Adult, 2,000′, Sonora, Mexico
Adult, 2,000′, Sonora, Mexico
Neonate, 2,600′, Pima County, Arizona
SONORAN LYRE SNAKE
Trimorphodon lambda – Cope 1886
IDENTIFICATION:
DISTRIBUTION:
Trimorphodon biscutatus lambda is found nearly statewide in Sonora, from the Sierra Pinacate and associated Lava Flow near Sonoyta, to the foothills of the Sierra Madre Occidental along the Chihuahua border; it also occurs in extreme western and northwestern Chihuahua and south throughout the majority of the state of Sinaloa to the vicinity of the Nayarit border. Elevational distribution is from sea level to at least 6,500′.
HABITAT:
Habitat, 200′, Sonora, Mexico
Habitat, 100′, Sonora, Mexico
Madrean Woodland Habitat, 6,000′, Hidalgo County, New Mexico
NATURAL HISTORY:
TAXONOMY:
TYPE:
PERSONAL NOTES:
In Mexico, I have found T. lambda in the state of Sonora. My first experience with this species in Mexico was an AOR snake on the road running through the town of San Carlos, on the Gulf of California west of Guaymas. Subsequently I have found this snake to be relatively common in areas of Sinaloan Thornscrub and Sonoran Desert influences. It occurs in sympatry with Trimorphodon tau tau.
In the United States I have had quite a bit of experience with this species in the Santa Catalina Mountains, near Tucson, Arizona. In August and September, 2004 I made nightly excursions into the mountains to keep tabs on snake activity and road-related fatalities and found an average of 2 neonate lambda per night, making them the most abundant reptile encountered by far. It is interesting to note that every single lambda seen was a recent hatchling.
One unsuspected run-in with this snake was in August, 2005 in the Peloncillo Mountains at an elevation of 6,000′. Friends and I located two of these snakes: one within a deep fissure, and another underneath a shallow flake of rock. The rock outcrops were south-facing, and located within Madrean Oak Woodland with abundant Manzanita and Pine. This association puts this snake in sympatry with Crotalus lepidus klauberi and Crotalus willardi obscurus.
CONSERVATION STATUS:
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