During puberty: After infancy, the tween and teen years are the period of most rapid change. For girls, the growth spurt begins between 10 and 11 and lasts until around 15; for boys, it starts about two years later and lasts until age 17 or so. Girls typically stop growing about three years after they've had their first period, but boys continue to grow throughout their teens.
Parrots have thick tongues, so they don't need lips to approximate human sounds. The tongue's thickness, and where a parrot positions it in his mouth, allows him to imitate human speech. When air passes through the syrinx, the parrot moves his tongue to produce sound in his throat and mouth.
Parrots are not songbirds, even though they can be taught to sing human songs. 1  A favorite songbird, the European robin. 2  The crow of the rooster is a familiar bird call. 3  The pied currawong, an outstanding singer. 4  The jackdaws helped Lorenz to understand bird communication.