According to Vance when he wrote the introduction to Morreion (MSF meulenhoff, 1978) he wrote “Alfred’s Ark” mostly to entertain himself and meant it as a comment on the shortcomings of humanity. He admits that the story is not SF or Fantasy—or even a regular short story, but was pleased to have it published. He also asserts that it was first published by New Directions, but I haven’t been able to confirm that.
Republished in The Moon Moth and Other Stories, Spatterlight, 2012.