Kim Newman's stories as being too arch or knowing!
A later clip. Presumably 1969 or 1970 since in colour. This is the theme tune I remember, though not usually played by Wally Wombat on his recorder!
Bizarrely, Aunty Jean seems to have aged far more than 7 years between the two. Working with koalas must be stressful.
(and some outside footage, sound lost, the comments suggest that Aunty Jean was there at the opening day of the zoo. Note ostrich in plane!)