Fledgling blackbird


We have a fledgling blackbird near our oil tank.  Unfortunately we also have a cat .. 

I discovered it 2 days ago when a pair of blackbirds got extremely agitated in our garden when the cat was out . The fledgling did fly a short distance from the ground into a hedge . The mother is visiting often and I’ve kept the cat inside since . I can see the fledgling still on the ground and it looks healthy. 

I am wondering how long I need to keep our cat inside ? Will the bird stay around the garden even when it can fly ? I’m assuming that there is a nest nearby but I’m not sure . Our next door neighbour just last week cut down all hedging in his back garden- there hasn’t even a blade of grass left .. so the nest may have been there .