What did Bagheera do in spring which surprised Mowgli?

Bagheera tells Mowgli that it is time for him to leave.... that the jungle is no longer to be his home.

“No, Little Brother. That is only tears such as men use,” said Bagheera. “Now I know thou art a man, and a man’s cub no longer. The jungle is shut indeed to thee henceforward. Let them fall, Mowgli. They are only tears.”