Tarantulas evoke a mix of fascination and apprehension. Many wonder if these large, hairy spiders inhabit Colorado. Indeed, tarantulas are native residents of the state. This article explores their presence, detailing their characteristics, preferred habitats, and what to know should an encounter occur.
Tarantulas in Colorado
Colorado is home to several tarantula species, with the Texas Brown Tarantula, Aphonopelma hentzi, being the most common and widely recognized. This arachnid is also known by other names, including the Oklahoma Brown Tarantula or Colorado Brown Tarantula, reflecting its broad distribution across the southern United States. These ground-dwelling spiders typically burrow into the earth for shelter.
The Texas Brown Tarantula is a large spider, characterized by its hairy body and legs. Its coloration ranges from a rich to dark brown, often with a slightly lighter brown on its cephalothorax, the fused head and chest region. Adult females can have a body length of about two inches, while males are slightly smaller but possess longer legs, with leg spans often reaching up to five or six inches.
Where Colorado Tarantulas Live
Tarantulas in Colorado primarily inhabit the southeastern plains and grasslands of the state. Areas such as those south of the Arkansas Valley, including counties like Fremont and Prowers, and around towns like La Junta, Pueblo, and Canon City, are known for their tarantula populations. This semi-arid environment provides the dry, sandy soil ideal for these spiders to dig their deep burrows.
These spiders are largely nocturnal, spending their days hidden within their silk-lined burrows, which offer protection from predators and extreme temperatures. However, during late summer and early fall, particularly in September and October, male tarantulas become more active. This period marks their mating season, as mature males leave their burrows and embark on journeys to find receptive females.
These wandering males can travel considerable distances, sometimes covering tens to hundreds of meters each evening in their search for a mate. Females, in contrast, tend to remain close to their burrows throughout their lives. Consequently, most tarantula sightings during the day occur during this autumnal “mate-gration,” when males are out in the open.
Encountering a Colorado Tarantula
Colorado’s tarantulas are generally docile creatures and are not aggressive towards humans. Their primary defense mechanisms are not typically directed at people unless they feel directly threatened. When disturbed, a tarantula’s first instinct is to retreat and hide.
One of their defense mechanisms involves “urticating hairs,” tiny, barbed bristles located on their abdomen. If provoked, a tarantula can kick these hairs into the air, which can cause irritation, itching, or a rash upon contact with human skin. While generally mild, these hairs can be more irritating if they get into the eyes or are inhaled.
Tarantulas also possess venom, which they primarily use to subdue their insect prey. A bite from a Texas Brown Tarantula to a human is uncommon and typically causes symptoms comparable to a bee sting, such as localized pain, swelling, and redness. Serious reactions are rare, though allergic responses are possible for some individuals.
If you encounter a tarantula, observe it from a respectful distance. Avoid handling or provoking the spider, as this might trigger its defense mechanisms. Allowing these arachnids to continue their journey undisturbed is the recommended course of action.