Adaptive Value

Why do bats practice folivory?

Fruit bats may be eating leaves to make up for the low amount of protein and other nutrients in fruits (2). Insects are high in protein, but since fruit bats do not echolocate, they must find alternate means (2). Even for those bats that can capture insects, the protein yield per unit of energy put into foraging is greater for plants than insects in some cases (1). Also, instead of consuming large amounts of low-protein fruit, fruit bats can eat a smaller amount of protein-rich leaves (1). For pregnant or lactating females, protein is even more important (2).


Baby fruit bats from Australia require much energy input from their mothers (19).

 

 

 

 

 

 

It has also been hypothesized that male bats practice folivory because it takes less time to find and eat leaves than fruit or insects, so they spend less time away from protecting their harem (1).

 

Another hypothesis for why bats consume leaves is that leaves provide compounds that are needed for hormone synthesis (1). In addition, certain leaves may provide protection against parasitic infection and illness (2). However, more research needs to be done on the hormonal and pharmacological influences of plant compounds in bats.

A fruit bat shown investigating some leaves in the image to the right (18).

The adaptive value of folivory may be a limiting factor, since folivory requires a slightly more elaborate digestive system, which would add weight and take energy away from a bat's ability to fly. However, folivory doesn't seem to require much additional gut development, so folivory would serve as an easy way to provide the bat with additional energy without taking away from its ability to fly.