Yes, I give the birds thread clippings (get LOTS from machine embroidery!) & dryer fluff. Some bird species seem to prefer one thread color or fluff over another. I like to think that if I'm not personally recycling, then the birds get to. It's interesting to see the old nests that get blown down how many have colorful threads & fluff in them -- I leave them out, as they pick thru them again. It breaks my heart when I see broken shells though.