Desert tarantulas, (Milne and Milne, 1980), are common throughout the Southwestern United States, especially Arizona, New Mexico, and Southern California.
The male emerges from its burrow at sunset and then again near dawn. A male tries to maintain contact with the female, and if she pulls away, he will actively pursue her.
Males have two specialized claws that are shaped like syringes on the ends of its two pedipalps. Male (Miller, 1988)weave a purse to hold the sperm, which he then loads into the specialized claws. Females have two pouches on the abdomen that are designed to hold the sperm sacks. Sperm sacs can be stored for weeks or months in the female's abdomen until she is ready to lay her eggs. As a female lays her eggs, she bathes each egg in the sperm (Miller, 1988). She weaves a silken sheet and lays up to 1,000 eggs on it. After laying all her eggs, she weaves another sheet, covers the eggs, and then seals the edges. After making this egg sac, a female carries it up to the edge of her burrow to warm it in the sun. Females guard their egg sac until the eggs hatch in up to 7 weeks (Miller, 1988). Three to six days after hatching, the young leave the nest and venture out on their own.
Females care for their offspring in a number of ways. In addition to making a safe place for the eggs to hatch, and provisioning those eggs with nutrients, females actively help the eggs incubate by keeping them warm in the sun. Presumably, the female provides protection for the young spiderlings as they live in and around her burrow until they are three to six days old. (Miller, 1988)
Male and female desert tarantulas have very different life expectancies. While it takes approximately 8 to 10 years to become sexually mature for both sexes (Miller, 1988), males, after molting for the last time, live for approximately 2 to 3 months. Females, however, continue to molt (shed their exoskeleton as they grow), and may live for up to 20 years. In captivity, females have been known to live for 25 years (Milne and Milne, 1980). (Miller, 1988; Milne and Milne, 1980)
Desert tarantulas are reclusive, nocturnal spiders. They usually hide in their burrows, under rocks, or in abandoned holes during the daylight hours (Milne and Milne, 1980). They hide because they are more vulnerable to predators such as birds and snakes during the day; additionally, their prey are also mainly nocturnal. Between June and December, males can be seen between twilight and sunrise actively searching for females (Miller, 1988). (Miller, 1988; Milne and Milne, 1980)
spends much of the day hiding in its burrow. When the sun sets, it emerges and begins to search for food.
Foods eaten: lizards, crickets, beetles, grasshoppers, cicadas and caterpillars. (Safra, 1998)
is not endangered in any way.
Nancy Shefferly (editor), Animal Diversity Web.
Ben Craighead (author), Southwestern University, Stephanie Fabritius (editor), Southwestern University.
living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.
having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.
an animal that mainly eats meat
in deserts low (less than 30 cm per year) and unpredictable rainfall results in landscapes dominated by plants and animals adapted to aridity. Vegetation is typically sparse, though spectacular blooms may occur following rain. Deserts can be cold or warm and daily temperates typically fluctuate. In dune areas vegetation is also sparse and conditions are dry. This is because sand does not hold water well so little is available to plants. In dunes near seas and oceans this is compounded by the influence of salt in the air and soil. Salt limits the ability of plants to take up water through their roots.
animals which must use heat acquired from the environment and behavioral adaptations to regulate body temperature
fertilization takes place outside the female's body
union of egg and spermatozoan
An animal that eats mainly insects or spiders.
offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).
having the capacity to move from one place to another.
the area in which the animal is naturally found, the region in which it is endemic.
active during the night
reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.
the business of buying and selling animals for people to keep in their homes as pets.
remains in the same area
reproduction that includes combining the genetic contribution of two individuals, a male and a female
mature spermatozoa are stored by females following copulation. Male sperm storage also occurs, as sperm are retained in the male epididymes (in mammals) for a period that can, in some cases, extend over several weeks or more, but here we use the term to refer only to sperm storage by females.
uses touch to communicate
that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).
Living on the ground.
defends an area within the home range, occupied by a single animals or group of animals of the same species and held through overt defense, display, or advertisement
an animal which has an organ capable of injecting a poisonous substance into a wound (for example, scorpions, jellyfish, and rattlesnakes).
movements of a hard surface that are produced by animals as signals to others
uses sight to communicate
young are relatively well-developed when born
Jackman, J. 1997. A Field Guide to Common Texas Insects. Houston, Texas: Gulf Publishing.
Miller, G. 1988. Texas Monthly Field Guide to Wildlife in Texas and the Southwest. Austin, Texas: Texas Monthly Press.
Milne, L., M. Milne. 1980. The Audobon Society's Field Guide to North American Insects and Spiders. New York, New York: Alfred A. Knopf.
Safra, J. 1998. The New Encyclopedia Britannica Volume II, 15th Edition. Chicago, Illnois: