Anticipate with great apprehension of fear.
The caged bird singswith a joyous songof the captive life that kept it safe all along.This answer exemplifies the two birds: free and caged. Free in such a way that it is able to sing a song of its choice, and caged, because even if it is in captive it has something to be thankful for, its safety.
Farther for physical distance and further for metaphorical or figurative distance.
Answer: The main idea is about humans relying on animals/pets and vise versa.
