Blue tit fledged too early? Please help

Hello,

as I’ve gone to let my dog in the garden I’ve noticed on one of our little tables right outside our back door a little blue tit. We have a cat next door and I’m worried he will get to it. I’ve not intervened as I’m hoping it’s mum may come and feed him but he’s not moved in ages. 

is there anything I should do or should I leave him alone and let nature take its course? He’s so cute and I hate the thought that he’s cold or hungry.

any advice would be appreciated.

thank you!

Eleanor