Because of the rapidly growing population, deforestation and natural calamities.
What do you think will happen to animals and humans if the amount of oxygen in the air is reduced?
Over 10,000. But this can be reduced if we all DON'T abuse animals
Animals breathe oxygen and eat plants.
Calcium
Animals that would have survived on reduced light would be those that are meat eaters. Of course, they wouldn't have survived long because plants would dies and they wouldn't have oxygen.
Reduced oxidative stress
The most well known are rhino and elephant
The scientific term for animals that live underground is "subterranean fauna." These animals have adapted to living in underground environments, often with specialized features such as reduced eyesight or elongated bodies.
hunting them or damaging their habitat,both can lead to reduced numbers
by reducing the amount of tree eating animals through predation, wolves = reduced amount of tree eating animals = less trees eaten = more trees
The blind mole rat has a thin layer of skin covering its eyes, which is considered to be vestigial. There are also cavefish which have eyes that are vestigial. (There are also other vestigial traits in other animals that do not burrow.)
The epipelagic zone is uppermost part of the oceanic zone to allow for photosynthesis. Animals and life in this region must adapt to lower levels of sunlight and reduced oxygen use.