Date: March 27, 2019
Source: Louisiana State University
In the lush, lowland rainforests on the island of Borneo lives a rather common, drab brown bird called the Cream-vented Bulbul, or Pycnonotus simplex. This bird is found from southern Thailand to Sumatra, Java and Borneo. In most of its range, it has white eyes. On Borneo, however, most individuals have red eyes, although there are also a few with white eyes. For 100 years, naturalists have thought the eye-color difference on Borneo was a trivial matter of individual variation. Through persistent detective work and advances in genetic sequencing technology, Louisiana State University Museum of Natural Science researchers have discovered that the white-eyed individuals of Borneo in fact represent a completely new species. Their discovery of the Cream-eyed Bulbul, or Pycnonotus pseudosimplex, was published recently in the scientific journal, the Bulletin of the British Ornithologists' Club.
"One of the reasons we knew we had a new species as opposed to just a variant of another species was because the two populations -- the red-eyed and white-eyed populations -- actually occur together on Borneo. You can go to a site and see both of these birds. One of the theories of speciation is if two birds co-occur in the same area, and they are not interbreeding, then that's a definitive sign that they are different species," said Subir Shakya, lead author and LSU Department of Biological Sciences Ph.D. student.