I was certainly noticing more seasonal changes before this current cold spell, the most noticeable being a general increase in insect and reptile activity, particularly geckos and whatever those enormous, house-dwelling spiders are. I'm curious to see if our 'house' will be infested with those horned lizards when the warm weather hits because I found some fairly large eggs a few months ago. They're not snake eggs. I'm sure of that because I picked one up, wondering what it was, and after I mistakenly broke it a little creature jumped out and looked around in a dumbfounded manner. He definitely wasn't a gecko. He was either one of the smallish horned, dinosaur guys or one of the long (they get well over a foot here) striped fellows.
Regardless, here's a rundown from this neck of the woods on your observations:
1. large brown hornets reappeared (the ones that don't seem to be dangerous) plus the odd tu fong and hu tou fong
I'm not sure if this is the type we've been seeing or not. At least one type has reappeared here, and it's the same guy coming back every day. He hides out on the outside of our house.
2. started seeing (dead) snakes on the road up to my place
We saw a few of those over the winter, but we've seen no snakes, dead or alive, for a few weeks. I almost think one of not-our dogs got bitten by a non-poisonous snake recently though.
3. first lightning (though way up the north coast)
Yea, that was cool.
4. green Japanese pigeons have returned
Nope, haven't seen those, but we are hearing the nightjars more now, though I don't think that's a seasonal thing.
5. bamboo chicken has started calling again
I'm not even sure what they sound like.
6. common deciduous trees blossoming (light purple flower)
I think that's called a 'ku3 ling2'. They're beautiful, and I was told recently that some Taiwanese don't like to plant them because their name sounds too much like 'ke3 lian2'.
7. occasional southerly - though dong bei ji is still the prevalent wind
I'm absolutely blown away, pun entirely intended, by these changing winds. It's something I just never experienced on the west coast. I can literally see the winds shift from south to north or visa versa in the course of thirty minutes. Amazing.