Colorado, Kansas and New Mexico residents are advised to be on the lookout for venomous male tarantulas, who will be fanning out from now until October.
Some arachnid and wildlife experts have called it a ‘mate-gration’ as the males are known to sometimes travel as many as 20 miles in search of a mature female partner.
‘They’re just out looking for love,’ as one Houston Texas-based entomologist and spider expert, Dr Lauren Davidson, put it. ‘Let them go find a girlfriend.’
Dr Davidson is just one of many scientists who hopes that public fears about spiders won’t interrupt their ecologically valuable quest to reproduce more of their species.
The Lone Star State’s own brush with these tarantulas in heat only just concluded this month — as its female tarantulas now prepare to give birth to gigantic broods via oozing egg sacs that can harbor anywhere from 50 to 3,000 baby spiders.
Some arachnid and wildlife experts have called it a ‘mate-gration’ as tarantula males are known to sometimes travel as many as 20 miles in search of a mature female partner in parts of the southwestern US from August to October. Above, tarantula on Copper City Road in California
Above, Colorado State University PhD candidate Jackie Billotte releases a female tarantula close to her old den after making a plaster of Paris mold of the tarantula’s den on the Southern Plains Land Trust Heartland Ranch Nature Preserve on September 24, 2022 near Lamar, CO
Although the American tarantula is a venomous species, it tends to save its fatal toxins for prey like beetles, grasshoppers, small lizards, mice, and even scorpions.
Humans can typically withstand a bite from these tarantula’s without so much as a hospital visit, but that doesn’t mean this influx of male spiders is without its perils.
Dr Ritch Reading, vice president of science and conservation at the Butterfly Pavilion in Westminster, Colorado, told Fox 21 local news that spider enthusiasts sometimes put themselves in harm’s way to ogle or photograph these tarantulas on the move.
‘When we go down there, we see people on the roads, and these cars and trucks do move quite fast,’ Dr Reading said. ‘You see people on their hands and knees taking pictures — and I would not recommend that.’
‘If a truck comes speeding at 65 to 70 miles an hour and you’re on your hands and knees,’ he continued, ‘you might not be able to evade that vehicle.’
With that warning in mind, Dr Reading added that several local highways in Colorado were, in fact, the best spots for naturalists to witness the migration for themselves.
Highways 109 and 350 near the La Junta area, he noted, have substantial tarantula populations and are good for sightings around dawn and dusk.
‘Tarantulas use hydraulics, instead of muscles, to move their legs,’ according to Dr Reading. ‘If it’s too hot or too cold, those hydraulics don’t work very well, and so they actually won’t move when the weather’s really warm.’
‘The best time to see them at this time of year is in the mornings and the evenings when it’s a little bit more moderate,’ he explained.
When a male finds an ideal female spider with whom to mate, he will perform a courtship dance that includes tapping his legs on a female’s web.
If she is receptive, she might reciprocate the drumming.
Once successful fertilization has occurred in a female tarantula, she constructs a golf ball-sized egg sac, in which she will lay her eggs.
Above, a female tarantula releases an oozing egg sac containing more than 1,700 offspring
Enthusiasts come out every year to observe the male tarantulas on their mating trek
She then protects the egg sac from predators until potentially hundreds or thousands of little spiderlings hatch.
After mating, males typically 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, some experts say.
In the wild, tarantula hawks — the largest wasp in the US — sometimes inject these spiders with a paralyzing venom and drag them back to a burrow.
The wasp, always a female who is ready to lay eggs, then stuffs the paralyzed tarantula down the hole of the burrow and lays her eggs atop the paralyzed spider.
When the eggs hatch several days later, the larvae feed on the still-living tarantula.