Symbiosis between Zebra Finches and emus (1 Viewer)

Dear,

I’m French and need your help.
I’m looking for informations about the symbiosis between Zebra Finches and emus.
I would like to know what do the emus bring to the Zebra Finches
(in return of the Zebra Finches alert of other/human presences), because usually each animal brings something to the other in case of symbiosis.

Please find hereunder an excerpt from the book Boom and Bust from Libby Robin :

"Being human persons, it is easy to see how tellers communicate and humans take notice. But it is not only humans who pay attention. In the Victoria River country, the emu is associated with a little finch. Finches stay close to water and their alert and nervy action tells of other presences. When emus comes in for water, they stop to listen, and if the little birds are not calling out, they know they should stay away because there are people there. When the emu drinks, the little finches warn if somebody is coming."
Diamant mandarin - Taeniopygia guttata - Zebra Finch

In advance, I thank very much anyone who accepts to answer me.

Well, this is the first time I hear this, but I guess emu brings nothing and it is not a symbiosis at all, just smart use of ornithology skills on emu's part.
I am not sure why finches would be scared of people at all; most small passerines I know treat humans the same way they would treat herbivores.