'Francine Porad of Seattle, Washington and past President of the Haiku Society of America says, "There are some people who believe any reference to human beings in a haiku turns the poem into a senryu. I disagree. In my opinion there should be no separation, is no separation between human nature and the world of nature." '
-- Elizabeth St Jacques,
"Haiku or Senryu? How To Tell the Difference" (I'd never heard of senryu before today. Now I wonder if there is a past President of the Senryu Society of America. Google doesn't think so, alas.)