Complex sentence: In the mid- 20th century the Japanese serow was hunted to near-extinction; in 1955 the Japanese government passed a law designating it a "Special National Monument" to protect it from poachers.
Split into simpler sentences: In the mid- 20th century the Japanese serow was hunted to near-extinction. In 1955 the Japanese government passed a law designating it a "Special National Monument" to protect it from poachers.