More than 360 different songbird species are unique to the Eastern Himalayas, most of which cannot be found anywhere else on Earth. A new study details how exactly this came to be, and why the region's impressive avian diversity makes it an exceptionally important habitat to scientists.
The study, published in Nature, details how the hugely diverse bird community came to be millions of years ago, after the formation of the Himalayan mountains created a number of largely isolated ecological "niches."
"A wide variety of different songbird species were able to colonize these niches. The majority of these species did not evolve there but emigrated from the eastern and south-eastern regions of the Himalayas," researcher Jochen Martens explained in a recent Johannes Gutenberg University Mainz (JGU) press release.
This is rather unusual for a diverse region, as it is common for one or several species to evolve to adequately take up residencies in differing local ecological setting. In this way, the region is filled with varied birds who all descended from the same few ancestors.
This, however, does not appear to be the case for the Himalayan birds.
Instead, according to the study, the Himalayas took on a huge number of emigrated birds from the surrounding regions to fill whatever ecological niches were available.
These birds then adapted to greater differentiate themselves from the region's other populations - if not in looks, at least in communication.
Martens, who has been studying these birds for 45 years, has recorded more than 10,000 individual sounds from numerous species for his research, which he compiled in Europe and many parts of Asia. The Himilayan birds, he found, frequently developed their own dialects and changes in acoustic properties.
Since the initial "niche filling" of the Himalayas, the region has been so heavily saturated that no new colonization has occurred, encouraging the isolation of these diverse birds from the rest of the world, the authors of the study concluded.
According to the researchers, these facts are exactly what makes the region exceptionally important for the study of speciation and diversity. As the world's species diversity is reportedly declining, researchers are taking pains to better understand what encourages variety in the first place. The Eastern Himalayas, the team writes, offers a unique opportunity to study these effects thoroughly.
The study was published in Nature on April 30.