Sarangani
tarsiers different subspecies from Bohol's
Carolyn O.
Arguillas / MindaNews
DAVAO CITY
(MindaNews/10 April 2002) -- The tarsiers of Sarangani
belong to a subspecies of Philippine tarsiers different
from Bohol's.
Though the
Philippine tarsier (Tarsius syrichta) is an understudied
creature compared with other tarsier species in Southeast
Asia, three subspecies are presently recognized: T.s
syrichta from Leyte and Samar, T. s. fraterculus from
Bohol and T.s. carbonarius from Mindanao.
"This
perspective may change as scientists are beginning to
study the variation found in tarsiers throughout the
Philippines," said Sharon Gursky, an expert on
tarsiers and an assistant professor of Anthropology at the
Texas A&M University.
MindaNews e-mailed
the Philippine Tarsier Foundation in Bohol for answers and
attached photographs of the Sarangani tarsiers, but the
Foundation has yet to reply.
In her answers to
MindaNews' queries by e-mail, Gursky, who was also sent
photographs of the Sarangani tarsiers, said that while she
is an expert on tarsiers, her work is focused on
Sulawesian tarsier species Tarsius .
Extensive studies
have been made on the Sulawesian tarsiers' morphology,
range, ecology, locomotion, social behavior, vocal
communication, olfactory communication, visual
communication, tactile communication, and reproduction,
among others.
Gursky said it is
"difficult to say with certainty" if the
tarsiers in Bohol and the tarsiers in Mindanao are the
same or different.
"Whether the
differences represent specific level differences
(different species) or subspecific differences
(subspecies) is based on numerous biological factors such
as whether the tarsiers from Bohol and Mindanao can
reproduce together, whether they respond to each other's
vocalizations, chromosomal numbers, etc." she said.
On what to do with
the tarsiers captured in Sarangani, Gursky said "they
should be returned to as close to where they were captured
as possible."
Gursky said
Mindanao tarsiers should not be released in Bohol because
"we do know that they are different subspecies and
therefore should not be mixed."
Gursky said another
reason why the tarsiers in Sarangani should be released is
because "tarsiers are very difficult to maintain in
captivity."
Gursky said that 20
years ago, "Pat Wright brought 20 tarsiers back to
the USA from the Philippines and Malaysia to be housed at
the National Zoo and the Duke University Primate Center.
They have all since died. We have had no success
maintaining captive tarsiers."
Marian Dagosto of
the Department of Cell and Molecular Biology at the
Northwestern University in Chicago, who studied the
tarsiers on Leyte in 1997 and 1998, said tarsiers
"are known from many places in the Southern
Philippines, including Bohol, Leyte, Samar, and Mindanao
(from many localities), and from some smaller surrounding
islands like Basilan and Dinagat."
Dagosto told
MindaNews in another e-mailed message, that there is
"a large collection from Davao del Sur, made in the
1950's, in the Philippine National Museum and other museum
specimens from Maguindanao, Surigao, and Zamboanga. But I
don't know of any previous specimens from Sarangani
province."
Dagosto said the
pictures of the Sarangani tarsiers which was sent to him,
"appear to be similar to other Mindanao tarsiers, but
external characters are not always the most useful for
these animals."
"It is still
an open question, and in fact, the focus of my current
research, how many species or subspecies of tarsiers live
in the Philippines. The currently accepted taxonomy is
that there is only one species, with three subspecies: T.
syrichta syrichta, from Leyte and Samar; T. s. fraterculus
(Miller, 1911) from Bohol; and T. s. carbonarius (Heude,
1898) from Mindanao."
Dagosto said a
specimen from Dinagat (Surigao del Norte), "is larger
than other Philippine tarsiers and may also be
taxonomically distinct (Heaney and Rabor, 1982). On the
other hand, the morphological grounds originally given for
recognition of these subspecies are rather unconvincing
and both Hill (1953a, 1955) and Niemitz (1984a) doubt the
existence of identifiable subspecies. There is as yet no
genetic data with which to evaluate the status of the
proposed subspecies."
In a separate
e-mail, Myron Shekelle, Research Associate at the Center
for Biodiversity Studies and Conservation, Faculty of
Mathematics and Science at the University of Indonesia,
told MindaNews that "the type locality of Tarsius
syrichta is the island of Samar."
Shekelle said
tarsiers "are also known from several other islands
in the southern parts of the Philippines including Leyte,
Bohol, Mindanao, Siargao, Dinagat, Basilan, and probably
dozens or even hundreds of other smaller islands."
"All of these
islands are believed to have formed a single landmass
during the ice ages and scientists sometimes refer to this
landmass as 'greater Mindanao'," Shekelle said.
Shekelle added that
the taxonomy of Philippine tarsiers is not well
understood, "partly because the past two decades have
taught us that acoustic and genetic data are often crucial
for the taxonomy of nocturnal primates, such as tarsiers,
and there are almost no such data at all for Philippine
tarsiers."
The Bohol tarsiers,
Shekelle said, "are a questionably justifiable
subspecies known as T. syrichta fraterculus."
"Few
taxonomists accept the Bohol tarsier as a distinct
subspecies, but, who knows? There really aren't any data
at all worth mentioning. The same is true for the Mindanao
tarsier. Few taxonomists accept that it is a distinct
subspecies, but if it were, it's name would be T. syrichta
carbonarius."
Shekelle said the
Mindanao tarsier "gets its name because of the false
folk belief that tarsiers eat charcoal from leftover
campfires."
"Make sure
that the tarsiers are being fed grasshoppers, crickets,
house geckos, and other live caught animal prey,"
Shekelle said.
"Everywhere I
go, the folk wisdom of the tarsier diet is very far from
accurate," Shekelle said. "Don't even bother
trying to feed tarsiers fruit, leaves, rice, or anything
other than food such as I mentioned.
Shekelle does not
condone amateurs catching tarsiers and keeping them as
pets, "but I see this from time-to-time in my
work."
"My
conservation philosophy is that the whole battle will be
won or lost through 'hearts and minds,' not through
enforcement -- this is particularly true in the
countryside as opposed to the city-- therefore, when i
meet someone with a captive tarsier, I engage him in a
discussion of tarsier diet, behavior, and the tarsier's
role in the local ecosystem, and then hope that the person
will have sense enough to let the tarsier go. I then
include these encounters in my regular reports to the
Indonesian authorities," Shekelle said. (Carolyn O.
Arguillas/MindaNews)
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