Entendre entre les branches

13:03 Nov 8, 2020 

It could be because of the difference in implication (or nuances) that the two phrases suggest. "Grapevine" is used to suggest many people have been talking about something (or information that has passed along), and "a little bird" implies that someone has directly passed on the information.
You can't ignore the general usage and implication of a phrase simply to match words literally, otherwise the tranaslation would not be 100% accurate.

23:54 Nov 6, 2020 

Little birds sit in branches
Grapevines also have branches

08:35 Oct 30, 2020 

The little bird solution would indeed be closer to your explanation of the meaning. Do you have any more context?

05:38 Oct 30, 2020 

My research suggests "hear something on the grapevine", but that would mean Claudia's explanation is incorrect. I'm going to wait for the context.

02:51 Oct 30, 2020 

I thought of this and then saw Phi's comment so yes, please do put it up Phil as it is not quite the same thing as "I heard it through the grapevine".

19:36 Oct 29, 2020 

Yes, that's a good idea of Phil. More context might shed a new light.

18:46 Oct 29, 2020 

It sounds like "a little bird told me" or "I heard it on the grapevine", but could we have the context, please.