Basin wiki · Animals
Desert tarantula
Aphonopelma · Aphonopelma iodium
A burrow spider you mostly notice in fall, when males walk the roads in daylight looking for a mate.
Where you'll see it
The park describes a large tarantula, Aphonopelma iodium, in Joshua tree woodland and creosote scrub, including around the Oasis of Mara. The same animals live on basin lots. Most of the year they stay in a silk-lined burrow. From about September into October, males wander, including across Highway 62, and that is the week everyone has a photo.
How to tell it
A heavy, hairy spider a few inches across, brown to black, with eight eyes packed on the front of the body. Females stay home and can live many years; the park says females may live 20 years or more, and that males may be eaten during mating. Taxonomy of Aphonopelma has been revised since some park labels were written, so treat the scientific name as the park’s current label and the animal as a desert tarantula either way. A smaller, faster spider on the kitchen wall is something else.
Bite versus bristles
The park notes they are reluctant to attack people and that the venom is no worse than a bee sting for most of us. The more common injury is the urticating hairs they kick off the abdomen when bothered: those itch and inflame eyes and skin. Do not pick one up to move it. Let a male cross the trail or the patio. If one is in a doorway, a cup and a stiff card, or just patience, beats a shoe. People with a known bee-sting allergy should treat a bite as a medical question, not a folklore one.
Leave the burrow
They eat beetles, grasshoppers, and other small prey, and they are not a house infestation. Spraying the yard for “tarantula season” mostly hits everything else. Burrows in a bank should stay open. Males on the road are easy to run over in numbers during those fall weeks; they are slow, and they are the breeding population. Step around them. In the park, the same hands-off rule applies as for every other animal.