Welcome to BB! It’s great to see you are using the forums to ask questions about your rabbit’s health and behaviors. Owning a pet rabbit and ensuring his/her health and happiness is an ongoing, learning process, and it helps to have other’s experiences in mind.
When I hear fur loss, I think of the same, usual suspects:
1) Another rabbit pulling fur out – I believe Mango is your only rabbit, so this doesn’t seem plausible.
2) Heavy molting – Some rabbits do shed in patches, leaving bald spots. The skin exposed should look healthy.
3) Mites – Usually accompanied by white flecks (I believe)
4) Ringworm/fungal infections – the bald spot grows outward and flakes/crustiness is produced
How does the exposed skin look?
The answers provided in this discussion are for general guideline purposes only. The information is not intended to diagnose or treat your pet. Seek the advice of your veterinarian or a qualified behaviorist.