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  • Bats dancing in the moonlit forest at night.

  • This is the Daito flying fox which inhabits Minami-daito Island, a remote island 400 kilometers east of Okinawa’s main island.

  • Differing from small bats that use ultrasound to catch insects, the majority of fruit and nectar eating megabats use no ultrasound whatsover.

  • Instead, megabats have a superb sense of sight and smell.

  • The megabat’s eyes are forward facing like those of cats and bears, allowing them to view objects three dimensionally.

  • Additionally, the megabat’s optic nerve structure connects the left eye to the right brain and the right eye to the left brain for information processing, enabling swift depth perception.

  • This kind of complex optic nerve structure is only seen in primates, flying lemurs, and megabats.

  • It is said that megabats can recognize the smell given off by a single gram of fruit several hundred meters away.

  • Their highly protruding nose is shaped so as to take maximum advantage of this ability.

  • The megabat’s superb information processing ability and acute sense of sight and smell truly make it a flying sensor platform.

  • Megabats usually take shade and rest behind fan palm leaves during the daytime.

  • Even though the structure of their eyes is not especially suited to nocturnal activity,

  • it is thought that they are mainly active at nighttime to protect themselves from predators such as birds of prey,

  • and to prevent rises in body temperature.

  • Kita-daito Island is located 10 kilometers to the north of Minami-daito Island.

  • The Daito flying fox also inhabits Kita-daito Island, and there have been confirmed sightings of individuals flying between the two islands.

  • So, just how far can a megabat fly?

  • The megabat family is distributed across Africa and Polynesia.

  • The Bonin flying fox, which resembles the Guam flying fox, and the Ryukyu flying fox inhabit the vicinity of Japan.

  • Furthermore, the Ryukyu flying fox is classified into 5 subspecies; Erabu, Daito, Orii’s, Yaeyama, and Taiwanese.

  • The appearance of these subspecies differs greatly, indicating an immense period of time has passed since they branched off to inhabit disparate habitats.

  • From the degree of species specialization and the geological distance between islands,

  • it is estimated that the megabat’s ability for continuous flight does not exceed 100 kilometers.

  • So, when is it that the Daito flying fox made its journey to live here on this far away island?

  • For around 50 million years the Daito Islands have been completely isolated from all other landmasses.

  • The Daito flying fox migrated to this island and evolved independently of all other species.

  • This can indeed be looked upon as proof of the phenomenal power possessed by living things,

  • analyzing and adapting to their natural environment over countless generations.

  • Humans do not have such refined sensors with which to measure the natural world.

  • However, humankind posses the power of analysis, one that goes beyond our natural limitations.

  • The protection of this diverse and beautiful earth through the analysis of nature is a mission that has been entrusted to humankind.

Bats dancing in the moonlit forest at night.

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狐狸精 (flyng fox)

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    arbee 發佈於 2021 年 01 月 14 日
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