Bats and Plants

by Vanessa Rojas

The role of bats within tropical forests is one that is both irreplaceable and crucial to these unique and diverse ecosystems.  The meticulous relationship between bats and plants is not fully understood, however scientists are often gaining new and important information. Tatyana A. Lobova, Cullen K. Geiselman, and Scott A. Mori have gone to great lengths combining decades of previous research, along with their new findings, to help us understand the importance of bats in their book, Seed Dispersal by Bats in the Neotropics.

Neotropics refers to the New World region, south of the Tropic of Cancer, including southern Mexico, Central and South Americas and the West Indies.  In 1999, in-depth field research on plant dispersal by bats began in Central French Guiana.  These findings were then also used to infer further understandings of the bat and plant relationships found throughout the Neotropics. 

To give an idea of the importance of this relationship, of the 1,116 bats known to date, 29% depend partially or entirely on plants as a food source. However, this is a co-dependent relationship because at least 858 plant species in the Neotropics depend on bats for the survival of their species through pollination or seed dispersal.  Bats make up a majority of mammals, totaling at 105 of the 191 known mammalian species in French Guiana. Of the 105 bat species, 37% are fruit eating bats.  Within the study region of Central French Guiana, it was found that 15% of the native flowering plants are bat dispersed or show bat dispersing potential.  These data and previous findings were used to approximate that 549 plants in the Neotropics display fruits that are consumed by bats, most often resulting in seed dispersal.

Bats are efficient at dispersing quality seeds due to a few key characteristics:     

  1. Selective eating habits of only ripe fruits which contain mature seeds,
  2. Flying away from parent tree with fruits,
  3. Defecation of seeds over open areas suitable for germination, and
  4. Seeds are very rarely damaged during handling or digesting.

The plant-bat relationship goes beyond just that, it is also crucial to the ecosystem as a whole.  This relationship is important for forest regeneration in slash-and-burn (cutting and burning of forests to create fields) areas.  In one region where slash-and-burn agriculture techniques were abandoned for three years, 87% (8,280 out of 9,320) of the stems present were plant species that depend on bat and bird dispersal.  Although secondary forests lack much of the biodiversity found in primary tropical forests, without bats, growth of these destroyed regions would be deficient.

Meet Neotropical bats at the Bat Zone! 

Jamaican Leaf-nosed and Short-tailed Fruit bats help disperse seeds throughout the rainforest by eating up to twice their individual weight in fruit, spreading thousands of seeds every night.  These bats and others like them aid in the regeneration of rainforests. 

© 2012 Organization for Bat Conservation