... then it should be able to sustain itself.  

If it can't sustain itself, it should close.  Just like a store or a business that doesn't get enough business to stay open... or can't seem to make enough money to keep the doors open.  

Why should we be maintaining a zoo that not-enough-people are going to?  Why should we be maintaining a zoo that donors are running away from?  Heck, they plaster the Detroit Mayor's name on the thing, and they don't/can't contribute much to the place.  It resides in Royal Oak.

I'm glad they're open to putting it up for a public vote.  It gives the public a chance to tax itself, through a direct vote.  But it was sad to hear L.Brooksy talk about how "it's only $10 for a house valued at $200k".  Oddly enough, going to the zoo costs $10.  So Oakland County wants the homeowners to pay for the Detroit Zoo, by forcing them to buy a yearly admission ticket for every home.