The Nashville has at least two main perch-songs, and a flight-song, all subject to a good deal of variation. It belongs decidedly among the full-voiced Warblers.* * *Its commoner perch-song consists of a string of six or eight or more, lively, rapid notes, suddenly congested into a pleasant, rolling twitter, lower in key than the first part of the song, and about half as long. In the other perch-song, the notes of what correspond to the rolling twitter are separate and richer, and the second part of the song is longer and more noticeable than the first, whose notes are few and slurred, while the whole is more languidly delivered.The differences are hard to describe intelligibly; but in reality they are pronounced and constant. The flight-song, a fairly common performance in late summer, is sung from the height of five to forty feet above the (usually low) tree-tops. It is like the commoner perch-songs, but more hurried, and slightly elaborated, often with a fewchippingsadded, at both ends. Among the Nashville’scalls a very small, drychip, and a more metallic, louderchip, somewhat Water-Thrush-like, are noteworthy. It alsochipperslike a young Warbler or a Black-throated Green.
The Nashville has at least two main perch-songs, and a flight-song, all subject to a good deal of variation. It belongs decidedly among the full-voiced Warblers.* * *Its commoner perch-song consists of a string of six or eight or more, lively, rapid notes, suddenly congested into a pleasant, rolling twitter, lower in key than the first part of the song, and about half as long. In the other perch-song, the notes of what correspond to the rolling twitter are separate and richer, and the second part of the song is longer and more noticeable than the first, whose notes are few and slurred, while the whole is more languidly delivered.
The differences are hard to describe intelligibly; but in reality they are pronounced and constant. The flight-song, a fairly common performance in late summer, is sung from the height of five to forty feet above the (usually low) tree-tops. It is like the commoner perch-songs, but more hurried, and slightly elaborated, often with a fewchippingsadded, at both ends. Among the Nashville’scalls a very small, drychip, and a more metallic, louderchip, somewhat Water-Thrush-like, are noteworthy. It alsochipperslike a young Warbler or a Black-throated Green.
Miss Stanwood (1910a) writes:
One common song sounds like‘tsin, ‘tsin, ‘tsee, anothersweeten, sweeten, ‘tsee, a third,sillup, sillup, sillup, ‘tsee-e-e-e-e-e. At other times the bird sings but part of the song assweeten, sweet; orsweeten, ‘tsee; orsweeta, sweeta, ‘tsee; or recombines them differently assweeten, sweeten, sweeten, ‘tsee-e-e-e-e-e.* * *The song is loud, constant, and heard all over the locality, coming principally from the gray birches, but also from the maples, poplars, and evergreens. The bird sings from the tree-tops, but likewise from the middle branches, and I have seen it singing on the ground and just a few inches above it. My last record of its song in 1908 was made the 17th day of July, the first, May the 14th. Between these dates it sang well-nigh incessantly.
One common song sounds like‘tsin, ‘tsin, ‘tsee, anothersweeten, sweeten, ‘tsee, a third,sillup, sillup, sillup, ‘tsee-e-e-e-e-e. At other times the bird sings but part of the song assweeten, sweet; orsweeten, ‘tsee; orsweeta, sweeta, ‘tsee; or recombines them differently assweeten, sweeten, sweeten, ‘tsee-e-e-e-e-e.* * *
The song is loud, constant, and heard all over the locality, coming principally from the gray birches, but also from the maples, poplars, and evergreens. The bird sings from the tree-tops, but likewise from the middle branches, and I have seen it singing on the ground and just a few inches above it. My last record of its song in 1908 was made the 17th day of July, the first, May the 14th. Between these dates it sang well-nigh incessantly.
Knight (1908) says that, while the female is building the nest, “the male bird perches in a nearby sapling and sings leisurely 'pea-cie-pea-cie-hit-i-hit-i-hit.'” Wilson (1832) thought that the “notes very much resembled the breaking of small dry twigs, or the striking of small pebbles of different sizes smartly against each other for six or seven times, and loud enough to be heard at the distance of thirty or forty yards.” Rev. J. H. Langille (1884) writes: “The song of the Nashville Warbler is a composition, the first half of which is as nearly as possible like the thin but penetrating notes of the Black-and-white Creeping Warbler, while the last half is like the twitter of the Chipping Sparrow.” He writes it in syllables as “ke-tsee-ke-tsee-ke-tsee-chipe-ee-chip-ee-chip-ee-chip.”
The song has been said to resemble that of the chestnut-sided warbler, but the two are really quite distinct; the song of the latter does not end in a trill or in chipperings. It does, however, more closely resemble the song of the Tennessee warbler. Dr. Roberts (1936) heard the two singing at the same time and noted this difference: “The Nashville’s song is an utterance of rather greater volume than that of the Tennessee and differs, also, in the fact that it has a short, rapidly weakening trill or slide, following a rather long and deliberate prelude of four or five notes; while the Tennessee has a brief prelude with a long finishing trill, increasing in loudness and intensity to an abrupt ending.”
Aretas A. Saunders contributes the following study of the song: "The territory song of the Nashville warbler is in two parts, the first a series of 2-note phrases, and the second a series of rapid notes, commonly lower in pitch and just twice as fast as the notes of the first part;pa tipa tipa tipa tipa tititititititit. In 26 of my 29 records the second part of the song is lower than the first. In the other three it is higher. "The pitch of songs varies from G‴ to F sharp‴′, or five and a half tones. Single songs rarely vary more than one and ahalf or two tones. They are from 12⁄5to 2 seconds in length. The quality is rather musical, and some individuals have almost as sweet a tone as the yellow warbler. In my experience field students often confuse the songs of these two species.
