73: Tarantulas
I write to you from Arapahoe, Ute, and Cheyenne land. I am interested in learning about the different animals that live in the place where I was born. Before we start with today’s animal, I want to emphasize that biological classification as understood by western society has its roots in racism, sexism, and transphobia – here’s a good explainer about why.
Tarantulas: they’re pretty cool. The last time I saw one in the wild was in early December 2016 in the Kasha-Katuwe Tent Rocks National Monument south of Santa Fe. It was sunning itself on a rock right next to the trail. It was pretty chilly out that morning so I imagine the red rock surface was very nice and warming. Tarantulas are all members of the family Theraphosidae, which has over 1000 species currently known. They are named for the Italian town of Taranto, although the spiders who originally bore the name tarantula were actually wolf spiders, who are from a different family. In Colorado, there are five species of tarantula, all of whom live in the warmer parts of the state – the larger ones live in the southeast, while there are two species of mini tarantula who live in the arid deserts of western Colorado, in Montezuma, San Miguel, Mesa, Dolores, and Montrose counties. Colorado also has wolf spiders who are often mistaken for tarantulas.*
Tarantulas in Colorado excavate burrows that can be a foot deep and make a door using a veil of silk (fancy!). During the day, they generally hang out inside their burrow before emerging at dusk to hunt. The tarantula then sits beside its burrow and waits for passing insects before rushing forward, grabbing its prey with its pedipalps (remember those from the scorpions?) and then impaling it with its fangs. Late in the season, the spider makes a plug at the burrow’s entrance, and then seals itself in for the cold winter months.
For being such small creatures, tarantulas have long incubation periods (50-60 days for laid eggs to hatch, during which time they are kept wrapped in silk in the burrow and occasionally brought out into the sun to warm) and long lives – males take 7-10 years to reach sexual maturity, while females can take 1-2 more years than that. After the males undergo their final molt, they leave their burrows to seek out a mate. This will be their final journey – they won’t live through the winter that follows. The females, meanwhile, stay by their burrows and can live up to ten years after that final molt, laying eggs each year.
One Colorado town advertises the migration of the male tarantulas as a tourist attraction – La Junta, out on the southeastern plains, offers some helpful tips for how to take in the annual event.
People are often scared of tarantulas, but they are actually gentle animals who make good pets (and good museum demonstration animals, I can say from experience). Their venom can’t harm humans and they will only bite if handled very roughly. So make a tarantula your friend today!
*Want to tell true tarantulas apart from wolf spiders? For one, wolf spiders have distinctive large eyes. For another, tarantulas move their jaws vertically, whereas almost all other spiders, including wolf spiders, move their jaws horizontally. Obviously this requires you to get quite close – wait until its cold and you can find them sunning themselves lazily!