notes, wrote that at a place 13 mi. E San Antonio de las
Alazanas, 9345 feet, a large flock of about 300 birds was in a
spruce-fir-pine-aspen association.
*_Coccyzus americanus americanus_ (Linnaeus).--_Specimens examined:_
total 2: [Male] [Male] 32037-32038 from 12 mi. N, 12 mi. W Jimenez, 850
ft., June 19, 1952, measurements: wing, 141, 146 mm.; tail, 142, 149
mm.; tarsus, 27, 27 mm.; culmen, 25, 24 mm.
In Coahuila, the Yellow-billed Cuckoo seems to be uncommon. It occurs
in the northeastern section of the State, in the Gulf Coastal Plain
(Baker, 1956:128), and probably breeds there. One subspecies,
_americanus_, has been recorded from Coahuila.
According to Ridgway (1916:13-17) the difference between _C. a.
americanus_ and _C. a. occidentalis_ is size. His (_loc. cit._) average
measurements of males of _occidentalis_ are: wing, 149.6 mm.; tail,
147.1 mm.; tarsus, 26.7 mm.; and culmen, 27.7 mm. whereas average
measurements given by him of males of _americanus_ are: wing, 143.6
mm.; tail, 140.7 mm.; tarsus, 25.2 mm.; and culmen, 26.4 mm. Van Tyne
and Sutton (1937:35) question the value of maintaining the subspecies
_occidentalis_, because individuals of _americanus_ and _occidentalis_
are almost impossible to tell apart. Friedmann, Griscom, and Moore
(1950:132) stated that _americanus_ occurs in eastern North America
whereas _occidentalis_ occurs in western North America. If the
subspecies _occidentalis_ exists, then Nos. 32037 and 32038 are, by
size, _americanus_ and No. 32038 is an intergrade between the two
subspecies (or a large individual of _americanus_).
The Yellow-billed Cuckoo was seen also by Findley 2 mi. S and 3 mi. E
San Juan de Sabinas on June 22, 1952, and by Dickerson at Torreon on
July 2, 1955. The sizes of the testes of the birds from 12 mi. N and 12
mi. W Jimenez (9, 10 mm. long) and the date (June 19) on which they
occurred there indicate that the birds possibly were breeding.
_Coccyzus erythropthalmus_ (Wilson).--Miller (1955a:163) reported a
migrant Black-billed Cuckoo taken in the maples and basswood near a
water hole in the bottom of Boquillas Canyon in the Sierra del Carmen,
5200 feet, on April 22. Friedmann, Griscom, and Moore (1950:132)
reported that this cuckoo is presumably a regular transient in Mexico,
but generally overlooked.
*_Geococcyx californianus_ (Lesson).--_Specimen examined:_ one,
[Female] 32049, from 8 mi. N, 2 mi. W Piedras Negras, June 18, 1952.
Miller (1955a:1
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