Not your average fused glass posting but something I have done for a few years now. I have 2 beautiful Persian cats that come Spring time, even though indoor only cats, they shed like there is no tomorrow!
Each time I comb them I have the equivalent of another cat but instead of just throwing their fur in the bin but I collect it and put it out in the trees and bushes for the birds. Valentine in particular has ultra fine fur, like wool which makes him a nightmare to groom as he gets so knotty but is wonderfully soft.

I love watching the birds come and pick bits to 'feather' their nests and the predator becomes a source of warmth! Not only have I watched birds collect the fur but when we cleaned out the Blue Tit box in Autumn there was Valentine fur in there!
It's locally grown and harvested from a renewable resource and supplied in biodegradable packaging thus leaving no carbon footprint.

I also shed a lot! All year round, in fact, much to my husbands annoyance! However in Spring I put my hair out with the cat fur!

Admittedly not as soft and cosy as cat fur but I would imagine there are structural uses such as holding a nest together!
As this year has been a particularly cold and wet one I thought that soggy cat fur wouldn't be unlikely to impress Mrs Bird so I have come up with this idea

I hope it works - I will try and get a snapshot!