Mexico Herpetology

TWO-LINED MEXICO EARTH SNAKE
Conopsis biserialis - Taylor & Smith 1942

IDENTIFICATION:

DISTRIBUTION:
Conopsis biserialis is distributed along the southern edge of the Mexican Plateau and Cordillera Volcanica from Jalisco, eastward through the states of Guanajuato, Michoacán, Estado de Mexico, Morelos, Distrito Federal, Hidalgo and Puebla (possible Tlaxcala as well). This snake occurs as far north as southwestern Queretaro but has yet to be officially recorded there. Elevational distribution from 1700-3080 m.

HABITAT:
This species is found in rocky plateau, pine forest, oak forest and even montane cloud forest from 1700-3080 m elevation. It is most common in clearings, open areas, and meadows. Most often this snake is discovered beneath surface objects such as rocks, logs and trash.

Plateau Habitat, 3,500′, Michoacan, Mexico

NATURAL HISTORY:
This fossorial snake seems to be abundant throughout it’s range. It is primarily diurnal, but is rarely found abroad during daylight hours; during the summer it may also be active on warmer evenings. Prey items are primarily invertebrates and lizards (particularly the Genus Eumeces). Small frogs (such as Hyla) and young rodents are probably also consumed. This species is Ovoviviparous, giving birth to a small litter during the summer rainy season, normally in July/August. Conopsis is preyed upon by Diadophis regalis.

TAXONOMY:
Goyenechea & Flores-Villela (2006) synonomized the Genus Toluca with Conopsis.

TYPE:
Described as Conopsis biserialis by Taylor & Smith (1942). Holotype: FMNH 100062. Type-locality: 10 miles W Villa Victoria, Estado de Mexico, Mexico.

PERSONAL NOTES:
I have seen this species in northwestern Michoacán on several occasions. The first was a DOR individual found on a cold night in August; one Crotalus polystictus was also seen on this night. In July, 2005 I found several of these snakes beneath rocks in a grazed field on a warm day. Other common snakes found in this habitat were: Diadophis dugesi, Lampropeltis ruthveni, Crotalus aquilus, Crotalus polystictus, Crotalus basiliscus, Salvadora bairdi and Thamnophis eques eques. Unfortunately at the time I was under the impression these snakes represented Conopsis nasus, and I failed to take any photographs.

CONSERVATION STATUS:
This species appears not to be in any small or large-scale decline despite the fact that a large portion of it’s habitat has been altered by human activity. It is abundant and adaptable.

REFERENCES:
Goyenechea, I., and Flores-Villela, O. (2006) Taxonomic summary of Conopsis, Gunther, 1858 (Serpentes: Colubridae). Zootaxa 1271:1-27.
Taylor, E. H., and Smith, H. M. (1942) The snake genera Conopsis and Toluca. Univ. Kansas Sci. Bull. 28(15):325-363.