The Indonesian island of Flores formed its very own biotope tens of thousands of years ago: with the short Flores people Homo floresiensis, large Komodo dragons, dwarf elephants - and giant storks. The species Leptoptilos robustus, which belongs to the marabus, even towered over the human inhabitants of the island with a height of more than 1.8 meters. And despite their size, the animals were also able to fly, as new bone finds by Hanneke Meijer from the Naturalis Biodiversity Center in Leiden and her team suggest in "Royal Society Open Science".
For a long time it was thought that the way other large island birds could have lost their ability to fly. However, new excavations in the Liang-Bua cave on Flores also provided bones of the wings. These were sufficiently large and strong to allow the Marabus the flight, as the working group concluded. In contrast, there were no signs of regulations on which other birds, such as ostriches or certain races, were present. Probably nested leptoplos robustus on cliffs or trees from where they could start and then slide more easily.
Other bone finds in the cave also provided evidence of the way of life of the giants and other animals of Flores. An essential part of the ecosystem in the eyes of Meijer and Co were the dwarf elephants of the genus Stegodon, which only had a shoulder height of less than 1.3 meters. The herbivores not only ensured the spread of certain seeds and influenced the vegetation, but also formed an important food source, dead or alive. Flores-people like the Komodo dragons still present here at that time hunted them, the marabus then ate like vultures on carrion.
Dead elephants, the storks probably also lured into the cave, where some finally died: the mammals could possibly look for water or cooling inside or were broken down by humans there. The remnants then went to Aasfresser, whose bones were well preserved by the cave climate.
When the elephants died out, this had far-reaching consequences for the island nature and the species dependent on stegodon. Without the abundant food source, scavengers like the marabus and predators like the monitor lizards disappeared (which survive to this day on Komodo and a few small spots on Flores). Why the elephants perished tens of thousands of years ago is unclear. At that time, the Earth was warming up after an ice age: the island area was shrinking due to rising sea levels, at the same time the climate changes caused a change in vegetation, which the elephants might not have been able to adapt to.
However, both types are exemplary for evolution on islands: it turns giant and other dwarfs from some species. This pattern can be found on many urins worldwide and in numerous different organisms.
