Adam Clarke on Psalms 104:17

Where the birds make their nests - צפרים tsipporim signifies swallows, sparrows, and small birds in general; here opposed to the חסידה chasidah or stork. Perhaps the heron may be understood, which is said to be the first of all birds to build her nest, and she builds it on the very highest trees. The general meaning is, that God has provided shelter and support for the greatest and smallest birds; they are all objects of his providential regard.