Protecting my nuts

Well one nut.

One precious nut!

a precious walnut

This tree managed to set two nuts a couple of years ago (link), but they didn't ripen well. I'm suspecting that this year will be no better, but given a good autumn there is a chance that this nut could ripen. I'm wondering whether the wildlife will get it and what I can do to protect it.

Jay asked what my most likely nut swipers are here and I guess I'm not sure! Would the strategy be different for different critters? At the moment I'm thinking birds are the most likely - crows probably. Mice maybe. I'm lucky we don't have squirrels on Skye. What other animals like to eat nuts? The other possibility is that the weather could knock it off the tree before it is ripe - towards the end of September we often get quite a few storms, but I guess I can't control the weather!
At the moment the walnut tree is pretty small and one nut might be possible to protect - what about when (in my dreams) I have a large tree full of walnuts? This will be a more tempting target and also more difficult to protect.

What would you do? What strategies can I use now and in the future to try and get a walnut crop?

Squirrels are relentless with walnuts, honestly. With just the one nut it might be worth trying a mesh bag over it while it's still on the tree, not foolproof but it at least makes it harder for them to grab and run. Jays in my experience tend to go for things once they've dropped rather than stripping them off the branch, so keeping it bagged until it's ready to pick might help.