description of the bird's haunts in the low country:

The particular kind of swamp to which he is most partial is known in local parlance as a "pine-land gall." It is usually a depression in the otherwise level surface, down which winds a brook, in places flowing swiftly between well-defined banks, in others divided into several sluggish channels or spreading about in stagnant pools, margined by a dense growth of cane, and covered with lily leaves or other aquatic vegetation. Its course through the open pine-lands is sharply marked by a belt of hardwood trees nourished to grand proportions by the rich soil and abundant moisture. Beneath, crumbling logs cumber the ground, while an undergrowth of dogwood (_Cornus florida_), sassafras, viburnum, etc., is interlaced and made well-nigh impenetrable by a network of grapevines and greenbriar. These belts--river bottoms they are in miniature--rarely exceed a few rods in width; they may extend miles in a nearly straight line.

The writer has had a long acquaintance with Swainson's warbler in the low country of Carolina. Except during September (fall migration) the birds were almost never seen out of sight of substantial growths of cane, even when the nests were built in bushes, low trees, or vines. This has been the experience of practically all observers and, as Brooks and Legg (1942) remark, "an idée fixe among ornithologists" existed; the familiar description of habitat by Brewster (1885a) became a dictum: "Briefly, four things seem indispensible to his existence, viz., water, tangled thickets, patches of cane, and a rank growth of semi-aquatic plants."

Hence, the ornithological world received a surprise to learn that _swainsonii_ was a summer resident and breeder in different localities of high altitude in the Appalachian Chain. Although several observers have found the bird nesting beyond the limits of the Coastal Plain, even in Piedmont territory, as La Prade (1922) did at 1,050 feet above sea level, it was E. A. Williams (1935) who first detected it in a truly mountainous terrain. During two successive summers he found birds near Tryon, N. C., "in open woods."

Loomis (1887) was quite prophetic when, in recording a Swainson's warbler from Chester, S. C., "in the heart of the Piedmont Region, one hundred and fifty miles from the coast," he wrote: "It awakens the mind to the possibility of an Up-Country habitat, yet awaiting discovery, where the true centre of abundance will finally be located."

The efforts of Brooks and Legg (1942) have shown Swainson's warbler to be a locally common summer resident in south-central West Virginia up to an elevation of 2,000 feet above sea level; no positive evidence of breeding has been found, but it undoubtedly does breed. In Tennessee, Wetmore (1939) has found the bird in mountainous country at 3,000 feet.

The question naturally arises, Did Swainson's warbler always inhabit higher altitudes, or is this a recent extension of range and partial change of habitat? The answer will probably never be found; but study of changing conditions in its low country habitat for the past several decades may throw light on this interesting problem. Within the writer's experience the canebrake areas have long been exposed to forest fires, timber cutting, overgrazing, drainage, and the construction of a hydroelectric project, as a result of which thousands of acres of timbered swampland are now under water.

_Spring._--The birds that winter in Jamaica enter the United States through Florida, but it is probable that those from Yucatán make a direct flight across the Gulf to the delta of the Mississippi. The earliest recorded spring arrival in the United States was on March 22, 1890, on the lower Suwanee River. The same year the species was taken at the Tortugas, March 25 to April 5 (Chapman, 1907). The earliest arrival near New Orleans, was March 30, 1905 (Kopman, 1915). Meanley (MS.) records it from central Georgia on March 31, 1944. Swainson's warbler reaches the vicinity of Charleston, S. C, during the first week of April, the earliest being the fifth of that month.

_Nesting._--Nests are built in bushes, canes, masses of vines, and briers; 10 feet seems to be the maximum height from the ground, while some nests have been found as low as 2 feet. The average elevation would be around 3 feet. As many nests are built over dry ground as over water. The nest is quite bulky and loosely constructed; a typical one in situ looks like a bunch of leaves lodged in a bush or cane, as the stems point upward. The outer walls of the nest are composed of various leaves such as oak, gum, maple, tupelo, and cane; the inner walls are usually of cane, while the lining is of pine needles, black fiber of moss _Tillandsia_, cypress leaves, rootlets, or grass stems. Sometimes horsehair is also present.

