The magpie-robin found in Sarawak spotted a white belly, while in Sabah it is black. The bird species in Sabah said to be closely related to their cousins on the montane of Java island instead of Sarawak.
How could birds of same species found on same island could be distinctively different?
That is a uniquely Borneo phenomenon according to Louisiana State University don, in a public lecture attended by lecturers, university students, pupils, teachers and government officers held at Universiti Putra Malaysia (UPM) Bintulu on Thursday.
Professor Frederick H. Sheldon said the phenomenon can be explained by looking back to some 21,000 years ago. The ice age era. During that period, we were told much of the South China Sea was actually a Savannah – not sea, teeming with life – including birds.
The part of Borneo, now known as Sabah, then was much drier, with desert-like weather not the tropics. In contrast, Sarawak spanning towards Kalimantan, Indonesia was colder, lowland areas and green. This flora and fauna divide basically explained why birds found in present day Sabah and Sarawak are different.
“Bird of same species for example the Sharma and Pitta have distinctive Sabah or Sarawak features,” he said, adding “Sarawak Sharma spotted a white-rumped, while in Sabah they are white-crowned; Sarawak – Garnet Pitta, while Sabah Black and crimson Pitta.
“Many would say the birds in Sabah should be similar to those found in Sarawak as they are living on the same island,” Prof Sheldon said. Sarawak birds he said are closely related to peninsular birds, while Sabah birds resembled those found in the montane of Java island.
He also pointed out that some bird species found throughout Borneo, but not in Sabah – for example the Crestless Fireback (Lophura eryhrophthalma). Similarly, some lowland birds like the Chestnut-necklaced Partridge (Arborophila charltonii) only occur in Sabah not the rest of Borneo.
Prof Sheldon, 60, is no stranger to Borneo. He first set foot on the island about 35-year ago as a young, excited Yale university postgraduate student studying birds biogeography in Sabah. He also get a teaching stint at then Universiti Kebangsaan Malaysia (UKM) Sabah campus. Ever since, have been regularly return to this part of the world.
“I would return to Malaysia like every five year. Each visit I saw different phases of development,” he said, adding only small part of Kinabatangan river were cultivated for commercial large scale plantation, then.
“Three decades ago when you told people you wanna go up the Kinabatangan river, they say you are crazy,” he recalled, saying Malaysians then were generally ignorant of the important environmental conservation, unlike they are today.
“Today people already saw the benefits of biodiversity conservation and actually proud to show you the forest in their surrounding,” Prof Sheldon said.
As a biologist, Sheldon confessed he is very protective of the environment and is more at ease working in the jungle, surrounded by animals, birds and insects than in air-conditioned office. Throughout his nearly two hours lecture, Prof Sheldon stressed the message of conservation of Borneo vast biodiversity.
“Do you know that Borneo is the center of biogeography studies in the world?” he said, and that Malay archipelago is the birthplace of biogeography studies.
Prof Sheldon acknowledged Sarawak’s biodiversity was still largely protected and thriving despite the immense pressure to meet the country’s development needs, which could lead to biodiversity losses in other part of the world.
He said Malaysian authorities in many aspects have succeeded in balancing those needs without compromising the environment.
“The creation of buffer zones in a plantation area is crucial at sustaining biodiversity,” he said, pointing to observations they had done at acacia mangium plantation, in Tatau, near Bintulu.
“The acacia plantation actually useful to the birds in the areas as it provides abundance of food supply.
Currently, an Adjunct Professor in Biological Sciences at Louisiana State University, Sheldon had published more than 34 journals/books in his field of interest: the evolution and systematics of birds, and the natural history of the birds of the Malay archipelago.
This article was also published at The Star (printed version) Saturday, March 19, 2011