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.