A recent study sheds light on how wild animals in Asia have managed to survive and avoid extinction over the past 12,000 years. These animals include tigers, elephants, wild pigs and clouded leopards.
The study titled “Megafauna Extinctions Produce Idiosyncratic Anthropocene Assemblages” by Zachary Amir, Jonathan H. Moore and colleagues on the University of Queensland, published within the Science Advance Journal on October 21, 2022, Volume 8, Issue 42, indicates that population growth of those 4 species in areas with human infrastructure.
Scientists delved into the paleontological record to match the historical distribution of 14 of Asia’s largest species, comparable to tigers [Panthera tigris]sun bears [Helarctos malayanus]leopards [Panthera pardus]holes [Cuon alpinus]and clouded leopards [Neofelis nebulosa].
They also studied nine other large species, including Asian elephants [Elephas maximus]Sumatran rhinoceros [Dicerorhinus sumatrensis]Gaurs [Bos gaurus]Bulls [Bos javanicus]tapirs [Tapirus indicus]sambar deer [Rusa unicolor]wild pigs [Sus barbatus]Sumatran cheeses [Capricornis sumatraensis]and wild [Sus scrofa].
“Fossil evaluation shows that megafauna extinction aspects modified dramatically between the Pleistocene [between 2.6 million and 11,700 years ago]Holocene [11,700 to 100 years ago]and the Anthropocene era [less than 70 years from now]” – wrote the researchers.
In the Pleistocene, geological, climatic and biological processes proceeded slowly, including: sea level fluctuations shaped the dynamics of extinction. During the late Pleistocene and early Holocene, rapid megafauna extinctions occurred, coinciding with human colonization and settlement, combined with climatic aspects affecting habitat availability.
Human influence on biodiversity patterns has increased over time because the mid-Twentieth century [1950 onwards]within the period now called the Anthropocene, each direct and indirect human actions have grow to be the principal drivers of species existence.
“Extinctions continue to occur, and at least 322 land vertebrates have become extinct since 1500,” the scientists explain.
To document the destruction of megafauna and measure their abundance, scientists conducted camera trap surveys in ten major tropical forest landscapes in Sumatra, Kalimantan, Singapore and Thailand.
Sampling in Sumatra took place in Gunung Leuser National Park, Kerinci Seblat National Park, and Bukit Barisan Selatan National Park. These three tropical forests are on the UNESCO list of rainforest reserves in Sumatra.
“All of Sumatra’s landscapes consist of primary forests and smaller forests cleared more than 20 years ago, with moderate levels of hunting.”
Sampling in Kalimantan was conducted in Lambir Hills National Park, Malaysia, an area with high hunting pressure.
In Singapore, samples were collected within the Central Catchment Nature Reserve and on small offshore islands comparable to Pulau Ubin. In Thailand, this was in Khao Banthat Wildlife Sanctuary, a fragmented forest along low mountains near densely populated areas, and in Khao Yai National Park, an intact primary forest connected to the Dong Phayayen-Khao Yai Forest Complex.
“All studied landscapes belong to the Sunda biogeographic subregion, except Khao Yai National Park, which is located in the Indo-Malay biogeographic subregion,” the researchers wrote.
The study focused on Southeast Asia because scientists say the region is ideally suited to check dynamic threats to conservation, maintaining a high diversity of megafauna while also experiencing extreme deforestation and hunting, with the very best percentage of endangered megafauna on this planet.
“The region also has a unique geological, climatic and anthropogenic history, including the largest supervolcanic eruption in the Quaternary period [Toba Caldera Complex, 75,000 years ago]dramatic sea level changes connecting and separating Java, Sumatra, Kalimantan and the Malay Peninsula.”
“We documented remarkable differences in megafauna extinction patterns and abundances across Southeast Asia, indicating that species responses to disturbances are more complex than previously estimated.”
Among all these aspects, forest degradation and human pressure have played a major role within the lack of megafauna.
“We predict that megafauna abundance is now closely linked to forest cover and negatively related to humans,” the scientists explained. Interestingly, this research shows that several animals, comparable to tigers, clouded leopards, Asian elephants and wild pigs, show a positive correlation with forest degradation or human presence. They survived despite the specter of extinction and developed with the presence of humans.
Meanwhile, eight of the 14 megafauna species experienced extinction throughout the Holocene and Anthropocene epochs.
“The disappearance of the Sumatran rhinoceros from all our surveyed landscapes is likely due to horn hunting pressure and low reproduction among the few remaining females.”
On the opposite hand, wild pigs were subject to minimal hunting pressure resulting from the “halal and haram” status of their meat and showed the very best reproductive capability amongst megafauna.
Carnivores comparable to tigers, leopards and clouded leopards were at high risk of losing prey to illegal hunting and subsequently became extinct at higher rates than sun bears, mainly insect and fruit eaters.
“The positive relationship between population size and human pressure might be explained by specific landscape protection and law enforcement,” the researchers wrote.
The reason for the disappearance of wildlife in Sumatra appears to be rapid deforestation for the production of cellulose, rubber and palm oil.
“We are concerned that megafauna extinctions in Sumatra may increase,” the scientists said. Quoting ScienceDay by day, Zachary Amir from UQ’s School of Biological Sciences and Ecological Cascades Lab explained that these findings show that under certain conditions some large animals can live near humans and avoid extinction.
However, the decline in animal populations is resulting from hunting, especially of larger species. The study also found that deforestation continues to affect species survival.
Amir mentioned that research shows that if large animal species aren’t hunted, they’ll live in relatively small habitats near humans.
Original article in Indonesian Here
