A recently discovered species of monitor lizard was reported last week in the journal Zootaxa by a team consisting of a UCSB professor and a Finnish researcher.
Samuel Sweet, a professor of Ecology, Evolution and Marine Biology at UCSB, worked with Valter Weijola, a graduate student and researcher at Abo Akademi University in Turku, Finland, to compose the first description of the lizard. According to Sweet, the Varanus orbor, a close relative of the Komodo dragon, crossed paths with Weijola accidentally last March. Sweet said Weijola was laid over on Indonesia’s Sanana Island while en route to another island.
“That boat was delayed (in Indonesia they often are), so he went for a day’s walk in the forest and came across this unexpected animal,” Sweet said. “Four foot long lizards are not that hard to notice, but until Valter Weijola had a look, no biologist with even a basic familiarity with monitor lizards had been there.”
The Varanus obor got its nicknames the “Torch monitor” and the “Sago monitor” because of its bright red-orange head and sleek, black body. Unlike its close fruit-feasting relative recently found in the Philippines, the obor — meaning “torch” in Indonesian — feeds on small animals and carrion. Sweet said surprisingly, the new reptile — like many other monitor lizards east of the Wallace line — sits “at the top of the heap” in places like Indonesia, New Guinea, and Australia.
“There are more species there, doing more different things ecologically than in Africa or South and Southeast Asia, where competition and predation by mammals tend to keep monitor lizards down,” Sweet said.
Due to its uniquely low count of mammalian predators, the Sanana Island in Indonesia’s Sula Islands provides a safe and nourishing home for the monitor. Because Sanana Island was once situated near New Guinea several thousand years ago, it is possible that the Torch monitor developed from that time period. As of yet, it is the only black-bodied, red-faced lizard roaming Sanana Island’s 138,000 acres. But as Sweet said, this is no news to the natives.
“Local people on Sanana see them every day, of course,” Sweet said. “No one minds them much since they leave their chickens alone, and are not considered edible.”
Nevertheless the locally named “soa-soa hitam” or “black lizard” encourages biologists to dig deeper. According to Sweet, almost 20 previously undescribed species of monitor lizards have been named in the past 15 years. Sweet said these discoveries change the way scientists view the evolutionary history of the family.
“[This] shifts the biogeographic emphasis from one of a few widely-distributed species that are good overwater colonizers to a picture where most islands have their own unique species and communities that have been in those places quite a long time,” Sweet said. “In general, discoveries like this point out that we really are not done yet in simply characterizing the biodiversity of tropical areas like the Indonesian islands.”