Fairy-wrens often have other birds laying eggs in their nests (a brood parasite). They have adapted by singing a special tune to their eggs. Once hatched, those that sing the password get food while any brood parasite chicks go hungry. – WTF Fun Facts
singing
WTF Fun Fact – Sunrise Song
Gibbons start each day by singing at sunrise. Their vocalizations are often referred to as ‘song’ because of the way they modulate their pitch as well as singing with others in ‘duets.’ – WTF Fun Facts
Source: https://wildambience.com/wildlife-sounds/white-handed-gibbon/
singing is a skill learned not something you are born
Singing is a skill learned, not something you are born with – WTF fun facts
