The video clip in the link below was put together using footage taken during the 2013 breeding season - you'll need to scroll to the bottom of the page.
The pair of owls are still there and have bred again this year, rearing a further six young.
http://www.rspb.org.uk/discoverandenjoynature/seenature/reserves/guide/b/beckinghammarshes/ourwork.aspx