The quetzal was important for the Mayas and the Aztecs. Both cultures worshiped a god with the name Quetzalcoatl (also called Kukulcan). This god was wearing a hairdress of quetzal feathers.
Wearing quetzal feathers was only allowed to priests. The feathers are said to be taken from living birds. The birds were then released to grow new feathers.
The quetzal became a symbol of freedom for the indigenous people in the time that the Spanish conquered Central America. In Guatemala this is nowadays still reflected, the quetzal is the national bird of Guatemala, the national currency is called "quetzal", and the quetzal is pictured on the flag.
The quetzal symbolizes many things as becomes clear from this poem:
the original source of this text is unknown to me.
I found it inThor Janson, In the land of Green Lightning
Symbol of Freedom
Another story explains how the quetzal got its red breast in the struggle for freedom and independency::
In 1524, when the Spanish conquistador Pedro de Alvarado defeated the Mayan chieftain Tecun Uman, a gilt-and-green quetzal alighted on the Indian's chest at the moment he fell mortally wounded; when the bird took off again, his breast was stained with the brilliant crimson blood of the Mayan.
(quoted from: Costa Rica Handbook by Christopher Baker)