Genesis 1:21-22

So God created the large sea- creatures and every living creature that moves and swarms in the water, according to their kinds. He also created every winged bird according to its kind. And God saw that it was good. 22 So God blessed them, “Be fruitful, multiply, and fill the waters of the seas, and let the birds multiply on the earth.”

So God blessed them. When God blesses, it is a blessing indeed.  One wonders how quickly the birds multiplied under a perfect world in which there was no death and destruction, and birds would have no natural enemies.  We don’t know the answer to that, we do know that birds multiplied after the flood in a profusion of types, sizes, and shapes, and this was after sin and death had entered into the world.  What must it have been like before?