There are many suspicion around the number of 1335 langur individuals in Son TraAfter 11 researching years of the Red-shanked Douc Langur in Son Tra (Da Nang) in terms of individuals, monitoring, distribution, rescue, flora and foliage ecology, the American Douce Langur Foundation has counted for the number of individuals that is very lower than the number 1335 announced by the GreenViet.
Need more time
The number as 1335 individuals of the Red-shanked Douc Langur in Son Tra was announced yesterday (22nd May) not only makes a surprise for many people but also give many suspicion in the public.
Discussion with Dan Viet’s journalist around this issues, primates expert Vu Ngoc Thanh - faculty of Biology, Hanoi University of Science (Hanoi VNU) who is holding director position of the Douc Langur Foundation (US) in Vietnam mentioned that it is necessary to spend a lot of time to study, counting and investigation that able to give a final conclusion of the relative number of the Red-shanked Douc Langur individuals in Son Tra.
With the number as 1335 individuals of the Red-shanked Douc Langur in Son Tra late announced by the GreenViet, Mr Vu Ngoc Thanh claimed that it is so impression.
“However, if the number is correct, it is necessary to plant more forage trees to support enough food for the Red-shanked Douc Langur or conduct the other activities to conserve the population with large number of individuals in that case” Mr Thanh said.
According to the claims of Mr Thanh, the study on the Red-shanked Douc Langur spends a lot of time. The GreenViet had just conduct their study but also announced their accounted number, their accuracy of this number is necessary to review, necessary to check the organization who conducted accounting and to check the person who conducted this work.
Mr Thanh said that, there are two ways to account the langur individuals, firstly, it is enumeration the number of individuals exist on a sample unit then expanding the enumeration to the large area and secondary, it is directly enumeration then directly calculating the total number.
“Both of those ways also need a long time to conduct because if people want approach to the langur, they must conduct enumeration in the suitable season and finding out their food sources. And in addition, the staff who conduct enumeration must have experiences in primates study. In this case, in Da Nang City, not much people would be adapted” Mr Thanh confirmed.
Study in a longtime but giving a lower number
The director of DLF (US) additional analyzed, both of those ways must base on the habitat boundaries of each flock when those boundaries in Son Tra have been not studied of any person or organization. And besides that, in Vietnam, there is limited on researchers because limit of time and research advances while the large budget for a research is also barrier.
“If the habitat boundaries of the langur are unidentified, it would be leaded to a mistake in enumeration as re-accounting when the langur flock move to another place (food looking for, resident or avoid disturbance caused by the human activities). Moreover, this is animal species which often have large members in foraging activities” Mr Thanh emphasized.
Mr Thanh also more mentioned, the organization that he is a representative has been conducting study about the langur in Son Tra for 11 years (since 2006 up to date) in terms of individuals, monitoring, distribution, rescue, flora and foliage ecology. This study was permitted by the Da Nang FPD.
“We have a plan for second quarter in 2017 to cooperate with the Da Nang FPD to organize a workshop to announce our researches. Those researches had been presented in some international workshops but at the moment, it is not official report to the local authorities. However, the number of langur individuals that we accounted for late 11 years in Son Tra is much lower than the announced number by the GreenViet” - the expert confirmed.