Arachnophobes, look away now! Thousands of TARANTULAS crawl across Colorado as spiders begin their annual mating season
- Between late August and early October, male tarantulas make a mating journey across southeastern Colorado
- The adult male spiders are looking for adult females with which to reproduce before they die for the winter
- Each year, enthusiasts come out to observe the spiders as they travel through parts of Colorado’s grasslands
In a few weeks, hordes of tarantulas will begin their annual crawl across southeastern Colorado for their mating season.
Tarantulas are generally found in the southwestern United States, including southern Colorado, where a few enthusiasts show up each year to see the fully grown adult male tarantulas on the mating procession, or “mate-gration.”
Although the annual episode is sometimes colloquially referred to as a migration, in reality the tarantulas search for mates.
When male tarantulas, about two inches tall, reach adulthood, which happens between eight and ten years old, they start looking for a mate. The trek usually takes place between late August and early October.
Males sometimes travel as far as 20 miles in search of an adult female with whom to reproduce. Often the males travel in groups as they search.
Each year in late summer, male tarantulas begin their mating quest, which involves trekking up to 20 miles in search of a female tarantula with whom to reproduce
The tour takes place through parts of the American Southwest, including a small corner of Colorado’s southeastern territory
When a male finds an ideal female spider to mate with, he will perform a courtship dance where he taps a female’s web with his legs.
If she’s receptive, she can answer the drumming.
Once a female tarantula is successfully fertilized, she will build a golf ball-sized egg sac in which she will lay her eggs.
She then protects the egg sac from predators until possibly hundreds of tiny spiders hatch.
After mating, males die relatively quickly. Threats include predators, cars, and a general lack of interest in eating anything. In some cases, the female spider may eat the male.
Female tarantulas have a typical lifespan closer to 20-25 years.
In some cases, tarantula hawks — the largest wasp in the US — inject the spiders with paralyzing venom and drag them back to a burrow.
The wasp, always a female ready to lay eggs, then stuffs the paralyzed tarantula into the burrow hole and lays her eggs on top of the paralyzed spider.
When the eggs hatch several days later, the larvae feed on the still-living tarantula.
Enthusiasts come out every year to observe the male tarantulas on their mating journey
The male tarantulas usually die not long after mating
Tarantulas are most active in the afternoon, especially the last hour before sunset
A director of Colorado’s Butterfly Pavilion — America’s first non-profit insect zoo — Sara Stevens told a local point of sale where she thinks people can go to observe tarantulas on their migration.
Stevens said Highway 109 on the Comanche Nation Grassland is a good viewing spot, as are parts of La Junta, where the La Junta Tarantula Fest is held.
The combination has clearly become an integral part of La Junta’s municipal identity, as the festival includes a parade, vendors, and tarantula tours, among other things.
The Comanche National Grassland, right at the southeastern tip of the state, is a state grassland, which Stevens says usually has a higher concentration of tarantulas.
Tarantulas are most active in the afternoon, especially the last hour before sunset.
They are not poisonous to humans, although bites can be painful.