The Amphibians and Reptiles of Sinaloa, Mexico - Smithsonian ...

AMPHIBIANS AND REPTILES OF SINALOA, MEXICO 65
Tropical Dry Forest.—The dry forest is found in the southern
parts of the state. This environment is characteristically more moist
than the other lowland zones and is inhabited by 73 species and
subspecies of amphibians and reptiles. Most species that are
abundant in the seniiarid forest are also abundant in the dry forest;
additionally, Iguana iguana and Drymobius margaritiferus are considered
abundant in dry forest. In the lowlands certain species
are almost restricted to the dry forest. Among these are Phrynohyas
venulosa, Syrrhophus modestus, Gastrophryne usta, and Leptodeira
maculata. Other species that occur to the north are conspicuously
rare or absent in the dry forest. Included are Gastrophryne olivacea,
Coleonyx variegatus, Callisaurus draconoides, Holbrookia maculata,
Phyllorhynchus browni, and Salvadora hexalepis.
Subtropical Dry Forest.—Relatively little is known about the
herpetofauna of this vegetation type in Sinaloa, due to the inaccessability
of areas having subtropical dry forest. As presently
understood 54 species and subspecies have been recorded in this
zone. Many records are from localities at the periphery of the
range of primarily lowland species. There is, however, a distinctive
group of species characteristic of this vegetation type. Included
are Eleutherodactylus hobartsmithi, E. occidentalis, E. vocalis,
Tomodactylus niditus, T. saxatilis, Hyla smaragdina, Rana pustulosa,
R. sinaloae, Eumeces colimensis, E. parvulus, Gerrhonotus kingii,
Dryadophis cliftoni, Leptodeira splendida, Rhadinaea hesperia, and
Crotalus stejnegeri. Some of these species range into the lowlands,
usually along riparian habitats. Others are recorded from higher
elevations. An increase in moisture and a well developed Utter on
the forest floor probably are important factors determining the
distributions of these forms in the subtropical dry forest as opposed
to zones previously discussed.
Lower Montane Dry Forest.—This vegetation type is restricted
to high elevation in scattered localities along the Sierra Madre
Occidental in eastern Sinaloa. The only site visited in the montane
forest was on Highway 40 near the Durango border. Ten species
of amphibians and 21 species of reptiles have been collected in this
habitat. Characteristic species include Rufo occidentalis, Hyla
arenicolor, Sceloporus bulleri, S. jarrovii, S. shannorum, Gerrhonotus
liocephalus, Conopsis nasus, Geophis dugesii, Storeria storerioides,
and Crotalus lepidus. Most of these are widely distributed on the
Mexican plateau, or are restricted to high elevations in the mountains
of western Mexico.