Answer:
Birds and leopard
Explanation:
It has been researched and discovered that the feces of birds and animals can be used to determine the state of health of an ecosystem.
For example, it has been discovered that hormones and other substances are excreted through urine and feces. And researchers have discovered from the feces of leopards, that a leopard that has cave or trees where it can hide from hunters are not likely to be stressed out like the one that does not have.
