Moore (1957:246) reported this subspecies of the Yellow Warbler as
having been recorded from Coahuila.

_Dendroica auduboni auduboni_ (Townsend).--_Specimens examined:_ total
2: [Male] 31094 (skeleton only) from Fortin (=33 mi. N, 1 mi. E San
Geronimo), 3300 ft., March 29, 1952; and [Male] 31093 from 4 mi. W
Hacienda La Mariposa, 2300 ft., March 25, 1952, weight, 12.3 gms.

Audubon's Warbler is a common winter visitant and migrant in Coahuila.
Miller (1955a:173) recorded _D. a. auduboni_ as a migrant from April 7
to 26 in the Sierra del Carmen; he found no suggestion of breeding by
the Audubon's Warbler in the northwestern section of the State. One
individual that Miller (_loc. cit._) obtained was extensively black and
approached the characters of the subspecies _nigrifrons_ of Chihuahua.
He (_loc. cit._) suggested that the black individual was taken from
"part of a cline of blackness and size in which _D. a. auduboni_ of the
northwest and _D. a. nigrifrons_ of Mexico are extremes." Burleigh and
Lowery (1942:203) remarked that Audubon's Warbler "is doubtless a
common winter bird in the area around Saltillo." Two specimens obtained
by Burleigh and Lowery (_loc. cit._) "might be considered intermediate"
between _auduboni_ and _memorabilis_. Sutton and Burleigh (1939a:40)
saw Audubon's Warbler "in some numbers near San Pedro ... [on] January
29 and 30." Dickerman saw Audubon's Warblers 13 mi. E San Antonio de
las Alazanas on April 10, 1954. Miller (1955a:173) also obtained, in
the Sierra del Carmen, a hybrid between _D. coronata_ and _D.
auduboni_.

_Dendroica auduboni memorabilis_ Oberholser.--Oberholser (1921:246)
recorded _D. a. memorabilis_ from Saltillo on April 17. This subspecies
seems to winter commonly in western Mexico and less commonly in the
Central Plateau and Sierra Madre Oriental (Miller, Friedmann, Griscom,
and Moore, 1957:249-250).

_Dendroica nigrescens_ (Townsend).--_Specimen examined:_ one, [Male]
31095, from Fortin (=33 mi. N, 8 mi. W San Geronimo), 3300 ft., March
28, 1952, weight, 9.3 gms.

The Black-throated Gray Warbler is an uncommon spring and possibly fall
migrant in Coahuila. Miller (1955a:173) found _D. nigrescens_ uncommon
in the Sierra del Carmen. He saw and heard a spring migrant singing on
April 12 at 7000 feet and obtained a male on April 16.

_Dendroica townsendi_ (Townsend).--Townsend's Warbler is a spring and
fall migrant in Coahuila. Miller (1955a:173) recorded _D. townsendi_ o