Adult, 6,500′, Chihuahua, Mexico
Adult, Southwestern Mexico
Venter of Above-Pictured Animal
PLATEAU EARTH SNAKE
Conopsis nasus – Gunther 1858
IDENTIFICATION:
DISTRIBUTION:
This wide-ranging species is found throughout north-central Mexico. It occurs throughout the highlands of the Sierra Madre Occidental from eastern Sonora and southern Chihuahua south through Durango and Zacatecas to Jalisco (and probably Nayarit on the Mesa del Nayar); in the Sierra Madre Oriental it occurs from central San Luis Potosà south through Queretaro and Hidalgo then west into the Mexican Plateau where it reaches as far south as Morelos and Distrito Federal and as far west as Michoacán and Colima.
HABITAT:
Conopsis nasus is found throughout a wide-range of mid-high elevation habitats including rocky plateau, pine, oak, pine-oak and fir forests. Habitat in Chihuahua and Sonora is high-elevation Pine and Pine-Oak Forest. Conopsis nasus appears to be found most commonly in meadows and open areas along streams with abundant rock cover.
Habitat, 6,500′, Chihuahua, Mexico
Montane Habitat, Southern Mexico
NATURAL HISTORY:
This fossorial snake seems to be abundant throughout it’s range. It is diurnal, and seasonally nocturnal but is rarely found abroad during daylight hours. Prey items are primarily invertebrates and lizards (particularly the Genus Eumeces). Small frogs (such as Hyla) and young rodents are probably also occasionally consumed. Conopsis nasus appears most abundant during the summer rainy season (June-September). 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:
Conopsis nasus labialis Tanner is now considered a junior synonym of Conopsis nasus. Conopsis is closely allied to Gyalopion, Ficimia and Chionactis.
TYPE:
Described as Conopsis nasus by Gunther (1858). Neotype: BMNH 83.4.16.38 Type-locality: Milpas, Durango, Mexico.
PERSONAL NOTES:
The Chihuahuan snake depicted above was discovered in April beneath a small, flat rock in an open area of a Pine-Oak forest at around 6500′ elevation. She was gravid, and was using a flat rock to thermoregulate against (her posterior half was placed up against the rock surface to warm her developing eggs, while the rest of her body lay within an earthen cavity).
In El Salto, Durango I found three neonate C. nasus beneath adjacent scattered rocks along a stream in August; they were no more than a few days old and beginning their first skin-shed cycle. Thamnophis eques virgatenuis and Thamnophis nigronuchalis were abundant here as well.
CONSERVATION STATUS:
Abundant and adaptable, Conopsis nasus is in no danger of wide-scale decline.
REFERENCES:
Goyenechea, I., and Flores-Villela, O. (2006) Taxonomic summary of Conopsis, Gunther, 1858 (Serpentes: Colubridae). Zootaxa 1271:1-27.
Gunther, A. (1858) Catalogue of colubrine snakes in the collection of the British Museum. Alden & Mowbray Ltd. Alden Press, Oxford, 281 p.
Taylor, E. H., and Smith, H. M. (1942) The snake genera Conopsis and Toluca. Univ. Kansas Sci. Bull. 28(15):325-363.