A drop in the population of endangered black-faced spoonbills has tourists and bird watchers scratching their heads, on the eve of the anniversary of the founding of Taijiang National Park.
Hong Kong’s Bird Watcher Society, which is conducting a census of bird populations around the world, announced at the end of March that the population of black-faced spoonbills, also known as Platalea minor, rose steadily over the past decade, with a spike in 2010, when the total population reached a record high of 2,346.
However, the global census for January last year found only 1,848 spoonbills, a 21 percent decrease, the steepest drop since 1993 when the census began.
According to the count, only 700 black-faced spoonbills were seen in the Greater Tainan area, a fall of nearly 1,000 from the population recorded in November 2010. The birds have also disappeared from their main habitat near the mouth of the Tsengwen River (曾文溪).
This has left bird watchers wondering what has happened to the birds.
“They are wintering somewhere else,” is the most popular theory among ornithologists, with some suggesting that the birds flew to China, Hong Kong or Vietnam for the winter.
However, some also worry this could be a repeat of the 2002 incident, when 71 died from clostridium botulinum poisoning (botulism).
Amateur bird watchers are not the only ones worrying. Environmental protection groups and academics, as well as officials from Greater Tainan City Government and the national park, are equally puzzled.
The theory that “they flew elsewhere” has since been been debunked by the census, which shows a slight decrease in the population in Hong Kong and China, and only a slight increase in Macau, Vietnam and Japan.
Tainan Bird Watchers Association chairman Lee Yu-jen (李裕仁) said the missing birds might still be in Taiwan, but could have been missed by the census if they had left their usual habitats because of territorial expansion by other bird groups, cold weather or a decrease in food supply.
“More information must be gathered so we can take the next step toward reaching a conclusion,” former Chunghwa Bird Watch chairman Kuo Tung-hui (郭東輝) said.
Taijiang National Park said it had recently asked National Taiwan Normal University professor Wang Ying (王穎) to convene a meeting with environmental -protection groups and conduct a joint investigation. At the meeting it was decided that this year’s Greater Tainan area census would use the Taijiang park management office as a communications base and expand the census to include the outlying islands of Kinmen, Matsu and Penghu.
The meeting also decided to increase the census frequency to twice a month, as well as to call on all birdwatchers and volunteers to conduct a nationwide census in November.
Officials from the Taijiang management office said this year they also plan to use wireless radio emitters to track the movements of the spoonbills, to give a more accurate picture of the numbers of wintering birds and their habitats.
If successful, the move might also solve the mystery of the whereabouts of the missing birds, officials said.
Translated by Jake Chung, Staff Writer