Nest? Virus?

Inspired by several entries recently to "look up", that is what I did today.

I like the tangle of lines here, and the contrast of the trees with hardly any leaves and the hint of autumn fading in the background.

The nests have lost their protection - I wonder if they are still in use?

Later edit - having read the comments below, I had to change my title. Always learning, even on Blipfoto.