Timber rattlesnakes have a very complex reproduction cycle, as do most animals.  They undergo sexual reproduction only and are dioecious, meaning that males and females exist as separate individuals. For males, sexual maturity is reached at around three to four years of age, while females can take up to eleven years. Since timber rattlesnakes have life expectancies of about twenty years, females are only able to reproduce two or three times during their lifetime.  For this reason, females tend to breed only every two to four years, three being the most common.   Breeding season usually occurs in the spring and fall, but prime breeding times occur in July and August.  Mating rituals are highly competitive, and consist of males participating in combative wrestling matches with other males in order to gain the attention of a female.  The successful male will go on to mate with the female, who is capable of storing sperm for up to a year.  The sperm is stored during the winter months for use in the spring when the females ovulate. In June, the female’s ova are fertilized internally and thus, gestation begins.  Like other pit vipers, timber rattlesnakes are ovoviviparous, meaning they do not lay eggs outside of the body.  Instead, the embryos develop in eggs that are incubated and hatched within the mother’s body and then birthed as live young.  Each egg contains an amnion, which serves as a protective membrane that surrounds the developing embryo.  The egg also contains an egg yolk sac that provides nourishment for the developing embryo as well as many other membranes that aid in the embryo’s growth.  During gestation, females spend most of their time near their hibernation dens or basking in the sun to keep their body temperature at an optimal level.  Also, contrary to mammals like us, females tend to eat less during this period of gestation and remain relatively inactive. The yolk sac mentioned earlier provides sufficient nourishment during embryonic development that newborns do not usually need to feed until well after birth.  Therefore, overconsumption by the mother during gestation is  unnecessary.  By late August and early September, gravid females are about ready to give birth.  Litter size can vary greatly among different populations, but the typical range is from about 5 to as many as 20 newborns.  After hatching inside the female’s uterus, the young are born live and are encased in individual membranes similar to that of the amnion.  Each rattlesnake can be up to 7 to 13 inches in length when born and are capable of delivering venomous bites equivalent in danger to that of a full-grown rattlesnake.  Young timber rattlesnakes, like in the picture to the right, possess very small rattles within the first few years of life.  After  their skin sheds a few times, rattles will develop to their full size.  During the first week, mothers will provide shelter and protection for their young from predators, but after that, they exhibit very little parental care.



Back To Home Page
To learn more about the Nutrition/Interactions of this organism, click here