The Wangi-wangi white eye (L) and the Wakatobi white-eye (R). Professor Nicola Marples Professor Nicola Marples

ZOOLOGISTS AT TRINITY College Dublin have discovered two new species of birds following 20 years of research on the Indonesian island of Sulawesi. 

Found on the Wakatobi Archipelago of the island, the indigenous Wakatobi white-eye and the Wangi-wangi white-eye bird species were discovered by Dr Nicola Marples’ team which has studied the biodiversity and bird species there since 1999.

The recent discoveries shed light on how these species developed, Marples told TheJournal.ie. But they also bring new environmental and conservation challenges. 

Sulawesi lies in the middle of Indonesia, which sits at a geographic boundary between Asian and Australian species.

The island has an unusually high number of endemic species – unique species found nowhere else -  due to the deep ocean trenches that isolated it from other land masses, even during past ice ages when ocean levels dropped.

Defining species is far from straightforward, however, and was for many decades open to interpretation.

Using modern research methods in determining species separation, Marples and her team incorporated genetic, body size and song measures as a means of comparing birds.

Differences in bird song are particularly important in this task as birds use their songs to find their mates, Marples has said.

So, if separated populations of birds sing different songs they won’t interbreed, which enables them to evolve in different directions.

‘Ecological challenges’

Eventually, after a number of generations, birds in the different populations may be sufficiently different to be classified therefore as unique species. Thus, the Wakatobi white-eye and the Wangi-wangi white-eye now being classed as separate species. 

For decades, the Wakatobi was thought to be a sub-species but, following genetic research, Marples’ team have now believe the bird is its own unique species.

The Wangi-wangi was only discovered in 2003 by Marples’ team. 

Adaptable birds, both white-eye species feed on a wide variety of fruits, flowers and insects. White-eyes are also island colonisers, which is why so many different white-eye species have evolved so rapidly.

The Wangi-wangi white-eye is a much older species, Marples has said, and it is only found on one tiny island. “It’s not even on the little satellite islands.”

Of course, with any discovery comes ecological challenges. 

Lead author of the journal article on the Trinity team’s discovery, Dr Darren O’Connell, has said that both species of bird are at risk. 

“By highlighting the unique species special to the Wakatobi Islands we can help safeguard the remaining habitats on the islands, which are under huge pressure,” O’Connell has said.

“We ultimately hope to have the islands recognised as an Endemic Bird Area so that they receive more conservation support.”