Colorado’s tarantulas are something of an enigma. It’s not exactly a state famous for big spiders. The Rocky Mountains and cold plains of Colorado don’t seem like prime tarantula habitat, either. However tarantulas in Colorado definitely do exist, and in fact put on quite a display each year in the southeastern corner of the state.
2 Tarantulas in Colorado
Unfortunately, there hasn’t been a whole lot of research done on Colorado’s tarantulas. Most of what we know about them is based the information collected about the same species from other states.
Depending on who you ask Colorado has 2, 3 or 5 species of tarantula. There has long been debate in the scientific community on distinguishing individual species. At the time of writing this article, we are following the recent review that has consolidated several formerly separate species. We will include all former names of Colorado tarantulas below, but currently there are only 2 species of tarantulas in Colorado.
1. Texas Brown Tarantula
Scientific name: Aphonopelma hentzi (synonymous with Aphonopelma coloradanum and Aphonopelma echinum, formerly considered separate species)
This is one of the most common and widespread tarantulas in the Southern United States. It can be found in Colorado, Kansas, Missouri, Arkansas, Oklahoma, Texas, New Mexico, and Louisiana. In part due to this wide distribution it has gone by many other names including the Oklahoma brown tarantula or Missouri tarantula.
It’s a big spider, growing to over four inches in leg span. While coloration can vary, it’s typically a brown color that can blend in with a variety of different vegetation and soil types, giving it a lot of flexibility for habitat.
Like most tarantulas, it likes to spend most of its time hidden in a burrow underground. The burrows are about a foot deep, and consist of a vertical shaft ending in a horizontal side chamber.
At night, they climb to the mouth of the burrow, where they wait to ambush their prey. In Colorado, it will plug up the entrance to the burrow during the winter months and go into a sort of hibernation, waiting to emerge again until the spring.
Brown Tarantula Mating Season
Mature tarantulas rarely leave the vicinity of their burrow, and will spend almost their entire lives their. The exceptions are mature males, who migrate over large distances in late summer in search of a mate.
The mating season for the brown tarantula has become somewhat of a tourist attraction in La Junta Colorado, in the southeastern part of the state. During September, male tarantulas leave their homes in search of mates. Hundreds of them are seen roaming around town, especially crossing from one side of Highway 109 to the other.
These brown tarantulas like to mate and nest in grasslands and parries, and La Junta’s close proximity to the Comanche National Grassland makes it a prime spot for this annual “migration”. For more info about how best to view the annual tarantula migration in La Junta, check out this page.
2. Aphonopelma marxi
Scientific name: Aphonopelma marxi (also synonymous with Aphonopelma vogelae)
Colorado’s other tarantula, sometimes called the Grand Canyon Black Tarantula, is often thought of as a “mini tarantula”. This smaller spider rarely exceeds 1.5 inches in length. It is a dark brown or black color, and lives in burrows.
These mini tarantulas are a very difficult species to study because their favored habitats are somewhat remote, and its small size makes it hard to find. The burrows are proportionally small too, so locating one and waiting for a spider to emerge is a challenge.
They are found in the Four Corners region, where Colorado, Utah, New Mexico, and Arizona meet. They prefer to live in higher elevations, and can inhabit a wide range of habitats including conifer forests and sagebrush plains.
The species Aphonopelma vogelae was previously listed as a separate species in Colorado, however it is now considered the same species as Aphonopelma marxi.