“The nesting song may be heard commonly on the breeding grounds. I have several records from the Adirondacks. This song is in three or four parts, each part of three or four notes, and a little lower in pitch than the preceeding part. Two-note phrases are not commonly heard in the nesting song.”
Francis H. Allen’s rendering of the song is not very different from the first one of Mr. Saunders', though he noted some variation, and mentions in his notes an aberrant song, which “doubled the common song, which in this case had a first part consisting of only a single phrase, thus;chip-ee-(trill)chip-ee-(trill).”
Field marks.—The gray head, white eye ring, olive-green back, bright yellow under parts, and the absence of wing bars, with no white in the tail, are the distinguishing marks of the eastern Nashville warbler. The Connecticut warbler has a white eye ring but it has a gray throat, whereas the Nashville is bright yellow from chin to abdomen. The chestnut crown patch is not very conspicuous in the male and is less so, or entirely lacking, in the female; the female is duller yellow below and browner above than the male.
Enemies.—Like other ground-nesting birds, this warbler has the usual four-footed enemies to contend with, but its nest is quite well hidden. Perhaps its worst bird enemy is the cowbird, although Friedmann (1934) listed it as an uncommon victim of this parasite and had only six records of it, the nests containing from one to two eggs of the cowbird.
Fall.—As soon as the molting season is over and the young birds are freshly clad in their winter dress the migration begins in Massachusetts. This takes place in August, and the last stragglers may be seen passing through in early October.
In Ohio, according to Mr. Trautman (1940), the first migrants are seen about the first of September, the peak of the migration coming during the latter half of that month when from 10 to 100 could be found in a day, and after the 10th of October only an occasional bird remains. He writes: “As with many other transient warblers the southward migration of the Nashville Warbler covered a greater period of time than did the spring movement, which usually lasted less than 30 days, whereas the fall movement generally extended more than 45 days.* * *In spring the species frequented the upper half of large trees and was more numerous in tall trees of woodlands than it was in smaller groups or rows of tall trees. In fall the species tended to inhabit the middle section of large trees, and it also resorted to the taller bushes and saplings, especially the larger hawthorn trees.”
The fall migration route is apparently a reversal of the spring route southwestward into Mexico and Central America where it spends the winter.
Winter.—The Nashville warbler is evidently very common in winter in certain parts of Mexico, for Dr. C. William Beebe (1905) says: “At times there were twenty and thirty in sight at once near our camp in the Colima lowlands.” These may have been the western race.
DISTRIBUTION
Range.—Southern Canada to Guatemala.
Breeding range.—The eastern Nashville and the western Nashville (formerly the Calaveras) warblers breednorthto southern British Columbia (Tahsis Canal and Beaver Creek, Vancouver Island; Pemberton, Lillooet, and Revelstoke); northern Idaho (Clark Fork); northwestern Montana (Fortine); east-central Saskatchewan (Cumberland House); southern Manitoba (Duck Mountain, Lake St. Martin, and Hillside Beach); central Ontario (Casummit Lake, Lake Nipigon, and Lake Abitibi); and southern Quebec (Lake Baskatong, Quebec, Kamouraska, Mingan, and Natashquan River).Eastto southeastern Quebec (Natashquan River and the Magdalen Islands); and Nova Scotia (Baddeck, Halifax, and Barrington).Southto Nova Scotia (Barrington); Maine (Ellsworth and Bath); northeastern Massachusetts (Haverhill and Beverly); southern Connecticut (Norwich); northern New Jersey (Moe and Beaufort Mountain); northeastern Pennsylvania (Dingman’s Ferry, Mount Riga, and Highland Falls); northern West Virginia (Stony River Dam, Canaan Mountain, and Cranesville Swamp); northeastern Ohio (Pymatuming Lake); southern Michigan (Ann Arbor); northeastern Illinois (Deerfield); southern Wisconsin (Lake Koshkonong); central Minnesota (Onamia and Detroit Lakes); reported to breed in northeastern Nebraska but no specific records; northwestern South Dakota (Cave Hills); northern Idaho (Falcon); northwestern Oregon (Powder River Mountains, probably); probably western Nevada (Lake Tahoe); and south-central California (Greenhorn Mountains).Westto central and western California (Greenhorn Mountains, Paicines, and Yreka); western Oregon (Pinehurst, Gold Hill, Depoe Bay, and Portland); western Washington (Mount Adams, Tacoma, and Blaine); and southwestern British Columbia (Friendly Cove and Tahsis Canal).
There are several records of the occurrence of this species in spring migration in southern Saskatchewan (Regina, East End, and Maple Creek); and in fall at Lake Kimawan, Alberta, west of Lesser Slave Lake. These records imply the existence of a breeding range north of any yet discovered.
Winter range.—The Nashville warbler and races are found in winternorthto central Durango (Chacala); western Nuevo León (Monterrey) and southern Texas (Somerset and Matagorda County).Eastto southern Texas (Matagorda County, Rio Hondo, and Brownsville); eastern Puebla (Metlatoyuca); western Veracruz (Jalapa); Chiapas (Chicharras); and central Guatemala (Barillos, Panajachel, and San Lucas).Southto Guatemala.Westto western Guatemala (San Lucas and Sacapulas); Oaxaca (Tehuantepec); Guerrero (Acapulco); Colima (Manzanillo); and Durango (Durango and Chacla).
The Nashville warbler has been recorded as wintering occasionally in southern Florida, but in view of the extreme rarity of the species in southeastern United States it seems best to consider the record hypothetical until specimens are collected.
