The Secret of the Island by Jules Verne

It was now two years and a half since the castaways from the balloon had been thrown on Lincoln Island, and during that period there had been no communication between them and their fellow-creatures. Once the reporter had attempted to communicate with the inhabited world by confiding to a bird a letter which contained the secret of their situation, but that was a chance on which it was impossible to reckon seriously. Ayrton, alone, under the circumstances which have been related, had come to join the little colony.