The Affinities of Chamæthlypis.—As generic distinctions become more and more refined the need of a supergeneric group intermediate between the family or subfamily and the genus, corresponding approximately to the former genus, becomes increasingly evident.
In his great work on the ‘Birds of North and Middle America’ Mr. Ridgway has supplied this want in many families. In the Warblers (Mniotiltidæ) the grouping does not appear to be so successful as in most cases. Not only is the old genus Geothlypis broken up into three genera but these are distributed in as many supergeneric groups. Oporornis is banded with Dendroica and its allies in the Dendroicæ, while Chamæthlypis is placed in the Icteriæ.
We cannot help feeling that this arrangement is artificial, and that too much importance has been placed on the length of the wing-tip (easily modified by habits and migration), and insufficient weight given to coloration, nesting and even song.
Also, the distinctions are partially invalidated by exceptions. Thus the sections including Geothlypis and Chamæthlypis are separated by differences in the length of the tail and form of the bill; but Geothlypis nelsoni agrees with Chamæthlypis in having the tail longer than the wing. Again the Geothlypeæ are separated from the Dendroiceæ by having the rictal bristles obsolete and the wing-tip shorter, but in Geothlypis æquinoctialis and G. cucullata, at least, the rictal bristles are well-developed.
The particular point of criticism is in regard to the affinities of Chamæthlypis which is distinguished from Geothlypis by its stouter bill, with strongly curved culmen, and its longer, graduated tail.
Mr. Ridgway expresses the opinion that while “this genus is very much like Geothlypis as to its general appearance” it is “quite distinct structurally, in which respect it comes much nearer to Icteria.” I have carefully tabulated the structural differences between these three genera, and the result to my mind unquestionably indicates a nearer relationship of Chamæthlypis with Geothlypis.
Sharpe (Hand-List of Birds) while recognizing Chamæthlypis, included in this genus two South American species of Geothlypis, G. æquinoctialis and G. auricularis. These two species and G. cucullata are intermediate between Chamæthlypis and the typical species of Geothlypis in coloration and in the form of the bill and have well developed rictal bristles as in Chamæthlypis. They do not, however, approach the latter genus in the length of the tail, as do certain Mexican species of Geothlypis, notably G. nelsoni.
While in Nicaragua in the spring of 1917 I had the opportunity of hearing the song of the ‘Ground-chat’ on several occasions. It is a highly musical warble resembling that of Geothlypis semiflava bairdi but even superior; the songs of both these species much excel that of G. trichas. The song of Chamæthlypis possesses nothing whatever of the eccentric qualities of the Yellow-breasted Chat’s vocal performance.
In conclusion, the evidence of size, coloration, external structure and song, strongly indicate the near relationship of Chamæthlypis with Geothlypis and the more remote affinity of the former with Icteria. The first two genera are, in fact, practically connected by intermediate species.—W. DeW. Miller, American Museum of Natural History, New York City.
Blue-winged Warbler Feeding a Young Field Sparrow.—On June 16, 1918, I was passing through a brushy area near Norwalk, Conn., when my attention was attracted by a Blue-winged Warbler (Vermivora pinus) evidently much excited at my presence as though it had a nest or young in the vicinity. It carried a green caterpillar about with it, as though wishing to feed young, so I sat down to watch it. A Field Sparrow (Spizella pusilla) soon appeared and also manifested excitement at my presence. After some waiting the Blue-wing approached a certain point in the bushes so frequently, that I got suspicious and searched it, finding to my surprise a young Field Sparrow, evidently just out of the nest and unable to fly. I waited some time longer, hoping to find the young of the Blue-wing, and finally the latter got over its fear, and approached the young Field Sparrow, and fed it the caterpillar it had been carrying. The adult Field Sparrow remained nearby but would not go to the young bird.