Like other species that winter regularly in the Tropics, the Nashville warbler can resist low temperatures as long as food is available. Evidence of this is seen in the daily presence of one in a garden in New York City from December 16, 1918, to January 9, 1919 (perhaps longer). Another was noted almost daily from January 1 to March 1, 1938, at a feeding table in Arlington, Va. The latter bird was caught and brought to the U. S. Biological Survey for confirmation of the identification, and was banded. On January 31, 1890, a specimen was picked up in Swampscott, Massachusetts, that had apparently been killed by a shrike about two weeks before.
The ranges as outlined apply to the entire species which includes two geographic races; the eastern Nashville warbler (V. r. ruficapilla) breeds from eastern Saskatchewan and Nebraska eastward; and the western Nashville warbler (V. r. ridgwayi) breeds west of the Rocky Mountains.
Migration.—Some early dates of spring arrival are: West Virginia—French Creek, April 23. District of Columbia—Washington, April 20. Pennsylvania—Beaver, April 25. New York—Canandaigua, April 25. Massachusetts—Taunton, April 24. Vermont—Rutland, April 27. Maine—Presque Isle, May 2. Quebec—Kamouraska, May 2. New Brunswick—Scotch Lake, May 8. Mississippi—Rosedale, April 26. Tennessee—Memphis, April 16. Kentucky—Bardstown, April 28. Indiana—Indianapolis, April 24. Ohio—Oberlin, April 19. Michigan—Ann Arbor, April 25. Ontario—Toronto, April 29. Texas—San Antonio, March 27. Arkansas—Delight, April 14. Missouri—St. Louis, April 21. Iowa—Davenport, April 26. Illinois—Chicago, April 25. Wisconsin—Madison, April 25. Minnesota—Red Wing, April 29. Manitoba—Winnipeg, May 2. Arizona—Tucson, April 6. Montana—Missoula, April 25. Idaho—Coeur d’Alene, April 29. California—Buena Park, March 3. Oregon—Prospect,April 20. Washington—Tacoma, April 23. British Columbia—Okanagan Landing, April 21.
Late dates of spring departure are: West Virginia—Wheeling, May 24. District of Columbia—Washington, May 20. Pennsylvania—Jeffersonville, May 20. Mississippi—Rosedale, May 6. Tennessee—Nashville, May 19. Kentucky—Bowling Green, May 19. Indiana—Richmond, June 1. Texas—Ingram, May 10. Arkansas—Monticello, May 9. Missouri—Columbia, May 28. Iowa—Grinnell, June 2. Illinois—Rockford, May 30. Kansas—Lake Quivira, May 21. Nebraska—Red Cloud, May 24. South Dakota—June 1. Arizona—Otero Canyon, Baboquivari Mountains, April 29. California—Cabezon, May 7.
Late dates of fall departure are: British Columbia—Okanagan Landing, September 13. Washington—Port Chehalis, October 11. California—Los Angeles, October 8. Idaho—Bayview, September 12. Montana—Bozeman, September 12. Arizona—Fort Verde, September 28. Manitoba—Shoal Lake, September 26. North Dakota—Fargo, October 15. South Dakota—Mellette, October 4. Nebraska—Blue Springs, October 1. Kansas—Lawrence, October 8. Minnesota—St. Paul, October 25. Wisconsin—Racine, October 6; Madison, November 1. Iowa—Marshalltown, October 14. Missouri—Columbia, October 19. Arkansas—Winslow, October 14. Texas—Cove, November 15. Ontario—Ottawa, October 7. Michigan—Sault Ste. Marie, October 7. Illinois—Springfield, October 2. Ohio—Toledo, October 29. Kentucky—Lexington, October 16. Tennessee—Memphis, October 3. Mississippi—Deer Island, October 16. Quebec—Hatley, October 18. Maine—Portland, October 13. New Hampshire, Center Ossipee, October 23. Massachusetts—Danvers, October 12. New York—New York, October 17. Pennsylvania—Philadelphia, October 17. District of Columbia—Washington, October 14. West Virginia—Bluefield, October 19.
Early dates of fall arrival are: California—Los Angeles, August 9. Arizona—Patagonia, August 8. North Dakota—Rice Lake, August 18. South Dakota—Yankton, August 2. Kansas—Lake Quivira, August 31. Iowa—Iowa City, August 18. Missouri—Montier, August 8. Arkansas—Winslow, September 8. Texas—Rockport, September 1. Illinois—Glen Ellyn, August 16. Indiana—Bloomington, August 26. Ohio—Cleveland, August 2. Kentucky—Versailles, August 13. Tennessee—Marysville, September 1. Massachusetts—Martha’s Vineyard, August 17. New York—Rhinebeck, August 13. Pennsylvania—Pittsburgh, August 28. District of Columbia—Washington, September 5. West Virginia—French Creek, September 7.
The Nashville warbler is a rare species in the lower Mississippi Valley; there are only three records for Louisiana; and it is almost unknown in the Atlantic States south of the Chesapeake Bay.
Casual records.—Four specimens have been collected in Greenland: One at Godthaab, about 1835; two at Fiskenaes, October 10, 1823, and August 31, 1840; and one marked “West Greenland,” between 1890 and 1899. The three latter were all immature birds. A specimen was collected in Bermuda on September 16, 1907.
Egg dates.—Maine: 27 records, May 8 to August 7; 15 records, May 27 to June 14, indicating the height of the season.
Minnesota: 11 records, May 7 to June 15.
Quebec: 32 records, May 28 to July 4; 18 records, June 19 to 29.
California: 23 records, May 17 to July 30; 12 records, May 21 to June 5 (Harris).
