When I was still in the Philippines, I love the way how I woke up every morning. Birds would gather near our window and start singing. It is very pleasant to my ears. The beautiful part of it is that hearing another birds from a distant responding, too.
Birds sing because they have a syrinx instead of a larynx. The syrinx is the bird's voice box, an organ that lies deep in a bird's chest and is uniquely fashioned for song. That, at least, is the natural explanation for their gift.
But let me ask you, why do birds sing? Because their Creator put a song in their hearts. Each bird is "heaven's high and holy muse," created to draw our hearts up to our Creator. They are reminders that He has given us a song that we may sing His praise.
So when you hear God's little hymn-birds singing their hearts out, remember to sing your own song of thanksgiving, too. Lift up your voice to our Creator.
"Break forth in song, rejoice, and sing praises." Psalm 98:4 NKJV