What has been the biggest cause of biodiversity loss? * 0 habitat destruction
O Animals being kept at the zoo for research
O legal hunting of animals
Humans keeping animals as pets

Habitat destruction is the key one out of all of these. Animals being kept at the zoo for research are usually endangered or vulnerable species which is doing more good than harm to them. Legal hunting of animals is most likely for rabbits, deer, and a stabilized population in the wild. Habitat destruction can destroy many populations and cause loads of damage. An example of that would be the Australian wildfires at the start of 2020.

The answer is observations and interpreting.