Taxonomy
- Kingdom: Animalia
- Phylum: Chordata
- Class: Reptilia
- Order: Squamata
- Suborder: Serpentes
- Family: Leptotyphlopidae
- Genus: Rena
- Species: Rena humilis (Baird & Girard, 1853)
Common names
Western blind snake, western slender blind snake, western threadsnake.
Description
Rena humilis is a small, fossorial snake that resembles an earthworm. Adults are typically less than 30 cm (12 in) in total length and have a cylindrical, worm‑like body that is as thin as a pencil lead. The coloration ranges from pink and purple to silvery‑brown, with a shiny, reflective sheen. Eyes are vestigial, appearing as light‑detecting black eyespots, and the head bears a single ocular scale. The skull is robust to facilitate burrowing, and the tail ends in a small spine used for leverage. Under ultraviolet light the snake exhibits fluorescence.
Distribution
The species is native to the southwestern United States and northern Mexico. In the United States its range includes:
- Trans‑Pecos Texas, extending west through southern and central Arizona, southern Nevada, southwestern Utah, and southern California.
In Mexico it occurs in the states of Baja California, Sonora, Sinaloa, Nayarit, Jalisco, Colima, Chihuahua, Durango, Coahuila, and Tamaulipas.
Habitat
R. humilis inhabits arid and semi‑arid environments where it can burrow in loose soil, sand, or leaf litter. It is most often encountered after rains or when soil is disturbed, emerging briefly to the surface.
Behavior and Ecology
The snake is non‑venomous and primarily feeds on ants, termites, and other small invertebrates. Its reduced eyes reflect a subterranean lifestyle; vision is limited to light detection. The species is oviparous, laying small clutches of eggs in underground nests.
Conservation status
The International Union for Conservation of Nature (IUCN) lists Rena humilis as Least Concern (IUCN 3.1), indicating that the species does not currently face significant threats across its broad range.
Subspecies
Six subspecies are recognized as valid, including the nominate subspecies R. h. humilis.
References
- Wikipedia: “Rena humilis” (accessed via r.jina.ai).
- Reptile Database entry for Rena humilis.
- NatureServe Explorer species profile for Rena humilis.