Is it by your understanding that the hawk soars and spreads his wings toward the south? (Job 39:26 ESV)
Job was being asked by the Lord if he knew how and why the Hawk knows that it needs to go south for the winter. The Lord is smarter than we are and when He created the birds, He gave them instincts (knowledge) to do certain tasks. He put within the Hawks and other birds that migrate (travel to other areas) the knowledge of when and where to go.
Why do they migrate? There are various reasons why they travel, many great distances, for the winter or summer. The weather turns cold in the northern part of the world (northern hemisphere) in the winter and many birds cannot survive in really cold weather. In the summer, those birds go back north, because it gets cold down where they spent the winter. (The seasons are reversed in the northern and southern hemispheres.) So, some birds just keep going north and south each year so they can live in warm weather.
Other birds move around or migrate because their food supply ends and they go to the next area to be able to feed themselves. The Lord promised the birds and animals to provide for them, but He does not “spoon-feed” them. They have to go where He has provided for them.
And to all the animals on the earth and to every bird of the air and to everything that creeps on the ground–to everything in which there is the breath of life–I have given every green plant for food. And it was so. (Genesis 1:30 AMP)
A tree in Daniel has this promise given about it:
Its leaves were fair and its fruit abundant, and in it was food for all. The living creatures of the field found shade under it, and the birds of the sky dwelt in its branches; and all flesh was fed from it. (Daniel 4:12 AMP)
Look at the birds of the air; they neither sow nor reap nor gather into barns, and yet your heavenly Father keeps feeding them. Are you not worth much more than they? (Matthew 6:26 AMP)
Those are very good promises by the Lord, the Creator, that He will provide for them. That last verse also gives you and I the promise that He will also provide for us, because we are worth more. He loves us and has given us much more. See The Wordless Birds.
We will tell more things about the Hawks in other Bible Bird – Hawks articles.