One of the first Nat.His. books I ever read, at a very young age and it definately fired my enthusiasm too. I no longer have a copy but I remember much of it was about the colony of Jackdaws in his native village(was it Altenburg?) And the behaviour of the local Dogs also.
I do have his last(?)work though- entitled 'I am here, where are you'? -a study of Greylag Geese.
I recently reread my copy, inspired by seeing the water shrews at Slimbridge, it's still surprisingly good. He established the jackdaw colony which is the heart of the book - but many other species are mentioned. I have read his book on dogs (now superseded by modern research) and 'On Aggression', but not the goose book.
Alan