Part 15

_Behavior._--The eastern Nashville warbler is an active, sprightly, restless member of an active family, ranging in its foraging mainly in the lower story of the open woodlands and more often in the low trees and shrubbery around the borders of the forest. When thus engaged it is not particularly shy and often seems quite unconscious of the presence of an observer. On migrations it seems to be sociably inclined and may be seen associated with the mixed flocks of warblers that are drifting through the tree tops. At these seasons it often visits our orchards and the shrubbery in our gardens, giving us a glimpse of green and gold among the blossoms and opening leaves.

J. W. Preston (1891) describes an interesting manner of foraging:

"One will fly to the foot of a fir tree or other conifer and begin an upward search, hopping energetically from branch to branch until the very highest point is reached, when the bird drops lightly down to the foot of another tree, much as does the Brown Creeper. When an insect is discovered the bird secures it by a sudden bound, and, should the object be not easily dislodged, _Helminthophila_ sustains himself on flapping wings until his purpose is accomplished, which often requires several moments."

_Voice._--Gerald Thayer gave Dr. Chapman (1907) a very good description of the songs and calls as follows:

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 few _chippings_ added, at both ends. Among the Nashville's calls a very small, dry _chip_, and a more metallic, louder _chip_, somewhat Water-Thrush-like, are noteworthy. It also _chippers_ like a young Warbler or a Black-throated Green.

Miss Stanwood (1910a) writes:

One common song sounds like _'tsin, 'tsin, 'tsee_, another _sweeten, sweeten, 'tsee_, a third, _sillup, sillup, sillup, 'tsee-e-e-e-e-e_. At other times the bird sings but part of the song as _sweeten, sweet_; or _sweeten, 'tsee_; or _sweeta, sweeta, 'tsee_; or recombines them differently as _sweeten, 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 a half or two tones. They are from 1-2/5 to 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 breed =north= to 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). =East= to southeastern Quebec (Natashquan River and the Magdalen Islands); and Nova Scotia (Baddeck, Halifax, and Barrington). =South= to 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). =West= to 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 winter =north= to central Durango (Chacala); western Nuevo León (Monterrey) and southern Texas (Somerset and Matagorda County). =East= to southern Texas (Matagorda County, Rio Hondo, and Brownsville); eastern Puebla (Metlatoyuca); western Veracruz (Jalapa); Chiapas (Chicharras); and central Guatemala (Barillos, Panajachel, and San Lucas). =South= to Guatemala. =West= to 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 name _gutturalis_. 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 of bushes, 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 road along 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 1-1/4 inches 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 measure =16.6= by =13.2=, =14.3= by 11.9, and 16.0 by =11.5= millimeters (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.