ANN/THE STRAITS TIMES – Singapore’s urbanization and deforestation of its land, forming the modern country it is today, was thought to have resulted in the loss of at least two-thirds of its biodiversity.
However, a recent report revealed that this is not the case, with the loss of plant and animal species in the city-state being only 37 percent. This is almost half the estimated extinction rate, according to his much-cited 2003 paper.
The latest study, published in the scientific journal Proceedings of the National Academy of Sciences in December 2023, involved 27 experts and young researchers and used a new mathematical model.
Most notably, a 10-year study led by theoretical ecologist Ryan Chisholm at the National University of Singapore (NUS) developed a statistical method to explain the dark extinction (an unknown number of plants and animals that went extinct before they were discovered). This is what we developed.
Globally, these silent extinctions pose a problem for scientists trying to chart the true scale of human extinctions.
Associate Professor Chisholm, who came up with the research idea in 2012, said: “This discovery is important for Singapore.”
“[This study]provides more accurate estimates of extinction than previous studies, where large, charismatic species are identified as being particularly at risk of extinction.”
Charismatic species are plants and animals that attract more public attention because of their aesthetic appeal or cultural significance. For Singapore, Mr Chisholm said examples of these species include pangolins and orchids.
The historical record of the flora and fauna here is poorly studied, making it difficult to know how many species once existed on the island.
Dr Tan Hek Hui, curator of fishes at the NUS Natural History Museum and co-author of a recent paper, said the earliest checklists date back to the 1960s, and almost 20 years have passed since then, so the island’s original freshwater fish He said it was likely that many of the incidents had not been recorded. Vast mangrove forests and freshwater forests had been cleared.
“Although the record of freshwater fish may not be complete, it still provides important clues to past events,” he said.
To paint the most accurate picture of extinction in Singapore, researchers have painstakingly constructed a comprehensive record database of more than 50,600 observations of more than 3,060 species in 10 major plant and animal groups.
The library has everything from Singapore’s oldest natural history material, a sea teak stem collected in 1796, to social media sightings and a photo of a black-headed snake taken by Prime Minister Lee Hsien Loong. This includes civil records such as:
For groups like birds with more extensive data sets, new statistical models were created to estimate each species’ probability of extinction and estimated extinction date by processing all available records. Researchers found that as a result of deforestation and urbanization over the past 200 years, native butterflies faced the highest estimated extinction rates, with nearly half of their species extinct, followed by honey bees, with 42% extinct. discovered.
Three out of five mammals weighing over 10 kg, including leopards, have gone extinct.
Nearly 90% of bird species that depend on old forests were also expected to become extinct. Orchids were the most affected plant species, with 68 percent of known species lost.
Co-author of the study, NUS assistant professor John Asher, who specializes in bees and hornets, said the main bees known to have been lost were those that were dependent on forests.
“Unfortunately, some of the most valuable species for meliponiculture (the practice of breeding meliponiculture for honey and honeycomb products), which are widely kept in nearby Malaysia, have been lost from Singapore, leaving us with honey and pollination. “we were robbed,” he added.
“Many of these bees needed extensive dipterocarp forests for nesting and foraging,” he added. The Dipterocarpaceae family consists of tropical hardwood trees such as the Chengal tree.
Asher believes these new estimates are more realistic than a 2003 paper published in the journal Nature that described the Dark Extinction.
“The numbers were so large that it was inconceivable that there could be so many extra species in Singapore,” he says. – Ann Ching