<P> The number of burrows used by desert tortoises varies spatially and temporally, from about 5 to 25 per year . Some burrows are used repeatedly, sometimes for several consecutive years . Desert tortoises share burrows with various mammals, reptiles, birds, and invertebrates, such as white - tailed antelope squirrels (Ammospermophilus leucurus), woodrats (Neotoma), collared peccaries (Pecari tajacu), burrowing owls (Athene cunicularia), Gambel's quail (Callipepla gambelii), rattlesnakes (Crotalus spp .), Gila monsters (Heloderma suspectum), beetles, spiders, and scorpions . One burrow can host up to 23 desert tortoises--such sharing is more common for desert tortoises of opposite sexes than for desert tortoises of the same sex . </P> <P> Tortoises mate in the spring and autumn . Male desert tortoises grow two large white glands around the chin area, called chin glands, that signify mating season . A male circles around female, biting her shell in the process . He then climbs upon the female and insert his penis (a white organ, usually only seen upon careful inspection during mating, as it is hidden inside the male and can only be coaxed out with sexual implication) into the vagina of a female, which is located around the tail . The male may make grunting noises once atop a female, and may move his front legs up and down in a constant motion, as if playing a drum . </P> <P> Months later, the female lays a clutch of four to eight hard - shelled eggs, which have the size and shape of ping - pong balls, usually in June or July . The eggs hatch in August or September . Wild female tortoises produce up to three clutches a year depending on the climate . Their eggs incubate from 90 to 135 days; some eggs may overwinter and hatch the following spring . In a laboratory experiment, temperature influenced hatching rates and hatchling gender . Incubation temperatures from 81 to 88 ° F (27 to 31 ° C) resulted in hatching rates exceeding 83%, while incubation at 77 ° F (25 ° C) resulted in a 53% hatching rate . Incubation temperatures less than 88 ° F (31 ° C) resulted in all - male clutches . Average incubation time decreased from 124.7 days at 77 ° F to 78.2 days at 88 ° F (31 ° C). </P> <P> The desert tortoise grows slowly, often taking 16 years or longer to reach about 8 in (20 cm) in length . The growth rate varies with age, location, gender and precipitation . It can slow down from 12 mm / year for ages 4--8 years to about 6.0 mm / year for ages 16 to 20 years . Males and females grow at similar rates; females can grow slightly faster when young, but males grow larger than females . </P>

How many babies does a desert tortoise have
find me the text answering this question