REPRODUCTION AND HATCHLINGS
MATING BEHAVIOR
Tortoises are natural loners. They do not need
other tortoises for “company.” In fact, in the average size yard,
because the female cannot get away from the male, the constant courting
of a male may be very stressful and debilitating for a female.
Reproductive readiness is determined by size rather than age. Females are
usually ready when the length of the carapace (upper shell) is about 7- 8".
The number of years for a tortoise to reach this size depends upon how well
it eats. A wild tortoise may be 15-20 years old before it breeds, a well-fed
pet, half that age. See Table 1 for how to measure tortoise size.
Sexual differences become quite evident when the shell is about 7" long. Until
that size, the plastron (lower shell) of both sexes is flat. Males begin to
develop a concave plastron near the tail. A female’s plastron remains almost
flat throughout life. See arrows in Figure 29.
Figure 29. The gular horn under the chin
becomes longer and more upturned in
the male. He also develops an enlarged
gland on each side of the lower jaw and
a concave plastron near the tail. The
female has a shorter tail and longer
rear nails.
Courtship and mating may occur any time that tortoises are not hibernating.
Typically, the male bobs his head at the female and nips at her front legs and the
front edges of her shell. This usually makes her stop and pull in her head and limbs.
The male then moves around to her rear and mounts. See Figure 30. This differs from
fighting, wherein tortoises try to flip one another over.
Figure 30. Mating occurs any time
other than during hibernation. Females
store sperm and may lay fertile eggs for
several years after separation from a
male.
Nesting. Eggs are usually laid from early May to mid-July. Two clutches may
be laid several weeks apart. The incubation period is about 90 to 120 days, depending
upon the temperature in the nest. Using her hind legs with their long nails, the
female digs a nest, a shoe-shaped hole about 4" deep. The nest is often inside the
burrow. Nesting takes several hours.
Eggs. The number of eggs tends to be greater the larger the female. A typical
clutch from a wild female is 4-8 eggs, but pet tortoises tend to grow larger and may
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