Timber Rattlesnakes - Gravid females basking to bring young to term (Crotalus horridus). Northeastern USA. Venomous pitvipers, widely distributed throughout eastern United States. Legally protected in 8 of 32 states in which it occurs. Populations declining due to habitat loss and direct persecution. Occurs in two color morphs--black and yellow. Female bear live litters of 3-14 young every 3-5 years. Feeds mainly on small mammals captured through ambush. Ectothermic (cold-blooded)--relies heavily on rocky, south-facing outcrops for basking. Generally mild-mannered in comparison to other rattlesnake species.