A new study reported in the open-access journal ZooKeys provides details on the taxonomy, biology, and population status of the Mortlock flying fox (Pteropus pelagicus).
A Mortlock Islands flying fox in flight on Oneop Island. Image credit: Danko Taborosi.
The Mortlock flying fox is a large, breadfruit-eating bat in the family Pteropodidae native to a few remote and tiny Pacific islands. This species has long been regarded as one of the world’s least studied bats.
For more than a century biologists knew about this bat was derived from one lonely specimen preserved in the Natural History Museum, London.
The specimen was collected in 1870 from the Mortlock Islands, a series of atolls that are part of the Federated States of Micronesia in the west-central Pacific Ocean. British biologist Dr Oldfield Thomas used this specimen to name the species Pteropus phaeocephalus in 1882.
But during a recent study of the bat, Dr Don Buden from the College of Micronesia – the first author of the ZooKeys paper – discovered that a German naturalist voyaging on a Russian expedition had observed and named the animal some 50 years earlier.
“We found a report written by F.H. Kittlitz in 1836 describing his expedition to the Pacific Islands in the late 1820s. In that report he describes the flying-foxes of the Mortlocks and names them Pteropus pelagicus. This means the species was named long before Thomas’s description in 1882,” Dr Buden said.
In the current study, Dr Buden and his co-authors straightened out a second point of confusion in the scientific literature regarding the Mortlock flying fox.
They demonstrated that flying foxes from the nearby islands of Chuuk Lagoon, long regarded as the separate species Pteropus insularis, are best regarded as a subspecies of Pteropus pelagicus. This finding shows that the Mortlock flying fox has a wider geographic distribution than previously realized.
This 1882 illustration from Proceedings of the Zoological Society of London shows the Mortlock Islands flying fox.
The team also found that the Mortlock Islands support a small population of 900 to 1,200 bats scattered across a land surface of only 4.6 square miles.
In their study of Mortlock Islands geography, the scientists learned none of the islands are more than a few meters high. Rising sea levels, generated by climate change, pose a serious threat to the flying foxes’ habitat and its food resources through flooding, erosion and contamination of freshwater supplies.
Study co-author Dr Kristofer Helgen from the Smithsonian’s National Museum of Natural History said: “this flying fox may be the best example of a mammal species likely to be negatively impacted by warming global climates. Here is a tropical mammal that has survived and evolved for hundreds of millennia on little atolls near the equator. How much longer will it survive as sea levels continue to rise?”
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Bibliographic information: Buden DW et al. 2013. Taxonomy, distribution, and natural history of flying foxes (Chiroptera, Pteropodidae) in the Mortlock Islands and Chuuk State, Caroline Islands. ZooKeys 345: 97–135; doi: 10.3897/zookeys.345.5840
