What Do I Do?

Alright here is the situation!
Last night I found a healthy bird in my pool under a plank I left in there so some kittens could crawl out.

Now this bird is full grown, doesn't appear to have a broken wing or broken leg or anything like that. The bird isn't favoring any thing or appear to be damaged in any way.

But it won't fly.

I kept it in a cage last night in the house and gave it some seeds and water...well not really seeds. I scraped some whole grains off the top of a loaf of bread but it is as close to getting it something to eat as I could.

I thought maybe the bird had been overcome with the heat from yesterday and just couldn't fly out of the relatively shallow empty pool for some reason. So I picked it up and brought it inside to cool it off. Now it is the next morning and he still won't fly away.

It will barely walk but he seems content to just sit there and look around. It is cool outside right now and there are a lot of birds in my yard so I'm going to leave it out there and hope it gets the idea and has the Disney ending and flys home!