The Rare Miller’s Grizzled Langur Discovered in New Geographic Area
An international team of scientists has found one of the rarest and
least known primates in Borneo, Miller’s Grizzled Langur, a species
which was believed to be extinct or on the verge of extinction. The
team’s findings, published in the American
Journal of Primatology, confirms the continued existence of this
endangered monkey and reveals that it lives in an area where it was
previously not known to exist.
Miller’s Grizzled Langur (Presbytis hosei canicrus) is part of the small
primate genus Presbytis, found across Borneo, Sumatra, Java and the
Thai-Malay Peninsula. In Borneo P.h. canicrus is only found in a small
corner of the county's north east and its habitat has suffered from
fires, human encroachment and conversion of land for agriculture and
mining.
The team’s expedition took to them to Wehea Forest in East Kalimantan,
Borneo, a large 38,000 ha area of mostly undisturbed rainforest. Wehea
contains at least nine known species of non-human primate, including the
Bornean orangutan and gibbon.
“Discovery of P.h canicrus was a surprise since Wehea Forest lies
outside of this monkey’s known range. Future research will focus on
estimating the population density for P.h. canicrus in Wehea and the
surrounding forest," said Brent Loken, from Simon Fraser University
Canada. "Concern that the species may have gone extinct was first raised
in 2004, and a search for the monkey during another expedition in 2008
supported the assertion that the situation was dire."
By conducting observations at mineral licks where animals congregate and
setting up camera traps in several locations, the expedition confirmed
that P. h canicrus continues to survive in areas west of its previously
recorded geographic range. The resulting photos provide the first solid
evidence demonstrating that its geographic range extends further than
previously thought.
“It was a challenge to confirm our finding as there are so few pictures
of this monkey available for study,” said Loken. “The only description
of Miller’s Grizzled Langur came from museum specimens. Our photographs
from Wehea are some of the only pictures that we have of this monkey.”
"East Kalimantan can be a challenging place to conduct research, given
the remoteness of many remaining forested areas, so it isn't surprising
that so little is known about this primate,” said Dr. Stephanie Spehar,
Assistant Professor of Anthropology at University of Wisconsin Oshkosh.
"We are very grateful to our local partners. This discovery represents
the hard work, dedication, and collaboration of Western and Indonesian
scientists, students, NGOs, as well as local communities and government."
“While our finding confirms the monkey still exists in East Kalimantan,
there is a good chance that it remains one of the world’s most
endangered primates,” concluded Loken. “I believe it is a race against
time to protect many species in Borneo. It is difficult to adopt
conservation strategies to protect species when we don’t even know the
extent of where they live. We need more scientists in the field working
on understudied species such as Miller’s Grizzled Langur, clouded
leopards and sun bears.”
