In the wild, there are not a lot of species that start rearing young during this part of the year. In barely a month or less, we could have our first frost. A lot of migratory birds are heading back …
In the wild, there are not a lot of species that start rearing young during this part of the year. In barely a month or less, we could have our first frost. A lot of migratory birds are heading back south as you read this, as they have completed their breeding activities months ago. Yet there is a species that has just given birth to its young.
The timber rattlesnake (Crotalus horridus) gives birth to live young around the start of September. The breeding process actually started a year back when mating took place during the previous summer. Female timber rattlesnakes only become gravid (with young) every two to three years.
The females have the ability to store the sperm from the summer mating over winter, during hibernation. Fertilization with the stored sperm takes place about a month after emergence during spring. All spring and summer, these gravid females did little else besides bask in the sun in rocky areas with ledges, near crevices to crawl into if they need to hide from predators.
The female rattlesnakes may move to nearby gestation sites, but the snakes don’t move far. When a female rattlesnake is gravid, it eats little or nothing during the season.
Many females may share the same gestation site. The embryos inside the bodies of the females require warmth, but not too much warmth. On a hot summer day, they will likely be in the crevices during the middle of the day. Since they are cold-blooded, this is the only way snakes can regulate their body temperature.
In our region, gravid females give birth from late August to early September. The average litter size is four to eight young.
After birth, the young remain in the same area as the female (and other adult females) for about two weeks. About a week after birth, rattlesnake young shed for the first time. After a couple of weeks after they leave the immediate gestation site, they must find their way to the hibernacula; they do this by following scent trails left by other adult snakes. This occurs around the beginning of October.