Voice.—Aretas A. Saunders sends me the following note on the song of this warbler: “I have had few opportunities to study the song of the Cape May warbler, and have only five records. These show that the song is weak, high-pitched and somewhat sibilant. The notes are mainly all on one pitch, in even rhythmic time and from eight to eleven in number. They are pitched on E‴´ and F‴´. Two of the songs have one or two notes, near the end, a half-tone higher in pitch than the others. The songs are from 13⁄5 to 2 seconds in length.”
Francis H. Allen (MS.) heard one singing and feeding in some Norway spruce in West Roxbury, Mass., on May 10. “He had chip notes very much like a familiar note of the chipping sparrow. (I have also recorded a prssp like that of the black-poll warbler but fainter and sometimes doubled.) This bird had a variety of songs. The simplest one resembled the black and white warbler’s song and a short simple song of the redstart, but was thinner and harder in quality than the latter. Then there were other, more elaborate songs, some divided into two parts and some into three. Two or three times he sang several times with no pauses between, making what was practically a long continuous song. The chief characteristic of the songs, I should say, was short and staccato double notes, the latter part of which were very high-pitched. These repeated several times formed the simplest of the songs. The song in three parts reminded me of that of the Tennessee warbler, but was higher pitched and not so full and loud. The bird had long periods of silence, but sang freely when he did sing.”
Brewster (1938) says that “the song of this Warbler is harder—or at least sharper and more penetrating—than that of either the Bay-breast or Blackburnian. In these respects it resembles the song of Protonotaria but the tone or quality is more wiry and, indeed, very close to that of Mniotilta.”
Field marks.—The adult male Cape May warbler should be unmistakable in his brilliant spring plumage, with his black cap, chestnut cheeks, white lesser wing coverts, and bright yellow breast conspicuously streaked with black.
The female lacks the black cap and chestnut cheeks; her breast is pale yellow streaked with pale dusky; and all her colors are duller. Young birds are much like the female, but are still duller in coloration. See descriptions of other plumages. The tail-tilting habit is quite pronounced.
Fall.—The fall migration starts in August and is prolonged through September, or even into October or a little later. The birds are numerically more abundant in the fall because of the large families of young, but they are less conspicuous while the foliage is still on the trees and while they are clad in dull autumn and immature plumages. Deciduous woods seem to be their favorite haunts at this season. The migration route is a reversal of the spring route, the main flight being between the Mississippi and the Alleghenies.
In this area, the birds are often excessively abundant, as shown by the accounts in the preceding paragraphs under food. They are common in Florida on migration on their way to the Bahamas and West Indies. C. J. Maynard (1896) writes:
“They were very abundant at Key West in November, frequenting the gardens near the houses where they were searching among the tropical trees and shrubs for inesects. The birds were very unsuspicious, often clinging to branches which overhung the sidewalks within a few feet of the passengers. They appeared to prefer the inhabited portion of the Key, for I rarely found them in wooded districts. The majority left the island before the first of December, but a few remained all winter.”
Winter.—Maynard (1896) says: “These birds are also common on all of the northern Bahamas which I have visited, occurring in the thickets about gardens as well as in the dense scrub. I found them abundant on Inagua in February, 1888. Here they were feeding upon the juices of a large tubular flower of a peculiar species of vine, in company with the Bahama Honey Creeper and the Lyre-tailed Hummingbird.”
In Cuba, according to Dr. Barbour (1923), “a few arrive from time to time during the autumn, but in February they become really common; they stay until May. They are great flower feeders and haunt aloes and the majagua tree when it is in bloom. Many may be seen about the sisal plantations near Matanzas and in gardens where agaves blossom.”