VERMIVORA RUFICAPILLA RIDGWAYI van Rossem
WESTERN NASHVILLE WARBLER
HABITS
This western form of our well-known eastern Nashville warbler, often called the Calaveras warbler, was discovered by Robert Ridgway in the East Humboldt Mountains, Nev., on September 6, 1868, and given the subspecific namegutturalis. He (1902) describes it as similar to the eastern bird, “but olive-green of rump and upper tail-coverts brighter, more yellowish, yellow of under parts brighter, lower abdomen more extensively whitish, and greater wing-coverts lighter, more yellowish olive-green.” He gives as its range: “Western United States, breeding on high mountains, from the Sierra Nevada (Calaveras Co., California) to British Columbia (Vernon, Nelson, Okanogan district, etc.), eastward to eastern Oregon (Fort Klamath), northern Idaho (Fort Sherman), etc.; southward during migration to extremity of Lower California, and over western and northern Mexico, and southeastward to Texas (San Antonio; Tom Green County; Concho County).” The 1931 A. O. U. Check-List says that this form winters “in Mexico south to Puebla, Oaxaca, Guerrero, Jalisco, and Colima.”
Dr. Walter K. Fisher wrote to Dr. Chapman (1907): “The Calaveras Warbler is a characteristic denizen of the chaparral and is found on both slopes of the Sierra Nevadas about as far south as Mt. Whitney. It frequents the belts of the yellow, sugar, and Jeffrey pines, and ranges up into the red fir zone. During the height of the nesting season one may see them flitting about among thickets of manzanita, wild cherry, huckleberry, oak and buck brush, almost always in song; and while the female is assiduously hunting among the dense cover ofbushes, the male is often singing in a pine or fir, far above mundane cares.* * *I have observed this Warbler at lower altitudes on the west slope among small black oaks, in company with Hermit Warblers.”
Dr. Wilfred H. Osgood (1896) first saw it in the Sierras at 3,500 feet elevation, but more commonly at 3,700 feet. “At 5,000 feet we found them most common, and from 7,000 to 9,000 feet they gradually disappeared, apparently going as high up as the black oak, in which trees they were generally seen, skipping about in search of insects.”
Grinnell and Storer (1924) say: “The Calaveras Warbler is common during the summer months in the black oaks and maples along each side of the Yosemite Valley and in similar situations elsewhere on the western flank of the Sierra Nevada. Among all the warblers to be seen in the Yosemite Valley during the summer months the present species is the only one which does not forage and nest in the same niche. The Calaveras seeks its food and does its singing well up in trees, but places its nest immediately upon the ground.”
C. W. and J. H. Bowles (1906) write of its haunts in Washington:
Like the hermit warbler, a bird of the higher altitudes in the mountains of California, the Calaveras warbler, on reaching the cooler climate of the northwest, is to be found as a rule only on the driest prairies. Here the birds frequent the scattered clumps of young oaks and fir trees that have reached a height of some three or four feet, and which border the large tracts of dense fir timber. It is a noteworthy fact that, while these birds are not often to be found more than a hundred yards outside of the forests, they are seldom or never seen inside of the dividing line where the heavy timber meets the prairie. Also they do not encroach upon the hillside territory of the lutescent warbler, which bird in turn does not appear on the prairies but confines itself to the brush-covered uplands.
Nesting.—Dr. Osgood (1896) found three nests of the western Nashville, or Calaveras, warbler near Fyffe in the Sierras; two of these were concealed under dead leaves, one of which was partially concealed by a little sprig of cedar at the foot of a cedar stump, and the other was under a little tuft of “mountain misery”; the third was in a thick patch of “mountain misery” and was “well embedded among the roots of this little shrub, and shaded by its thick leaves.”
In the Yosemite Valley, Grinnell and Storer (1924) found a nest in what must be an unusual situation:
The location was only about 75 feet from the much traveled south road on the Valley floor and at the base of the talus pile of huge boulders. The nest was in the face of one of the larger of these boulders, partly in a diagonal fissure. It was on the north side of the rock and so never received any direct rays of sunlight. The whole face of the boulder was covered densely with yellow-green moss which in places was overlaid by olive-gray lichens. The nest was 43 inches from the base of the rock and about 60 inches from the top. Another nest was found in a hollow of the ground at the base of an azalea bush, near an old roadalong the hillside. The creek itself was about 50 feet distant. This nest was 3 inches across the outside and about 2 inches high, the cavity being 11⁄4inches deep. Strips of bark of the incense cedar, plant fibers, and horsehair comprised the building material.
The Bowles brothers (1906) say that the nests are very much like those of the eastern Nashville warbler, as taken by them in Massachusetts. In Washington, “the site chosen is usually at the base of a very young oak, or fir, tho on one occasion we found one built under some blackberry vines at the base of a large fir stub. The nests are sunk well into the ground or moss, and are so well concealed as to defy discovery unless one flushes the bird.”
Eggs.—The eggs of the western Nashville warbler are practically indistinguishable from those of the eastern form. The measurements of 40 eggs average 15.3 by 12.2 millimeters; the eggs showing the four extremes measure16.6by13.2,14.3by 11.9, and 16.0 by11.5millimeters (Harris).
We have no information on the incubation of the eggs or care of the young. The changes in plumage parallel those of the eastern bird. Very little seems to be known about the exact food of the Calaveras warbler, and its voice seems to be the same as that of the Nashville, but the following accounts of its habits seem worth quoting. Grinnell and Storer (1924) write:
The forage range of this warbler lies chiefly in trees other than conifers. Such trees as the black oak and big-leafed maple renew their foliage every spring and the Calaveras Warblers find excellent forage in the insects and larvae which feed upon this tender new leafage during the spring and summer months. Less often these birds may be found in golden oaks and occasionally in Douglas spruces. They usually forage 25 to 40 feet above the ground, keeping within the stratum of new foliage, but they have been seen as low as 10 feet and as high as 70 feet above the earth. When within the foliage their yellow and green coloration makes it difficult to locate them, especially as the birds do not move about as rapidly as some of the other warblers. At times a Calaveras Warbler will poise on rapidly beating wings to capture some insect otherwise out of reach.
