The verse is about the transitoriness of life. The hounds are about the business of being hounds, hunting; the greiving widow has already taken another lover while the body, though out of sight is certainly not hidden, yet it is undiscovered by all but the twa corbies who have not one whit of sentimentality under their feathers. They will thatch their nest with his hair and pluck out his bonnie blue e'en (eyes) for a tasty tidbit. To complete the utter desolation of a forgotten life of a nobleman, the cold wind blows forevermare over his white hausbane (bleached bones). A child's song? Perhaps.