Question
what can I do with birds that have been eating my kois?

Answer
Hi Josh,
Thanx for your question.  There isn't a whole lot you can do except I have heard some people put up 5 foot tall poles and attach streamers to them.  The constant motion of the streamers make birds nervous and not wanting to be vulnerable.  Also, if you have some dogs that you can keep in the yard, this will deter birds from landing around your pond.  I hope this helps.
Tom