Endemism
Endemism is the state of a species being native to a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsewhere.
Explanation:
Endemic species are those that are found in just one region and nowhere else in the world. For example, kangaroos are originally endemic to Australia and are found nowhere else in the world. ... The Tasmanian Tiger is one such animal that was endemic to Australia, Tasmania and New Guinea. But now, it is extinct.
It can be observed and tested
Night vision because the creature will be able to hunt food in the night, having enhanced eye sight. To continue, light colored fur would make the creature stand out taking away cover and the other answers have no benefit to the scavenger.
Aerobic respiration to lactic acid fermentation, lactic acid is the reason your muscles get sore after a workout
Hope this helps.