What is an animal-animal amensalism?

Answer 1

Exactly what it describes I guess.
One animal species threatens the very existence of another through it's biological characteristics.
I think a good example would be the introduction of a new species into an environment where the indigenous species has no defense against it.

Answer 2

"Amensalism is a biological interaction between two species in which one impedes or restricts the success of the other without being affected positively or negatively by the presence of the other. It is a type of symbiosis. Usually this occurs when one organism exudes a chemical compound as part of its normal metabolism that is detrimental to another organism.
The bread mold Penicillium is a common example of this; penicillium secrete penicillin, a chemical that kills bacteria. A second example is the black walnut tree (Juglans nigra), which secrete juglone, a chemical that harms or kills some species of neighboring plants, from its roots.
Antibiosis or allelopathy also explain similar interactions."