From The New York Times:
In Kenya, a 10-year-old elephant named Mlaika seems to think she’s a truck. At least she has been heard imitating the low rumble that trucks make on a nearby highway.
Mlaika’s mimicry is described in the journal Nature, along with a report of an African elephant that lived in a Swiss zoo with Asian elephants and learned to imitate the chirping that only the Asian species makes.
The two findings show for the first time that elephants – like primates, birds, bats and some marine mammals – are capable of vocal learning. The discovery has important implications for understanding how elephants communicate.
Audio clip of elephant sounding like truck (sort of).