Bird identification help

Hello. 
What bird sounds just like a Ringneck Parakeet but isn’t?

Seen and heard flying High over Studland on the evening of 10th Aug in a NE direction.

Not sure if it flew in off the sea or was travelling along coast.

Dumpy, short winged, rapid wingbeats, small Woodpigeon in size. Any ideas gratefully received. Thanks. Jon.