Drivers in many parts of New Mexico this week may literally stop in the middle of the road to watch the annual migration of amorous male tarantulas on the hunt for females.
Summers with ample rain bring out the eight-legged creepy crawlers in big numbers on their quest to continue their species. While they don’t seek out highways, they will travel as far as 50 miles in search of a mate and somewhere on that route often lies a road.
Photographer David Tremblay recently encountered a tarantula single-mindedly moving across the landscape to his goal.
“Every year at this time, the males are out looking for the females. You will find them walking across the roads everywhere, you just have to look closely,” Tremblay said. “Try not to run over the grisly things, they mean no harm to us.”
The one he photographed was in the middle of the road.
“Male tarantulas live 10 to 12 years. Females can live twice as long,” he said. “Predators of tarantulas include lizards, snakes, spider-eating birds, coyotes and foxes.
“Tarantulas are nocturnal hunters. They feed primarily on insects like grasshoppers, beetles, other small spiders and arthropods, and will sometimes eat small lizards.”
Tarantulas are found worldwide. Those in North America live in the southern and southwestern states, with many other species to the south throughout Mexico, Central and South America.
They are very sensitive to vibrations in the ground that may indicate the presence of prey or danger, Tremblay said. They are equipped with urticating hairs on their abdomen that can be released by kicking with their back legs; these hairs irritate the nose and eyes of would-be attackers.
“I’ve read that they are docile, but they can leap nearly five feet into the air,” Tremblay said.
Margie Klein, a certified environmental educator, wrote in “Desert USA: A Guide to the American Southwest” that males definitely received the short straw in life. Females stay in and around their burrows and wait for suitors to appear. They use their legs to send vibrations to attract male suitors, sometimes killing the ones she rejects. Sometimes, she even kills the one she accepts as a mate. If a male manages to evade her deadly fangs after completing the 10-second deed, he may die of exhaustion or live a few more years. The females can notch up 20 years and they have the opportunity to grow much larger than the males.
An arachnid is more closely related to crayfish than insects. A tarantula is about the size of a large doughnut with a leg span of about 4 inches to 5 inches. They are nocturnal hunters and instead of entrapping prey in their webs, prefer to use their eight eyes and short pedipalps appendages to hunt them down.
Prey is injected with a venom that liquefies the inside of their bodies. The tarantula uses a sucking technique to ingest its meals.
In winter, they can go into torpor, which is similar to hibernation, but with warmer temperatures allows them to snap out of the slow sleep and hunt.
But the tarantula also can be prey for lizards, snakes, birds, foxes and coyotes, as well as the female Pepsis wasp, also known as the tarantula hawk, which finds tarantulas in their burrows and lays its eggs on the spider. When they hatch, the larvae consume the tarantula.
The bite from North American tarantulas can be painful, but rarely harms a human. If provoked, a tarantula can flick its barbed hair onto skin, causing irritation.
Males usually seek a mate at about the age of three. The oldest known by science was 12 years, while females can live 20 or more years and produce from 500 to 1,000 young at each mating, Klein wrote.
The Desert Tarantula is one of about 50 species of terrestrial tarantulas native to the Southwest and Central United States, Tremblay said.
“What makes tarantulas look hairy is the thousands of hair-like filaments or fine bristles that cover much of their bodies,” he said. “The main function of these hairs called setae is to help the spider, which has very poor eyesight, sense the presence of prey, determine wind direction, identify chemical signatures and assess other vital elements of its environment.”
The most common place to find tarantulas is in softer soil areas. Their burrow openings are the size of a penny with silk around it.