Dr. J. C. Merrill (1888) calls them “restless, shy, and very difficult to shoot”, and says further, “When alarmed, as they very easily are, the males move rapidly through the trees, often flying a hundred yards or more at once, and were it not that their constant song indicates their movements, it would be impossible to follow them. I have frequently followed one for half an hour or more before I could even catch a glimpse of it, and my pursuit of any particular one was more often unsuccessful than the reverse.* * *I have never found a land bird more wary and difficult to shoot. But as soon as the young leave the nest this extreme shyness disappears, and the parents arereadily approached and observed as they busily search for food for their young family.”
Dr. William T. Shaw, who collected a specimen of this warbler in northwestern Washington, says in his notes: “This warbler, a singing male, was noticeably a percher upon high, isolated cedar poles when singing, having three or four favorite ones in his territory, which was a hillside grown to a height of about 15 feet with second-growth deciduous trees, following fire. He sang from a height of from 30 to 40 feet up near the top of these old widely-scattered, fire-blasted, weather-bleached trees, clearly out in the open and isolated from green sheltering foliage beneath him, in such a location as one is accustomed to seeing lazuli buntings perch when they sing.” Dr. Shaw thought the first part of the song suggested that of Macgillivray’s warbler, and the latter notes reminded him of “those heard among the inspirational notes in the song of the lazuli bunting.”
The Bowles brothers (1906) say that, in the spring, the males have at times a very pleasing habit while singing, “that of hovering thru the air for a distance of fifteen or twenty yards. The manner of flying at these times is very slow and closely resembles that of one of the marsh wrens, but the beak is turned upwards and the feathers on the swelling throat separate until it seems almost certain that the bird will sing himself into some serious bodily mishap.”
VERMIVORA VIRGINIAE (Baird)
VIRGINIA’S WARBLER
Plate 18
HABITS
This warbler was discovered by Dr. W. W. Anderson, at Fort Burgwyn, New Mexico, and was described by Baird, in a footnote in The Birds of North America, by Baird, Cassin, and Lawrence (1860). The footnote occurs under the explanation of plates in the second volume. The warbler was named for Mrs. Virginia Anderson, wife of the discoverer.
Its range during the breeding season covers portions of Nevada, Utah, Colorado, Arizona, and New Mexico, mainly in the mountain regions, and it retires to Mexico for the winter. It seems to be more abundant in Colorado than elsewhere, breeding from the foothills, where it is a characteristic bird and perhaps the most abundant of the wood warblers, up to 7,500 to 8,000 feet in the mountains. On the spring migration, it is abundant along the valley streams, among thecottonwoods and willows, or sometimes among the pines; but in the summer it is found among the low scrub oak brush on the hillsides.
Bailey and Niedrach (1938) write attractively of Virginia’s warbler in its Colorado haunts:
In the broken prairie where the yellow pines have taken their stand upon the crest of the tableland, and in the rocky canyons clothed with the scraggly scrub oaks slipping down to narrow grass-grown creek-bottoms, Virginia’s Warbler chooses its nesting grounds.Plants seem to burst into life during the early weeks in May.* * *The flowers of the scrub oaks tinge the hillsides with a greenish-yellow bloom; the green of bursting leaves and grasses soon blends with the nodding blossoms of the pasque-flower; the beautiful pink plume sways on the hillside, and yellow blossoms of the Oregon grape thrust forth among the holly-like leaves, making one think of flowering Christmas wreaths. It is then that the Virginia’s Warblers are at the height of their activity. Their colors are the grays and yellows of the new vegetation. The males perch among scrub-oak branches and yellow pines, where they are usually concealed, and do their utmost to outsing their towhee neighbors.
In the broken prairie where the yellow pines have taken their stand upon the crest of the tableland, and in the rocky canyons clothed with the scraggly scrub oaks slipping down to narrow grass-grown creek-bottoms, Virginia’s Warbler chooses its nesting grounds.
Plants seem to burst into life during the early weeks in May.* * *The flowers of the scrub oaks tinge the hillsides with a greenish-yellow bloom; the green of bursting leaves and grasses soon blends with the nodding blossoms of the pasque-flower; the beautiful pink plume sways on the hillside, and yellow blossoms of the Oregon grape thrust forth among the holly-like leaves, making one think of flowering Christmas wreaths. It is then that the Virginia’s Warblers are at the height of their activity. Their colors are the grays and yellows of the new vegetation. The males perch among scrub-oak branches and yellow pines, where they are usually concealed, and do their utmost to outsing their towhee neighbors.
In Nevada, Ridgway (1877) first observed this warbler “among the cedar and piñon groves on the eastern slope of the Ruby Mountains.* * *On the Wasatch and Uintah Mountains it was more abundant, being particularly plentiful among the scrub-oaks on the foothills near Salt Lake City. They lived entirely among the bushes, which there were so dense that the birds were difficult to obtain, even when shot.”
In the Charleston Mountains, Nev., according to A. J. van Rossem (1936), “the distribution appeared to be limited to the so-called Upper Sonoran associations of mahogany and Gambel oaks, and therefore the species is considered characteristic of that zone, although the extremes of altitude at which it was found were 6,300 and 9,000 feet. Because of the relative scarcity of oaks, by far the greater number were found in mahogany which here grows as low, dense forest, instead of in the more familiar shrub form in which it is usually known.”
