The Wallace Line is a faunal boundary line drawn in 1859 by the British naturalist Alfred Russel Wallace that separates the ecozones of Asia and Wallacea, a transitional zone between Asia and Australia. The line runs through the Lombok Strait between Bali and Lombok. The distance between Bali and Lombok is about 22 miles and many bird species observe the line as most birds don’t cross open ocean water. One bat that observes this line is the Blue Bat of Bali, which has no equivalent on Lombok. The Blue Bat is about eighteen inches high and has a wingspan of two feet.

The Blue Bat is unique because it flies around during the day and the blue colour provides some camouflage against the tropical skies. The bat is primarily a fruit-eater and uses eyesight and echolocation to land on the fruit trees. However, this bat is best known for eating the fruit left behind by Hindus taking part in religious festivals on Bali. Every aspect of Balinese life is steeped in religious belief. Ninety per cent of Balinese are Hindu and around five per cent Muslim (these percentages are reversed on Lombok, which might be why the Blue Bat isn’t found on Lombok).

There are festivals almost every day on Bali and the Blue Bat makes sure it finds them. The availability of such large amounts of food might be why this bat flies around during the day and rests at night. The Blue Bat doesn’t swoop down and take the fruit during the festival, but waits until the ceremonies are over before starting to eat.

Extract from Animals Evolution Forgot