At Oso Bay
can change in an instant:
a heron preens its feathers
in the light of home . . .
Corpus Christi, Texas—named "America's Birdiest City" for 10 straight years.
—Ribbons, Spring/Summer 2013
Tanka sequences: It's generally accepted that each unit in a sequence of tanka should be able to stand alone reasonably well; in other words, it should make reasonable sense if extracted from the sequence and read by itself. So, the various tanka in a sequence don't function in quite the same way as verses do in a longer (for example, free verse) poem.
English-language tankaists continue to explore sequences. I tend to think of sequences as involving progression or development and using links, even if subtle, from one tanka to the next. Readers might be interested in checking out an article by M. Kei on sets (a generic term for groupings of tanka, including loosely organized ones) and sequences in the recent Fall issue of Ribbons, the Tanka Society of America's journal.