In the Great Basin region, Dr. Jean M. Linsdale (1938) found Virginia’s warblers in a variety of situations, such as “in sage on rocky, piñon-covered slope 100 yards from a stream; in sage on top of ridge; at tip of mountain mahogany tree; in plum thicket; singing and foraging through upper foliage of tall birches close to creek; in cottonwoods and piñons close to creeks; singing in dead shrub 10 feet high at base of rock slide; in aspen; in thickets of sage, elder,Ephedra, andSymphoricarpos; in willow; on ground among rocks at crest of ridge.” The altitudes ranged from 6,500 to 8,000 feet, with the largest number between 7,000 and 7,500 feet.
In southern Arizona, this warbler, according to Mr. Swarth (1904)—
proved to be very abundant during the spring migration, particularly in the lower parts of the mountains; but the most of them seem to go farther north, and butfew, compared with the numbers seen in April and the early part of May, remained through the summer to breed. The earliest arrival noted was on April 10th and soon after they were quite abundant, mostly in the oak region below 5000 feet, remaining so throughout April and up to the first week in May, at which time the migrating birds had about all passed on. All that were seen after that I took to be breeding birds, for they gradually moved to a higher altitude, (6000 to 8000 feet) and were nearly all in pairs. About the middle of April, 1902, I found a fewvirginiae, together with other migrating warblers, in the willows along the San Pedro River, some fifteen miles from the mountains.
Nesting.—Ridgway was evidently the first to record the nest of Virginia’s warbler, finding it near Salt Lake City on June 9, 1869. “The nest was embedded in the deposits of dead or decaying leaves, on ground covered by dense oak-brush. Its rim was just even with the surface. It was built on the side of a narrow ravine at the bottom of which was a small stream. The nest itself is two inches in depth by three and a half in diameter. It consists of a loose but intricate interweaving of fine strips of the inner bark of the mountain mahogany, fine stems of grasses, roots, and mosses, and is lined with the same with the addition of the fur and hair of the smaller animals” (Baird, Brewer, and Ridgway, 1874).
Shortly afterwards, a nest was found on June 1, 1873, in Colorado, by C. E. Aiken. It was reported by Aiken and Warren (1914) as “the first nest of this species known to science.* * *This was sunk in the ground in a tuft of bunch grass growing in a clump of oak brush, with the dead grass hanging over and completely concealing the nest, which was reached through a small round hole like a mouse hole through the protecting grass.”
Dr. Linsdale (1938) reports a nest found in Nevada, at an elevation of 7,700 feet, that “was at the lower edge of a clump of grass 20 inches tall and 2 feet across. The surrounding hillside was of small rocks lying at a maximum angle of rest. A few similar grass clumps were scattered near, about 10 feet apart. The surrounding trees were mountain mahogany and chokecherry. The nest was composed entirely of grass and was in a depression in the loose soil. It was well concealed by dead grass at the base of the tuft.”
In the Huachuca Mountains, Ariz., Mr. Swarth (1904) found a nest that “was built on a steep sidehill about ten feet from a much traveled trail, and was very well concealed; being under a thick bunch of overhanging grass, and sunk into the ground besides, so as to be entirely hid from view. This was at an elevation of about 8,000 feet, which seems to be about the upward limit for this species in this region.”
We found Virginia’s warbler fairly common there in the middle reaches of the canyons, around 7,000 feet, and found a nest being built at the base of a bush of mountain misery; Mr. Willard collected it with a set of three eggs on June 4, 1922; it was made of leaves and strips of bark and was lined with horsehair.
Another nest before me, from the Huachucas, has a foundation of moss and lichens, dry leaves, and strips of cedar bark, over which are finer strips of the bark and shreds of dry weed stalks and grasses, with a lining of still finer fibers; it is a shallow nest, its diameter being 3 by 31⁄2inches outside and 2 inches inside.
Eggs.—While 4 eggs seem to constitute the usual set for Virginia’s warbler, as few as 3 and as many as 5 have been reported. These are ovate to short ovate and only slightly lustrous. They are white, finely speckled or spotted with shades of reddish brown, such as “chestnut” and “auburn,” intermingled with faint specks of “pale vinaceous-drab.” Some eggs are profusely spotted over the entire surface, while others have the markings concentrated at the large end. The measurements of 40 eggs average 15.9 by 12.4 millimeters; the eggs showing the four extremes measure17.0by 12.4, 16.0 by13.0,14.2by 12.2, and 16.3 by11.2millimeters (Harris).
Young.—On the period of incubation and on the development and care of the young we have no information except the following observations of Bailey and Niedrach (1938): “The hatching time of many species of Colorado birds seems to coincide with an abundance of larvae feeding upon plants among which the birds are nesting. We have noticed time and again, that pests are numerous upon the vegetation when the fledglings are in the nest, but a few weeks later, after the little fellows have taken wing and are able to move to other parts, the caterpillars have gone into the pupa stage.” At a nest they were watching, they observed that both parents shared the work of feeding the young, averaging a trip every 6 minutes.
A. J. van Rossem (1936) took young birds that were not fully grown on July 10, and others on July 13 that had nearly completed the postjuvenal molt, from which he inferred that two broods might be raised in a season. H. S. Swarth (1904) noted that the young birds began to appear in the Huachuca Mountains about the middle of July, after which both old and young birds moved down into the foothills.
Plumages.—The young Virginia’s warbler in juvenal plumage is plain grayish brown above; the throat, chest, and sides are paler brownish gray; the abdomen and center of the breast white; the upper and under tail coverts are dull greenish yellow; there is no chestnut crown patch; and the greater and median wing coverts are tipped with dull buffy. The sexes are alike.
