Explanation:
Bali is a region in Indonesia. New Guinea is found in the Oceania and it is home to the largest Islands in the world.
New Guinea have more bird species than Bali because of more ecological space available to these avian animals.
With more space available for a specie comes the ability to improve diversity.
Bali has a lot of human control and need for available space. The ecological space available to attain diversity is therefore very limited.