Cat litter and birds

[cautionhot]

So I have a cat litter tray outside in a little court yard area. It's the only place cat will
go, cat is old and fussy. He likes to take his time and not have people around, doesn't like noise. He's grumpy and bossy quite frankly.

However lately pigeons have been coming into the court yard and they sit and eat the litter. Cat sits there and watches them

I'm worried that the birds are getting quite sick (why the hell do they want to eat cat pee and litter?). And also they're annoyingly and make a huge mess of the litter.

Any ideas on how to make them stop?

Use a covered litter tray

I'm not sure he could get in and out of one.

You can get low entry hooded litter trays. Or put something like garden bench over it and crap a towel over that.
I wonder if the pigeons are using the litter like hens use grit? (I know very little about birds)

@Bargebill19 that's an idea. I don't get it at all, they seem to love it. Even with cat shit in it!

Pigeons are flying dustbins imo!