The postjuvenal molt begins early in July and is often complete before the end of that month. The first winter plumage is similar to that of the adult female at that season. In this plumage the sexes are not very different, and the crown patch is not much in evidence or is altogether lacking in the young female; both sexes are browner and with less yellow than in the adult plumage, and the female is duller than the male.
A partial prenuptial molt occurs between February and May, mainly about the head, during which the chestnut crown patch is at least partially assumed and the young birds become almost indistinguishable from adults. There is, however, considerable individual variation in the advance toward maturity.
Subsequent molts consist of a complete postnuptial molt in July and August, and a partial prenuptial molt in early spring. The adult male in the fall is browner above and on the flanks, and the yellow on the chest is duller than in the spring, while the chestnut crown patch is concealed by brownish gray tips. The female, also, is browner than in the spring, with little if any yellow on the chest and with the crown patch similarly concealed. In spring birds there is much individual variation, perhaps owing to age, in the amount of yellow on the breast, throat, and chin. Some females are nearly as brightly colored as are the duller males, some have very little yellow on the chest and some lack the chestnut crown patch.
Food.—Our information on the food of Virginia’s warbler is limited to the observation of Bailey and Niedrach (1938) who saw a pair of these warblers feeding their young on the caterpillars that eat the foliage of the trees and shrubs on their nesting grounds. It is significant that after these caterpillars are no longer available the warbler leaves its breeding haunts and moves down into the foothills, perhaps in search of other food; and it would be interesting to learn what that food is. It has been seen foraging on the ground, as well as in the foliage, and flying up into the air to capture insects on the wing.
Behavior.—Virginia’s warbler is a shy, retiring species, spending most of its time not far above the ground in the thick underbrush, where it is not easily seen, as its colors match its surroundings. It is also very lively and active, almost constantly in motion, except when it mounts to the top of some dead bush or small tree to sit and sing.
Voice.—Dr. Chapman (1907) quotes C. E. Aiken as follows: “The male is very musical during the nesting season, uttering hissweeditty continually as he skips through the bushes in search of his morning repast; or having satisfied his appetite, he mounts to the top of some tree in the neighborhood of his nest, and repeats at regular intervals a song of remarkable fullness for a bird of such minute proportions.” Henry D. Minot (1880) calls the "ordinary note, a sharpchip; song, simple but various (deceptively so); common forms areché-we-ché-we-ché-we-ché-we, wit-a-wiť-wiť-wiť(these terminal notes being partially characteristic ofHelminthophagae) andche-wé-che-wé-che-wé, ché-a-ché-a-ché". Dr. Linsdale’s (1938) comments on singing males follow:
The song varied from 7 to 10 notes, being usually 8, and it occupied about 3 seconds. At the beginning the notes were slow and they came more rapidly at the end. About half a minute elapsed between songs. Another bird sang14 times in 3 minutes and 10 seconds.* * *Singing perches on dead limbs that were rather exposed were the rule, but they were not often as high as the tops of tall trees.* * *On June 16, 1930, near Kingston Creek, 7500 feet, a singing male was followed for an hour, beginning at 7:30 a. m. It sang about every 30 seconds. The territory over which it moved was surprisingly large, estimated as extending 400 yards along the cañon slope and vertically about 150 yards, from near the stream to the base of the broken cliffs.* * *The song, compared with that of the Tolmie warbler had a more rapid rhythm and the notes were thinner and weaker. It could be distinguished from that of the Audubon warbler by the lack of rising inflection at the end. The song was represented by the observer (Miller) aszdl-zdl-zdl-zdl, zt-zt-zt-zt.
Field marks.—Virginia’s warbler, with its plain gray upper parts, is an inconspicuous bird, and its shy, retiring habits make it difficult to observe. The chestnut crown patch is not prominent and is often invisible. The yellow on the chest and throat of the male is quite variable and in the female and young much reduced or lacking. The best field marks are the dull yellow rump and upper and under tail covers, which are more or less conspicuous in old and young birds at all seasons.
Enemies.—O. W. Howard (1899) says that “the nests of the bird, like those of other ground-nesting birds of this locality, are destroyed by jays and snakes. The jays steal both eggs and young. Often a whole band of these winged wolves will sweep down on a nest and in less time than it takes to tell it they will devour the contents and destroy the nest, the pitiful notes of the helpless parents being drowned by the harsh notes of the marauders.”
Frank C. Cross writes to me that Robert J. Niedrach showed him a nest of this warbler that contained a young cowbird and one young warbler.
Winter.—By the last of August or early September, Virginia’s warblers have retired from their northern breeding haunts, to spend the winter in southern Mexico. Dr. C. William Beebe (1905) writes: “Occasionally in the mornings, numbers of tiny grayish warblers came slowly down the walls of thebarranca, feeding as they descended, taking short flights, and keeping close to ground among the dense underbrush. These birds lingered at the camp for a time, and then, with soft, low chirps, all passed on to the water, where they alighted on the sand and drank. Then, as if at some silent signal, all flew up and returned quickly, still keeping close to the ground, zig-zagging their way upward in a long line, like tiny gray mice.” These were, of course, Virginia’s warblers.
DISTRIBUTION
Range.—Western United States to Southern Mexico.
