African straw-colored fruit bats (Eidolon helvum) are able to fly greater distances than any other bat species. This enables them to successfully forage for food, while spreading seeds and pollen over wide-spread areas of Africa. (Photo : Flickr: Daniel Neal)
African straw-colored fruit bats (Eidolon helvum) are able to fly greater distances than any other bat species, a new study revealed. When competition for food sources increases and seasons change, the bats migrate further to reach ample hunting grounds. In doing so, the animals disperse seeds and pollen, which is vital for sustaining local ecosystems.
Researchers from the Max Planck Institute for Ornithology fitted African straw-colored bats with GPS-loggers to track the animals' flight patterns and discovered that the flyining mammel's traveling distances varied depending on season. The bats were more likely to fly further for food during the dry season than the wet season, according to a news release. Researchers suggest that these differences could be related to migratory behaviors in response to seasonal changes.
In order to better understand the relationship between seasonal population size and foraging behavior, researchers closely monitored the Accra colony of fruit bats. During the wet season, researchers found that most bats left Accra and migrated to northern savannas. However, some individuals were left behind and the colony inevitably became smaller. Therefore, there was less competition for food during this time. On the other hand, populations increased during the dry season and there was a much greater competition for food, according to the release.
Straw-colored fruit bats are one of the most common bat species found in Africa. Generally, the bats are found hanging upside down in the crowns of old mahogany trees during the day. But when nighttime rolls around, the mammals quickly blanket the sky in search for food. The animals have a wingspan of up to 80 centimeters and can travel upwards of 180 kilometers per night during the dry season, the researchers explained in their study.
Researchers also discovered that the bats' diet changed in response to seasonal variations. During the dry season, the bats mainly feed on nectar; however, they prefer to forage for nearby fruits during the wet season when there is less competition.
"The fruit available during the dry season may not be sufficient to feed all of the animals. It is also possible that they need certain nutrients during this season and for this reason prefer to feed on nectar," Jakob Fahr, study leader, explained.
After discovering the bats were record-holding travelers and could fly up to 90 kilometers when migrating, which is the greatest travel distance recorded for any known bat species, researchers were interested in how this affected local environments. They found that the bats transport seeds and pollen throughout different areas and act as "Gardeners of the African Forests." Conveniently, the bats even fly over forests that are threatened by deforestation and human land use.
"For this reason, fruit bats should not be primarily associated with infectious diseases. They fulfill important ecological roles, without which Africa's ecosystems would disappear," Fahr added.
Their findings were recently published in the journal PLOS ONE.
- African Straw-Colored Fruit Bats are Record-Breaking Flyers and Continental Gardeners, Researchers Say