[AUTHOR'S NOTE: A few more notes on the nesting of Swainson's warbler may well be added to the above general statements. Brewster's (1885b) nests, taken by Wayne in the low country of South Carolina, are evidently typical for that region. All four of these nests were in canes. Wayne (1886) says that the nests "are generally built in canes," but he has also found them "in small bushes, and in one instance in a climbing vine, by the side of a large public road." Brewster (1885b) gives the measurements of two of his nests; the smallest of the four measures--

externally 3.50 in diameter by 3.00 in depth; internally 1.50 in diameter by 1.50 in depth; the greatest thickness of the rim or outer wall being 1.00. * * * The nest June 27 is very much larger, in fact quite the largest specimen that I have seen, measuring externally 5.00 in diameter by 6.00 in depth; internally 1.50 in diameter by 1.25 in depth; with the rim in places 1.75 thick. It is shaped like an inverted cone, the apex extending down nearly to the point of junction of the numerous fascicled stems which surround and support its sides. Its total bulk fully equals the average nest of our Crow Blackbird, while it is not nearly as finished a specimen of bird architecture. Indeed it would be difficult to imagine anything ruder than its outer walls,--composed of mud-soaked leaves of the sweet gum, water oak, holly, and cane, thrown together into a loose mass, bristling with rough stems, and wholly devoid of symmetry or regularity of outline. The interior, however, lined with pine needles, moss fibre, black rootlets, and a little horse-hair, is not less smooth and rounded than in the other specimens.

Troup D. Perry (1887), with his friend George Noble, found no less than 24 nests near Savannah, Ga., in 1887; some of these were in gall or myrtle bushes and one was in a saw palmetto 2-1/2 feet high. S. A. Grimes has sent us a photograph of a nest on the broad leaf of a saw palmetto (pl. 7). Albert J. Kirn (1918) says of the nesting sites of Swainson's warbler in Oklahoma: "A well shaded clump of trees in the woods, such a place as would suggest itself for a Wood Thrush, yet not exactly so, with considerable 'buck brush' undergrowth, but no grass or weeds is selected for a nesting site. In the top of this 'buck brush' usually about two feet high the nest is built; about half of the nests found were close to the river bank--the Little Caney River. All but two were built in the brushy undergrowth. These two were fastened to briers and slender brush and were higher up, 3.5 and 4 feet."

F. M. Jones wrote to Brooks and Legg (1942) of a nest found in southwestern Virginia: "This nest was in a very dense growth of rhododendron bushes close to a stream of water where the sunlight never penetrated. It was 5 ft. 6 in. up, built in the forks of a slender beech limb which grew across the top of a rhododendron bush (_R. maximum_) and partly supported by the top of the rhododendron. * * * The outside of the nest measured 7 in. wide by 5 in. deep and the inside 2 in. wide by 1-13/16 in. deep."

It is evident, from the above and other similar accounts that, at higher elevations northward and westward, Swainson's warbler nests in bushes and vines where there are no canes to be found.]

_Eggs._--Swainson's warbler usually lays three eggs; sets of four are rare and of five very rare. Although there are records of nests containing two incubated eggs or two young birds, these probably represent incomplete sets or cases where an egg or a nestling has been destroyed.

Eggs are quite globular, the two ends sometimes scarcely distinguishable; the shell is thick and has a distinct polish; the ground color is white with a bluish tinge; however, a set of three eggs in the writer's collection had a faint greenish tinge, while several observers describe sets of pale pink or buffy white.

Rarely, spotted eggs are found. Wayne (1910) says: "Spotted eggs are, however, very rare and I have found only four or five nests containing them." The only spotted egg the writer has found is in the set referred to above; of these, two are immaculate, while the third is "faintly though distinctly speckled around the larger end with reddish brown" (Dingle, 1926).

Brewster (1885b) describes a set collected by the late Arthur T. Wayne: "One is perfectly plain; another * * * has two or three minute specks which may be genuine shell markings; while the third is unmistakably spotted and blotched with pale lilac. Over most of the surface these markings are fine, faint, and sparsely distributed, but about the larger end they become coarser, thicker, and deeper colored, forming a well-defined ring or wreath."

