Design a Face or something

Click on picture to see larger
I don't want their mess on my bench ...
 so I'm either going to "foam it", then place concrete over it then a piece of something until it dries -- If I can climb to it...

This is close-up -- which twigs should I remove? I'll have wait and see if I do anything

I didn't know if I should make a "hat" or an open mouth out of the hole -- any ideas?

.Hard to see through screen -- I believe they're black birds, -- bright orange beaks heck they're probably starlings (bird introduced to US because of Shakespeare works??) I know I won't be able to remove eggs, so I have to do it soon - rather than later...

    
 
   
I see a bird or a cat in this on the side view, but don't know if I can keep the look or not... it would be neat to make it look different from different views and to paint with glow paint - but man is that expensive ---

Couldn't wait until my knee was fixed and healed... so I "carefully" went up the ladder - the first step was a doosey. I filled it plastic bags, then foamed it. I did a rough job of placing a piece of rotten board over it. The birds really were watching me. The next morning they were rather upset. I hope they won't get stuck in the foam or try to remove it - it should me set. Then I'll cover it with concrete then maybe decorate it by making a tree face out of it??