We have a big purple martin bird house in our yard and most of the ‘apartments’ are occupied with nests. However, during our nest check (daily or every other day), we noticed some house sparrows trying to build nests in one of the apartments.  
 For those that don’t know about the house sparrow, they are invasive & will try to kill purple martin eggs/babies.  So every time we found a house sparrow nest, we removed it. However, a few times Mrs Sparrow apparently was in a hurry to build her nest to lay an egg.  Since we do not want any more house sparrows, we removed the nest & egg (if any).  Of course, being the crafty person I am, I saved the eggs for a craft project I had in mind. 
In a couple of the purple martin nests, there were some eggs that were unhatched (well after all the other eggs hatched). So we removed them.
The branches are off of our gardenia bush, and the dried flower bits are from our wildseed flower garden, I believe that they are the bodies of Bachleor Buttons.  I had these mini birds in my stash from YEARS ago & just came across them recently so … WAHLA… my mini bird egg wreath!   The whole thing measures about 5″.  I adhered some magnets to the back & put it on my fridge so we can look at it all the time!
bird egg wreath

bird egg wreath