Dwarf Mexican Garter Snake
Thamnophis nigronuchalis
A small-bodied garter snake of the Sierra Madre Occidental in northwestern Mexico, notable for a dark nape marking.
- Venomous?
- Mildly venomous
- Adult length
- 0.3-0.5 m (12-20 in)
- Range
- Sierra Madre Occidental, northwestern Mexico
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Overview
The dwarf Mexican garter snake is a diminutive species known from highland habitats of the Sierra Madre Occidental in northwestern Mexico. Its small adult size compared to other Thamnophis species gives rise to its common name.
Its limited distribution and specialized habitat requirements make it a species of conservation interest, though detailed population data is scarce.
How to identify it
- Small overall size relative to most garter snakes
- Dark blotch or patch on the nape (back of the neck), reflected in its scientific name
- Olive to grayish dorsal coloring with faint striping
- Keeled scales
- Round pupils
Habitat & range
Restricted to highland streams and wetlands of the Sierra Madre Occidental in northwestern Mexico, typically at moderate to high elevations.
Behavior, diet & reproduction
Diurnal and semi-aquatic, foraging near water for small prey such as amphibians and invertebrates. Mild venom aids prey handling and is harmless to humans. Reproduces via live birth.
Frequently asked questions
Why is it called 'dwarf'?
Because it reaches a notably smaller adult size than most other garter snakes.
What marking helps identify it?
A dark patch on the nape, just behind the head.
Where is it found?
In highland habitats of the Sierra Madre Occidental in northwestern Mexico.
Is it dangerous to humans?
No, it is only mildly venomous to prey and harmless to people.
Dwarf Mexican Garter Snake guides
In-depth guides for identifying and understanding Dwarf Mexican Garter Snake.
