Indonesian langurs living in Singapore. Photo credit: Wikipedia/Andie Ang (CC BY-SA 4.0)
According to the Environmental Information Center (compiled by Jiang Wei and reviewed by Lin Dali): Recent studies have found that conservation efforts in recent decades have successfully saved some endangered bird and mammal species from extinction.uux.cn However, the number of individuals of many under-data species and subspecies continues to decline, and if a species is never discovered, it is impossible to conserve.
Experts used fecal analysis to successfully identify three new species of langurs
"We don't know anything about many species. To protect species, they must understand their habitats, feeding preferences, genetic diversity, and population health." Professor Rudolf, National University of Singapore. Rudolf Meier said.
Although DNA barcodes are increasingly becoming an important tool for identifying species, the ideal way to collect DNA is a different way for families.
One such possibility is animal feces. "In the past, we had to spend two to three years doing fieldwork to gather the most basic information about a species," Meier said, "and now we can quickly collect this information through fecal analysis." Not only can you get the DNA of the owner of the stool, but you can also understand their eating habits, intestinal bacteria and the amount of parasites."
The Guardian reported that Meier and colleagues in Singapore, Indonesia and the United Kingdom used fecal analysis to identify three new species of langurs.
The Presbytis femoralis and the East Sumatran langur (Presbytis percura) were previously thought to be subspecies of the Indonesian langur (Presbytis femoralis). But it has now been confirmed that the two Southeast Asian primates are separate species in their own right, so their risk of exposure to threats is "critically endangered" according to the IUCN Red Book assessment criteria. The third species of Roche langur identified by the research team (Presbytis robinsoni) is "near-threatened".
All three species of langurs are black, with only slightly different white markings on the face, limbs, and abdomen, and have long been considered a widely distributed species. They rarely land in the forest and are shy by nature, difficult to monitor and photograph.
Fecal analysis can complete species data collection without disturbing animals
Meier's study, Fecal DNA and Species Rescue, speaks to the difficulty of collecting information on rare species because "invasive sampling is almost an impossible task."
"There are only three other DNA sources. The first is museum specimens, but the number of specimens in museums is often small, many of which were collected in the 19th or early 20th centuries, thus reflecting historical genetic diversity before the large loss of habitat. The second is a tissue sample obtained from a specimen of an "accidental death" (e.g., road kill). The third source is non-invasive samples such as hair and feces. 」
Stool samples can be collected during routine field surveys, but this is not an easy task. Outdoor conditions are sometimes harsh and require long periods of monitoring. To ensure that the animals did not feel threatened, the researchers had to wait for individuals to leave after defecation before they could approach the feces.
One of the paper's co-authors, Andy M. Thompson, a research scientist at the Singapore Conservation Foundation for Wildlife Sanctuaries, said that the paper was not a good idea. Andie Ang said: "Langur dung in the soil is difficult to identify because the color is mostly brown. Sometimes the langur droppings fall and hit branches or leaves, scattered all over the forest floor, and we have to look for very small pieces."
"Sometimes the smell of feces is obvious enough, and sometimes it can follow the traces of flies or dung beetles."
The benefit of collecting stool samples is that they are non-invasive and do not require the capture of animals. Unlike blood collection or the use of ear clips, it does not disturb or oppress animals.
In the past, due to lack of information, several endangered langurs were not protected
The study used commercially available kits to extract DNA from langur fecal samples and send them to an external institution for sequencing. The sequencing results included a small amount of the langur's own DNA, the DNA of the food it ate, the parasite DNA, and the vast majority of it was the DNA of bacteria.
Another co-author, Amrita Srivathsan, a researcher at the National University of Singapore, said: "We used bioinformatics techniques to isolate langur DNA sequences and reconstruct the complete mitochondrial genome from it."
"Finding the three langurs has mixed feelings. Their ethnic groups are small and fragmented, which is worrying. But at least for now they can be taken care of and cared for... The information provided by the fecal analysis is important for understanding the ecology of the species and helps to develop tailor-made conservation strategies."
In Singapore, only 60 Indonesian langurs inhabit a regulated forest, while in the Straits of Johor on the southern peninsula of Malaysia, the number of individuals is also decreasing (250 to 300) due to the rapid increase in palm oil fields.
Much of the habitat of the East Sumatra langur found in The Indonesian province of Riau has been destroyed by logging and private plantations. Small groups of East Sumatran langurs are scattered throughout traditional rubber plantations, as these still have some natural vegetation. Co-author Rizaldi, a primatologist at the University of Andalas in West Sumatra, said: "Due to the lack of information on the species, it is not considered a conserved primate in Indonesia. Our paper is a critical first step in making it protected."
References: The Guardian (5 November 2020), Scatological Science: How poo analysis could help save endangered species
Reprinted from the "Environmental Information Center" website, this article is provided with domestic and foreign environmental education and environmental protection information by many experts, scholars and non-governmental groups, covering global change, greenhouse gas control, environmental protection, environmental pollution prevention, ecological conservation, energy conservation and energy efficiency, green buildings and other aspects. I hope to be able to speak for the mountains, forests, wetlands, oceans, and lands that do not have a vote.
