Squirrels, flying-squirrels, porcupines, civet-cats, rats, bats, flying-foxes and lizards are found in great variety; snakes of various kinds, from the boa-constrictor downward, are abundant, while the forests swarm with tree-leeches, and the marshes with horse-leeches and frogs.
The policy of the government which protects game, both in the park and in the surrounding national forests, has induced elk, deer, antelope, mountain-sheep, bears, porcupines, coyotes, squirrels, gophers and woodchucks to take shelter here.
In the New World the porcupines are represented by the members of the family Erethizontidae, or Coendidae, which have rooted molars, complete collar-bones.
As the drum revolves at a good speed, the silk is drawn by the steel teeth through the porcupines into the drum in more or less straight and parallel fibres.
Porcupines enjoy a very wide range, being represented throughout the warmer parts of the Old World, with the exception of Madagascar (and of course Australasia), by the Hystricidae, and in the New World by the Erethizontidae.