Dumbo not only can fly, he can also tell the difference between languages. According to a report in the Proceedings of the National Academy of Sciences, African elephants can distinguish between different types of human speech and move away from threatening people. Researchers played recordings of the voices of Maasai men, who have been known to kill elephants over water access and grazing space. When elephants heard adult Maasai voices, they tended to gather and carefully move away. When they heard the voices of Kamba men, or Maasai females and children, all of whom rarely pose any danger to elephants, they showed no concern.