Islands make up almost one sixth of the planet's land surface, and many islands have unique flora and fauna because plants and animals have evolved on them in isolation. In fact, nearly a third of the planet's biodiversity hotspots are on islands large and small.
Many islands continue to surprise even seasoned biologists by producing new species for science. One such example is Sulawesi, a large equatorial island in Indonesia that features rugged mountain ranges and pristine coastlines. Recently, during a six-week expedition, a team of scientists discovered a total of 10 new species of birds in the area: five new species of songbirds. and the same avian subspecies.
And they did it only on three small remote islands near Sulawesi. Biologists decided to investigate the small islands east of Sulawesi due to the area's relative isolation and geological history, following in the footsteps of early researchers and explorers.
Sulawesi is where British naturalist Alfred Russel Wallace embarked on a famous excursion in the 19th century, which led him to devise the theory of evolution through natural selection independently of Charles Darwin.
Recently described songbird species include the Taliabu grasshopper warbler, Peleng's rooster's tail, Taliabu's leaf warbler, Peleng's leaf warbler, and Taliabu's myzomela.
Added to the list of birds new to science are five avian subspecies: the Togian Jungle Flytrap, the Banggai Mountain Flytrap, the Taliabu Snow-browed Flytrap, the Taliabu Island Thrush, and the Leaf Eater. from the Sula mountain.
It is highly likely that several other species of birds and other animals are waiting to be discovered in the area. "Our findings suggest that humans' understanding of biogeographically complex regions such as Wallacea remains incomplete," the researchers write in a study published in the journal Science, referring to an area comprising an island group around Sulawesi by its scientific name.
Traversing remote forests and mountainous areas on three small-group islands near Sulawesi, Frank Rheindt, an ornithologist at the National University of Singapore, and his team ventured into little-explored terrain. His findings were beyond his wildest expectations.
On the island of Taliabu alone, scientists found what they would call the Taliabu Grasshopper Warbler, the Myzomela Taliabu, and the Taliabu Leaf Warbler. They also discovered three new subspecies: Taliabu Snow-browed Flycatcher, Taliabu Island Thrush, and Sula Mountain Leaf Litter.
Nearby, on Peleng Island, they came across the Peleng dovetail and the Peleng-leaved warbler, as well as a new subspecies, the mountain leaf Banggai.
Then, on the island of Togian, they discovered the homonymous flycatcher Togian, a newly described subspecies.
"It is a real surprise to see that in the 21st century there is still one place on Earth, a relatively limited area, where there are new subspecies and five new species of birds," says Rheindt. "This shows that there are still many areas on Earth that are poorly explored."
Now that these new birds have been discovered for science, the task is to preserve them for posterity in their natural habitat. "Urgent and durable conservation measures are needed for some of the new forms to survive more than a couple of decades beyond their description date," emphasizes Rheindt.
"It is almost a shame for humanity that we have mapped the moon and gone to the depths of the ocean, but we only know between 6 and 7 percent of the planet's species," adds the ornithologist. "The rest is not described, perhaps it will soon be extinct without our knowing it."