Baja California Lyre Snake, Trimorphodon lyrophanes

Baja California Lyre Snake, Trimorphodon lyrophanes. Snake photographed in the bush in the greater Los Cabos area, Baja California Sur, November 2022.  Photograph courtesy of Dr. John Warner, Colorado Springs, Colorado. Identification courtesy of Gary Nafis, Californiaherps.com.

The Baja California Lyre Snake, Trimorphodon lyrophanes, is a member of the Colubridae family of North American Racers, Coachwhips, and Whipsnakes. The Colubridae family comprises two-thirds of the world’s snake population with one thousand seven hundred sixty species placed in two hundred forty-nine genera. Many Colubrids are classified as venomous but very few are considered to be dangerous to humans. There are seven species in the Trimorphodon genus. They are named for the markings on their head which resembles a lyre. The Baja California Lyre Snake is also known as the California Lyre Snake and the Peninsular Lyre Snake and in Mexico as Culebra Lira de Baja California and Vibora de Uña. 

The Baja California Lyre Snake is slender with a broad head that is well-differentiated from its slim neck and vertical pupils, like those of a cat. Their coloring closely matches the snake’s habitat, ranging from gray to light brown. There are usually 35 dorsal splotches that have light edges and a pale crossbar in the center and smaller irregular blotches on the lower sides. Their underside is off-white or yellowish with dark spots and they have a lyre-shaped marking on the top of their head. Hatchlings are often black and white in color. Adults range between 61 cm (2 feet 0 inches) to 91cm (3 feet 0 inches) in length while hatchlings are approximately 15.2 cm (6.0 inches) in length. The Baja California Lyre Snake is nocturnal and remains active in very dry conditions as well as during rains. While they are primarily terrestrial, they are also good climbers. During the day, they can be found inside crevices in large rock outcrops where they shelter from the heat and search for prey. Their diet mainly consists of lizards, small mammals, nestling birds, and snakes. The Baja California Lyre Snake is poorly studied with very limited information available about their lifestyle and behavioral patterns including specific details on age, growth, longevity, movement patterns, diet, habitat use, and reproduction.

The Baja California Lyre Snake may be confused with the other species of lyre snake found in California, the Sonoran Lyre Snake, Trimorphodon lambda. These species can be differentiated visually. The Sonoran Lyre Snake has fewer blotches that are more widely separated compared to the Baja California Lyre Snake. 

From a conservation perspective, the Baja California Lyre Snake is currently considered to be of Least Concern. While the total adult population size is unknown, it is presumed that this secretive snake is more numerous than available records indicate. No major threats have been identified but locally, excessive collection for the pet trade has likely caused a reduction in their abundance. Baja California Lyre Snakes are considered to be not dangerous to humans because they may produce a mild venom that does not typically result in death, serious illness, or injury in most humans. However, they should still be handled with caution and their bite should be avoided. They are utilized by the pet trade on a limited basis.