Burleigh (1923) writes: "Unlike all the descriptions I had read, and the few eggs I had seen, these were light pink in ground color and dotted distinctly over the entire surface with light brown spots, this almost forming a wreath at the larger end of one egg." These eggs were found near Augusta, Ga., and the parent was secured.

Wayne (1910) was of the opinion that two broods are raised in a season.

[AUTHOR'S NOTE: The measurements of 50 eggs average 19.5 by 15.0 millimeters; the eggs showing the four extremes measure =21.6= by 14.2, 20.8 by =16.0=, =18.0= by 14.1, and 19.5 by =13.5= millimeters (Harris).]

_Plumages._--[AUTHOR'S NOTE: Ridgway (1902) describes the juvenal plumage of Swainson's warbler as follows: "Head, neck, back, rump, upper tail-coverts, chest, sides, and flanks plain brown (varying from broccoli to bister); rest of under parts whitish or dull pale yellowish, more or less clouded with brown; middle and greater wing-coverts indistinctly tipped with cinnamon-brown; otherwise like adults, but no trace of lighter superciliary nor darker postocular stripes." Specimens that I have seen in this plumage are more nearly "cinnamon-brown" than the colors named above on the back and wing coverts, and the latter show very little evidence of cinnamon tips.]

The postjuvenal molt, which evidently includes only the contour plumage and the wing coverts, occurs early in the summer; I have seen young birds beginning to acquire the first winter plumage as early as June 12, and others that had nearly completed the molt on July 20; these birds were not yet fully grown. Wayne (1910) writes: "I have taken young birds which were as large as the adults and which were acquiring their autumnal plumage as early as June 2, but it must be borne in mind that the season in which these young were taken (1906) was exceptionally advanced."

Brewster (1885a) describes the young bird in its fall plumage as follows: "Entire upper parts rich olive strongly tinged with reddish-brown, the crown scarcely deeper-colored than the back, the wings a trifle redder; loral stripe blackish; superciliary stripe tinged with yellow; under parts strongly yellowish, otherwise like the adult."

The nuptial plumage is apparently assumed by wear and fading, the reddish-brown and yellowish colors becoming much duller. There are no specimens available of either young or adult birds that indicate a prenuptial molt.

The postnuptial molt seems to occur mainly in August, but perhaps earlier, and is evidently complete; I have seen birds in full, fresh autumn plumage as early as August 28. This fresh plumage is similar to the spring plumage, but the crown and back are nearly uniform brown, the crown is darker than in spring, the back is browner than in spring, and the breast and flanks are more or less clouded with grayish.

_Food._--Howell (1924) says that "four stomachs of this bird from Alabama contained remains of caterpillars, spiders, and Hymenoptera (ants, bees, etc.)."

Brewster (1885a) considered the principal food to be small coleopterous insects, "as well as some small green worms that are found on water plants, such as the pond lily (_Nymphaea odorata_) and the Nelumbium (_Cyamus flavicomus_).

_Behavior._--Swainson's warbler is an unsuspicious bird and can be easily observed in its haunts where the vegetation is not too dense and tangled and the tree canopy overhead partially open. The neutral color of the bird is often apt to conceal him in the shadowy undergrowth. Singing males usually remain on the same perch during their periods of song, apparently disinclined to move. He often sings from the ground during insect hunting; Meanley (MS.) says: "It was so wrapped up in its song as to be absolutely unconcerned; it sang at my very feet with its head thrown back, its beak pointing perpendicularly toward the sky, pouring forth its resounding melody in the best of warbler fashion."

The female is a close sitter, and the observer has usually to touch her before she leaves the nest. Grimes (1936) writes: "This bird would not leave her eggs until _pushed_ off, and when I held my hand over the nest she straddled my fingers in trying to get back onto it. * * * When I did drive her away from the nest she fluttered along on the ground in the manner of a crippled bird, her actions manifestly intended to induce me to follow. This bird certainly was not badly frightened, for within a few minutes she was back on her nest, accepting deerflies from my fingers and swallowing them with apparent relish."

Brewster (1885a) gives an admirable portrayal: