What impact do the dead sparrows have on Cole in Chapter 10?

In watching the gray sparrow hopping amidst the branches of the tree, Cole realized that the baby birds might just have someone looking for them.... worried about them. He also realized that no one was looking for him.

He watched one solitary gray sparrow hopping among the broken branches near the nest. Was that the mother? Was she looking for her young? Cole licked his cracked and dried lips. At least the babies had a mother to search for them. Nobody, not even a scrawny gray bird, was looking for him.