Cattle Dung:
a rewilding indicator 

If there is a thing that crystallises conflicts amongst Lantau residents, it is as simple as a cattle dung. 
[...]
As we observe the cows roaming freely on Mui Wo roads, hear residents and janitors talking of them like of old neighbours, see beautiful landscapes thriving peacefully, we realise Lantau residents are engaged in a large-scale ‘rewilding’ experiment...