Egg Thieves!

A long time between posts - mainly due to a neck problem (2 herniated disks, C5/6 & C6/7) which limits my stamina (due to pain) at the computer. Plus my computer is playing up recently (I'm using SMD's work laptop to do this), and I can't sit at the computer long enough to sort it out.

Anyway - when I get a chance I'll put up some photos of a friend's wonderful garden in Stanthorpe.

But for now - I need some help.

Does anyone have a suggestion to stop crows stealing our eggs?
 
We started loosing eggs, then found the occasionaly broken, but completely clean shell.  Very puzzled at first, until we saw the crows going in & out of the tractor.
Unfortunately Elsa & Blacky don't always lay their eggs before we leave in the morning.  So the crows have all day to find them.

Hope someone can help.
Ravs