Kate Ravilious, National Geographic News 21 Jul 08;
More than a hundred bat species have been found packed into about five acres (two hectares) of Ecuadorian rain forest.
While the species found are not new, the diverse mélange—in Tiputini Biodiversity Station in the eastern part of the country—marks the highest number of bat species ever recorded in one place, researchers report.
Tropical rain forests such as Tiputini offer bats a plentiful menu.
Some of the flying mammals—munch on frogs, insects, fruit, and nectar. Others have a taste for fish. And for vampire bats, only a blood meal will satisfy.
Katja Rex, of the Leibniz Institute for Zoo and Wildlife Research in Berlin, Germany, and colleagues spent several months capturing bats and identifying species in three tropical rain forest locations: La Selva Biological Station, a lowland rain forest in Costa Rica; Podocarpus National Park, a highland rain forest in southern Ecuador; and Tiputini.
Tropical Boon
Though Tiputini had the highest number of bat species, the other stations also displayed rich diversity.
The authors describe 72 species at La Selva and more than 30 from Podocarpus in a recent issue of the Biological Journal of the Linnean Society.
By comparison, the number of bat species in temperate regions rarely climbs into double figures.
David Hill, a bat expert from the University of Sussex in the United Kingdom, was not involved with the study.
"To have one hundred species in such a small area is remarkable, as it represents 9 percent of all bat species," Hill said.
The high level of biodiversity in tropical rain forests gives bats an advantage, experts say.
"These bats will exploit fruit, nectar, insects, blood, and even small vertebrates, and this wide variety of food types may be the key to the high species richness there," said Gareth Jones, a bat expert from the University of Bristol in the United Kingdom.
Diverse Talents
Rex and her colleagues also observed the different skills displayed among the many bat species.
"Fish-eating bats skim the surface of waters with their legs and detect fish that come to the surface using their echolocation [biological sonar] calls. They catch them using their large feet," said Christian Voigt, Rex's Ph.D supervisor, also from the Leibniz Institute.
Frog-eating bats listen for the calls of male frogs to find their prey, and vampire bats have razor-sharp teeth to slice through the skin of their victims.
Many of the bats are also important seed dispersers and pollinators, playing an essential role in the productivity of the forest.
Unfortunately the outlook doesn't look so sunny for some of the exotic bats.
Roads built for oil prospecting and easy access to the forest encourages illegal logging, for example.
"Oil exploration and other forms of human disturbance are a great worry, because they inevitably lead to habitat fragmentation and degradation," the University of Sussex's Hill said.
"This reduces the complexity of the environment and consequently reduces the diversity of species that are able to coexist," he said.
Human influences could prove fatal for bats, Voight added. "Rain forest degradation has the potential to make most tropical bat species become extinct."
