Country diary: a frail creature needs my help. But what is it?

Nests have been collapsing from beneath the house gables in recent weeks. Wind and rain have helped; sun and unseasonal warmth then baked the nests’ remnants to the walls. On a day of the latter, I see the thing. From an upstairs window, caught on the guttering. It’s moving: persistently, pitifully, a small round head bobbing in and out.

From 10ft away, it looks in a hell of a state. I see a frail wing, between gutter and slate, and immediately think bat: then I see a splay of feather, and think bird. A baby, caught in the fragments of a nest that’s fallen? Unlikely, given the month. I watch it for ages, grimly, trying to work it out.

It’s the movement that’s the most troubling. Desperate, but constant – with that unmistakable, muscle-driven writhing of something. Of life. Obviously I must go down there, do something for it.

I do, with a net my kids used for rockpooling, a paper bag, my phone and – sickeningly – a brick, hoping not to need it. I’m hopeless with comforting injured animals, or ending the pain of ones beyond help. The former, I’ve done a few times, the latter only once – at speed, behind the wheel of a car.

Whatever was in the gutter, it would be grim. I consider leaving it, letting nature – or a cat – do their work. But I can’t shirk its suffering for my own sake.

I arrive beneath it, and stare, disbelieving. It’s dangling moss, trapped with a feather. At the guttering is a wedged twig that, as it sways, pushes a piece of moss outward and makes it look uncanny.

The movement – that basal trigger to hunters, saviours, observers – of something alive. I’ve been fooled before by leaves suspended by spiderwebs, moving gyroscopically in the breeze. But never so convincingly.

I feel stupid. Amazed. But more than anything, relieved. I knock on the window and shout to my wife, “It wasn’t alive, it was just moss”, and throw her a thumbs-up. She returns the gesture, though with a strange expression. She doesn’t have a clue what I’m talking about.

• Country Diary is on Twitter at @gdncountrydiary