Haiku vs. Senryu by Michael Dylan Welch- Haiku Master

The following is a "copy and paste" exerpt from "Graceguts" the website of Michael Dylan Welch.  Mr. Welch has thousands of acolades, publications and comments about Japanese poetry.  This quote has to do with the differences between Haiku and Senryu poetry.

  Haiku is a brief genre of poetry that typically captures a moment of sensory perception, often with a seasonal reference (kigo, or season word) and a two-part juxtapositional structure (equivalent to a kireji, or cutting word) that conveys or implies an emotion. Senryu, more accurately presented in English as senryu, with a macron) is similar to haiku except that it tends to be more satirical or ironic in tone, and does not need to include a season word or two-part structure (although some senryu may still include these elements yet still be considered a senryu). Some people think of haiku as focusing on nature, with senryu focusing on people, but this is misleading. The fact is that many haiku by the Japanese masters also focus on people, so having human content is not a distinguishing factor. Furthermore, haiku is actually a seasonal poem, not strictly a nature poem (many of the kigo that haiku aim at are in fact not nature-related), although nature often comes along for the ride. Instead, it is usually tone that differentiates haiku and senryu. Haiku tend to celebrate their subjects (even if dark), whereas senryu tend to have a “victim,” and may or may not be humourous. Haiku typically treat their subjects reverently, whereas senryu do so irreverently