Breeding range.—Virginia’s warbler breedsnorthto central eastern California (White Mountains); central and northeastern Nevada(Kingston Creek, Ruby Mountains, and East Humboldt Mountains); northern Utah (Salt Lake City, Parley’s Park, Packs Canyon, and Ashley); possibly southeastern Idaho (Joe’s Gap, Bear Lake County; one specimen from Bancroft, Bannock County); and northern Colorado (probably Little Snake River, Moffat County, and Estes Park).Eastto the eastern slope of the Rocky Mountains in Colorado (Estes Park, Denver, Manitou, Fountain, and Beulah); in migration has occurred east to Limon, and Monon in Baca County close to the Kansas line; and central New Mexico (Tierra Amarilla, Lake Burford, Sandia Mountain, and Apache, probably).Southto southwestern New Mexico (Apache); and southeastern Arizona (Paradise and the Huachuca Mountains).Westto southeastern and central Arizona (Huachuca Mountains, Santa Catalina Mountains, and Prescott); and eastern California (Clark Mountain and White Mountains; casually in migration to Lemon Grove).
Winter range.—In winter Virginia’s warbler is found in west central Mexico from northern Jalisco (Bolanas); and Guanajuato (Guanajuato), to Morelos (Yautepec); and Guerrero (Talpa and Chilpancingo).
Migration.—A late date of spring departure is: Sonora—Moctezuma, May 10.
Early dates of spring arrival are: Texas—Socorro, April 20. New Mexico—Cooney, April 10. Colorado—Estes Park, May 2. Arizona—Madera Canyon, Santa Rita Mountains, April 2. Utah—Vernal, May 5. Nevada—South Twin River, April 30.
Late spring migrant in Brewster County, Tex., May 13.
Late dates of fall departure are: Utah—Vernal, September 20. Arizona—Tombstone, September 11. Colorado—Boulder, September 21. New Mexico—Koehler Junction, September 11. Texas—El Paso, September 16.
Early dates of fall arrival are: Arizona—Toprock, July 23. Texas—Toyavale, August 21. Sonora—Guadalupe Canyon, August 31.
Casual records.—Two specimens of Virginia’s warbler have been taken in western California: in San Diego County, on September 3, 1931; and at Prisoner’s Harbor, Santa Cruz Island, on September 8, 1948. Virginia’s warbler has been reported as occurring in Nebraska and Kansas, but there is no record of a specimen having been taken in either State.
Egg dates.—Arizona: 10 records, May 17 to June 21; 5 records, May 25 to June 4.
Colorado: 6 records, June 1 to 26.
Nevada: 3 records, June 8 to 15.
VERMIVORA CRISSALIS (Salvin and Godman)
COLIMA WARBLER
CONTRIBUTED BY JOSSELYN VAN TYNE
HABITS
Described in 1889 from a single specimen collected by W. B. Richardson in the Sierra Nevada de Colima, Mexico, this handsome warbler was, in 1932, still known from only a dozen museum specimens, and not a word had been recorded on its habits. In that year a University of Michigan expedition found the Colima warbler to be common in the higher forests of the Chisos Mountains of southwestern Texas and made the first discovery of its nest and eggs. The basis for the inclusion of this warbler in the A. O. U. Check-List had been a single specimen collected by Frederick M. Gaige in the Chisos in 1928 (Van Tyne, 1929).
The range of the Colima warbler has been recorded only very sketchily, but Bangs (1925) was probably correct in surmising that the specimens from southern Mexico (Colima and Michoacán) were migrant birds. The closely related Virginia’s warbler, which nests in the Rocky Mountain States, winters mainly in Michoacán, Guerrero, and Jalisco. Recently R. T. Moore (1942) added a second, more southerly, locality in Michoacán and one in eastern Sinaloa to the known southern range of the Colima warbler. The breeding range is apparently restricted to the highlands of northeastern Mexico and the Chisos Mountains of southwestern Texas. In Texas the Colima warbler occurs at altitudes between 6,000 and 7,500 feet (Van Tyne, 1936); in Coahuila, apparently, only above altitudes of approximately 7,500 feet (Burleigh and Lowery, 1942). Records from the southern part of its range, however, show a greater altitudinal spread. The type specimen was taken in Colima at about 8,000 feet, and R. T. Moore (1942) reports two November specimens, one taken at 9,500 feet in northeastern Michoacán, the other at 5,200 feet in Sinaloa. These represent the extremes of the known altitudinal range.
Courtship.—Mating behavior has been observed during the first few days of May and sets of eggs noted May 15 (just completed) and May 20 (highly incubated). The only recorded specimen in juvenal plumage was collected July 20. Peet observed pursuit behavior in the Chisos Mountains on May 4 (within a few days of nest building), which may have had some courtship significance, but nothing definite is known of the courtship habits. Sutton noted copulation twice on May 1 in the Chisos, and the gonads of specimens collected that day were much enlarged; there was no indication that the females had begun incubating.
Nesting.—Two nests, both in the Chisos Mountains, have been described. The first (discovered in 1932) was lodged between small rocks and deeply imbedded in dead oak leaves on the sloping bank of a dry stream bed. A dense ground cover of vines and other herbaceous plants arched completely over it, leaving an entrance only on the northwest side, toward the stream. The nest had a basic structure of loosely woven fine grasses, the outside reinforced with pieces of green moss and the rim with strips of cedar bark; the cavity (5 centimeters across the rim and 4 centimeters deep) was lined with fine grass, a little fur, and a few hairs (Van Tyne, 1936). The other nest, which was “on the ground, under a little bunch of oak leaves, at the edge of a talus slope, almost at the very base of the cliffs” (Sutton, 1935), was similar, but its basic structure included dry leaves, and the site was concealed by only a partial canopy of leaves (Van Tyne and Sutton, 1937).
Nest building was observed in the Chisos Mountains on May 7, 1932 (Van Tyne, 1936):