Love that phrase over the first two lines. I guess the last line is both 'literal' as Fall takes over from Summer, and that this is the last day of September, as it leaves, and October takes over.
As September is my birthday month and wedding anniversary, it's sad to see it go, but still enjoying presents into October, just like your leaves, and 'leaving'.
This was an unexpected treat as the European Robin, I realised, was privately giving a sub-song, not quite the same as whisper song, that you might be more familiar with?
As I'd already written a sub-song haiku (with the British Blackbird) I left that out, but some UK birders might guess. :-)
this small ache and all the rain too robinsong
First publication credit: Modern Haiku vol. 44.1 winter/ spring 2013
Anthology credit: naad anunaad: an anthology of contemporary international haiku ed. Shloka Shankar, Sanjuktaa Asopa, Kala Ramesh, India, 2016