NEO CHAI CHIN Today Online 21 Jan 17;
SINGAPORE — You probably could not tell from the abundance of Javan mynas in Singapore, but the yellow-beaked grey bird is a victim of the illegal wildlife trade in its native range in Java, where its population has plummeted.
Its wild population in Java and Bali in Indonesia is estimated to be between 2,500 and 9,999. In contrast, more than 100,000 of them are found in Singapore, where they were introduced via the caged bird trade and have been established since 1925.
Dr Luke Gibson of the University of Hong Kong and Mr Yong Ding Li, a Singaporean PhD student at Australian National University, have proposed in a new research paper two ways in which Singapore and other cities can help in the conservation of globally threatened species.
The harvest of mynas and other species introduced here, such as the Red-breasted parakeet and Goffin’s cockatoo in Singapore, could offset demand from the pet trade in their native ranges, they said.
The Red-breasted parakeet is quite common on Pulau Ubin and the western catchment area, and its population here is likely to be in the thousands, Mr Yong said. The Goffin’s cockatoo, also called the Tanimbar cockatoo, is found on the remote Tanimbar Islands of Indonesia, and its Singapore population is believed to have originated from captive individuals that escaped. It has since built sustaining populations in places such as Changi Village, and Mr Yong estimated that there are a few hundred of them in Singapore.
A second approach is for these populations to be reintroduced to their native ranges to buffer declining populations.
“As many species disappear from their native ranges while thriving in other parts of the world where they have been introduced, we urge conservationists to explore innovative approaches to protect species,” the authors wrote in the paper, published this month in the journal Frontiers in Ecology and the Environment.
The suggestions may invite questions on whether introduced populations would indeed ease pressure on native populations and how their impact can be effectively monitored. Would the harvesting of introduced populations also reinforce the notion that it is acceptable to keep wildlife as pets?
Mr Yong said that to some extent, the trade in pet birds is driven by humans’ fondness for rarer species. “I think harvesting these populations could increase the supply of individuals of these animals and thus affect supply chains. When this happens, it may not be so attractive to keep such species as pets,” he told TODAY. “I believe such a solution is better than maintaining the status quo.”
With wildlife trade, some species pushed to the brink of extinction have at the same time been deliberately or accidentally released in new places and have established feral populations, threatening the native species and habitats of those places.
In Singapore, the Javan myna has out-competed the Common myna. Elsewhere, invasive populations of Burmese pythons have caused populations of native mammal species in the Florida Everglades to crash, while in their native South-east Asia, the pythons have been relentlessly harvested for their skin, for medicine and for the pet trade.
Other experts agree with the authors’ proposals and precautions to be taken. Dr Darren Yeo of the National University of Singapore’s Freshwater and Invasion Biology Laboratory noted that the authors have flagged the need to first consider if harvesting of introduced populations would elevate demand and poaching of native populations. Regulations under the Convention on International Trade in Endangered Species (Cites) may have to be met if the species is threatened, Dr Yeo added. “If Cites is not applicable to introduced populations, then there must still be measures to ensure or certify that the traded individuals are indeed from the introduced populations,” he said.
On the suggestion to re-introduce animals drawn from introduced populations, Dr Chris Shepherd, regional director of wildlife trade monitoring network Traffic in South-east Asia, agreed that such efforts should not be pursued until populations in their native ranges are better studied and have receive improved protection. Otherwise, the re-introduced populations would simply be hunted out again, he said.
Disease transmission is a threat and the genetics of many species in the region have not been adequately worked out, so there is a risk of trans-locating species or sub-species into areas where they are not native, Dr Shepherd added. “If these considerations are met, this is a feasible conservation strategy and ... is one of the actions considered for the Javan myna under the conservation strategy for South-east Asian songbirds in trade (arising from a summit in September 2015),” he said.
NEO CHAI CHIN Today Online 21 Jan 17;