The copperhead (Agkistrodon contortrix) is a common venomous snake found across the eastern and central regions of North America. Unlike many other reptiles that lay eggs, the copperhead gives birth to live young. This process occurs primarily during the late summer and early fall months, meaning encounters with small, newly born snakes are most likely between late August and early October.
The Annual Reproductive Cycle
The reproductive cycle for copperheads begins with mating, which usually takes place in the spring after the snakes emerge from winter dormancy. A second, less frequent mating period can also occur in the late summer or fall. Female copperheads possess the ability to store sperm for several months, allowing fertilization to be deferred until conditions are optimal for gestation.
The timing of birth is somewhat variable, influenced by factors such as geographic location and ambient temperature. In general, the birth window spans from August through October, with the peak often occurring in late August and early September. Females typically produce a relatively small litter, with the average size ranging between four and eight young, though litters of up to 20 have been recorded. This late-season timing ensures that the young are born when temperatures are warm enough for their immediate survival and independence.
Live Birth and Gestation
Copperheads reproduce through ovoviviparity, meaning the eggs develop and hatch internally within the mother’s body. The female retains the developing embryos, encased in a thin membrane, until they are ready for birth. This process results in the delivery of fully formed, live young, though it differs from true live birth where a placenta provides nourishment.
The gestation period typically lasts about three to four months following the spring mating. During this time, the pregnant female, or gravid snake, spends a significant amount of time basking in warm, safe areas to regulate her body temperature. Proper thermoregulation is important for the development of the fetuses, and the female often seeks sheltered spots like under rocks or logs. This internal incubation period culminates in the birth of the young, each emerging individually wrapped in an amniotic sac that they break free from shortly after delivery.
Identifying Newborn Copperheads
Newborn copperheads measure between 7 and 10 inches in length. Their body pattern is essentially the same as an adult’s, featuring the distinctive hourglass crossbands on a background of tan or pinkish-brown skin. The neonate’s overall coloration is often duller or more grayish than the mature adult.
The most identifying feature of a young copperhead is the bright, contrasting color of its tail tip, which is typically neon yellow or greenish-yellow. This vibrant coloration persists for about a year before it begins to darken and match the adult’s body color. Newborn copperheads are born fully equipped with potent venom and fangs, and they are completely independent from the moment of birth.
Immediate Behavior and Habitat
Births often occur in secluded, protected locations, such as under rocky crevices, dense vegetation, or beneath large logs. In some cases, multiple females may gather in specific areas, sometimes near their winter den sites, to give birth, forming a temporary birthing rookery. This choice of location minimizes the distance the vulnerable newborns must travel to find a suitable winter hibernation spot.
Immediately after birth, the young snakes disperse quickly, beginning their independent lives without parental care. They use their brightly colored tail tip in a behavior called caudal luring. By wiggling the yellow tip, the snake mimics the movement of a small insect or worm, attracting small prey like frogs and lizards within striking distance.