Watership Down is novel by Richard Adams in which a warren of Berkshire rabbits flee the destruction of their home by a land developer.
When asked "What gift from your father do you remember or cherish the most?" Zak Nilsson, Harry's oldest son, replied, "I think that would have to be a copy of Watership Down he bought for me at an airport. He drew a little picture of a bunny and wrote me a note on the inside cover; it has a lot of sentimental value."
Beckley originally wrote "Watership Down" for an animated film version of Richard Adams's novel. Beckley based the lyrics on the book, but didn't want to give too much away as it was played at the beginning of the film. "So I had long, protracted evenings with my friend Harry Nilsson about it, 'cause he loved the book. He'd say, 'Play it again; that line's OK.' And piece by piece, he kind of pulled the song apart. Finally he said, 'I think the problem with the song is the title.'"