Burke Museum Home

Reptiles of Washington


Rubber boa
(Charina bottae)

 

What they look like

  • Rubber boas are small, stout, and smooth snakes ranging in average length from 21 to 26 inches.
  • Females are slightly longer than males.
  • Body colors range in different shades of brown, with their bellies light yellow.
  • Young are born pink and gradually develop their darker adult colors.

Where they live

  • Even though they tend to live in the same small patches of land year after year, rubber boas overall range from southern California all the way to British Columbia.
  • Can also be found in Idaho, western Wyoming, central Montana, northern Nevada, and Utah.
  • Rubber boas are adaptable to nearly any sort of habitat but, since they are not very heat tolerant, they are not as likely to be found in open places of warm weather.
  • Prefer to spend much of their time in cooler and moist areas like under logs, rocks, and rodent burrows. 

What they eat

  • Rubber boas are nocturnal hunters.
  • They primarily prey upon the small vulnerable young of underground-nesting mammals (like voles, deer mice, and shrews).
  • Oftentimes have scars on their tails from mother rodents trying to protect their young.
  • Rubber boas can also feed on lizard and snake eggs.

Breeding

  • Female rubber boas give live birth to two to eight young in the late summer or fall.
  • Each baby snake weighs only 7.5 grams and is 7 to 11 inches long.
  • Young rubber boas move-out during spring after their first hibernation and reach maturity at around 2 to 3 years old.

Cool Biology Facts

  • Hunters from certain Native American tribes wore rubber boa tails as charms believing they would help protect against grizzly bears.
  • In order to help tolerate extreme cold, rubber boas can maintain a higher internal temperature around their head than the rest of their body or surrounding environment, hence safeguarding their brains at a safe warm temperature. Some rubber boas have even been recorded with body temperatures less than 44°F!
  • Rubber boas often curl up into a ball when threatened, looking like a ball of rubber and perhaps a reason for their name.

Photo

Distribution Map

Threats

Rubber boas are common species with seemingly healthy populations throughout their wide range. Main threat is over-collection for the pet trade, although it is currently illegal to sell wild-caught rubber boas in the United States.