There’s a small plum tree outside my office window, on  the opposite side of our garden wall. It’s still lush considering the season, a blaze of bright yellow leaves almost the same hue as the long-gone fruit the tree bears in summer.

Over the past few days, the weather reports for the area have had bright suns happily shining down over Geneva, and I have no doubt that’s accurate once you get above the fog line, located at least 100 feet above our house. It’s misty, quiet, pale autumn weather. No wind.

So it was a shock to find the plum tree quivering and shaking in what seemed to be a highly localized little storm. Even the hedge right next to it was unaffected. It was just the tree, branches bobbing and jerking, leaves falling in a rain.

It took me a moment to register that it was that tree, and only that tree, caught in a vortex. All the other trees were still, their remaining brown leaves hanging quietly, gathering fog.

So I looked more closely. And it turned out that the wind source was a small swarm of birds. Not sparrows, and not all the same. Tiny redbreasted things, a few yellow-breasted, some a sort of grey-brown. I should know their names but I don’t.

There were 20-30 of them, and they were each landing on a branch, then inching up step by step, plucking out leaves as they went along and then dropping them. I thought maybe they were hunting for insects, but no. They were just tweezing the tree of its leaves. When a bird got to the top of a branch, it would flutter and move to another branch. I’ve never seen the birds do that before, and they didn’t do it today.

I went out this morning and raked up the rich circle of gold beneath the tree – if they start up again, I’ll have evidence, even if I miss the tweezing itself.