论文部分内容阅读
AT the Crested Ibis Natural Conservation Centers in Yangxian and Ningshan counties of Shaanxi Province， nesting pairs of crested ibis are busy raising their young under the watchful eyes of trained staff.
Thirty-two years ago， the crested ibis， whose domain once ranged across China， Japan， Korea and Russia， was thought to be extinct. In 1981， a flock of seven of the birds was spotted in Shaanxi Province， much to the joy of the country’s – and the world’s – ornithologists. Local authorities seized on the discovery and began a breeding program. Today， the crested ibis population exceeds 1，800. It’s a remarkable success story – and a lucky escape.
Recovery from the Brink
In 1981， Liu Yinzeng， a research fellow from the Institute of Zoology of the Chinese Academy of Sciences， came to Yangxian County to look for crested ibis. Lu Baozhong， a newly enrolled staff member at the Yangxian County Forestry Bureau， voluntarily accompanied Liu on his search. Neither believed the extinction rumors.
On May 23 of that year， Liu and Lu made their discovery. They spotted seven ibises in Yangxian County’s Yaojia Valley.
Since then， Lu has formed an unbreakable bond with his favorite bird. In the beginning， in order to protect the seven birds， Lu led a team to set up an observation network that covered the whole valley. They spread butter on tree trunks and set knife traps to ward off snakes and yellow weasels. They hung a net beneath each of the Ibises’ nests to prevent newly hatched chicks from falling out. They did everything they could to guarantee the continued breeding and eventual recovery of the wild population.
In order to ensure the safety of the ibises’ food sources， the government of Yangxian County asked local farmers to stop using pesticides and chemical fertilizers in their paddy fields， where the birds would often venture to find food. In addition， the government set aside an expanded area of natural wetlands and paddy fields with winter ponded water for the birds. Locals have subsequently restored the wetlands to over 233 hectares and the paddy field areas with winter ponded water to about 100 hectares. The restored habitat of the crested ibis now includes recently reinvigorated mountainous forestlands of over 2，667 hectares， with 3，000 tall trees. Thanks to such efforts， the numbers of wild crested ibis have grown every year since the mid-1980s.
In order to research and monitor age structure and migration patterns， the Crested Ibis Observation Center in Shaanxi Province has put digitally imprinted bands on the legs of birds that have been released to the wild since 1987. Since 2000， the annual growth of the population has been over 30 percent. The number of fledglings released into the wild was over 100 in 2004； in 2008 the figure had reached 200， and in 2011 it stood at 250. Assisted Propagation
International conventions on protecting endangered wildlife stipulate efforts to both protect existing wild crested ibises and introduce artificial propagation to help increase their numbers.
In February 2002， an artificial propagation base for the crested ibis was established in Louguantai National Forest Park in Shaanxi Province. Thirty pairs were transferred from Yangxian County to be raised at the base. In that year， 26 ibis chicks were hatched. Following the first year success， the base conducted a series of experiments to enhance the birds’ fertility.
Today the record for one pair stands at four chicks.
By May 2013， the base had seen the hatching and successful raising of over 300 chicks. It is the largest artificial reproduction base for crested ibis in the world.
From 2004 to 2006， the National Nature Reserve for Crested Ibis and the National Bird Banding Center of China cooperated in a groundbreaking experiment in Huayang Town of Yangxian County to set artificially bred crested ibis free into the wild. In two years the team set 23 free， 13 of which survived.
In 2006， the birds that had earlier been set free paired off with wild birds for the first time. So far such pairings have produced 40-odd chicks.
On May 31， 2007 staff at a base in Ningshan County’s Zhaigou Village， Shaanxi Province set 26 artificially bred ibises free. Beforehand the team had done extensive work acclimatizing them to the conditions they would face in the wild. The birds have since paired off into nine couples， built eight nests and raised 13 chicks.
To better acquaint ibises raised in conservation centers with survival skills for the wild – and to study the birds themselves – the Shaanxi provincial government created a 3，600-square-meter reintroduction center in Huayang Town in 2010. Ibises there are trained to forage and feed for themselves– essential skills once they enter the wild. An effective system is now fully established at the center that trains up birds before setting them free.
Breeding in Foreign Countries
On the verge of extinction a mere 32 years ago， the population of crested ibis has ballooned – by a multiple of 130 since 1981. The number of institutes devoted to the bird’s continued survival has risen， and not just in China. The range of wild ibis has expanded to cover much of its habitat in former times. Some of the birds have even been spotted in Japan and South Korea.
In 1998， Jiang Zemin， then president of China， visited Japan. He brought with him a pair of crested ibis as gifts. Four months later a male chick was hatched and given the name Youyou. In 2000， Zhu Rongji， then premier of China， visited Japan and presented a female crested ibis named Meimei. Youyou and Meimei were joined by another pair in April of 2007， brought by then Chinese premier Wen Jiabao. Continued transfer between the nations should ensure the gene pool diversity of the Japanese crested ibis population.
Thirty-two years ago， the crested ibis， whose domain once ranged across China， Japan， Korea and Russia， was thought to be extinct. In 1981， a flock of seven of the birds was spotted in Shaanxi Province， much to the joy of the country’s – and the world’s – ornithologists. Local authorities seized on the discovery and began a breeding program. Today， the crested ibis population exceeds 1，800. It’s a remarkable success story – and a lucky escape.
Recovery from the Brink
In 1981， Liu Yinzeng， a research fellow from the Institute of Zoology of the Chinese Academy of Sciences， came to Yangxian County to look for crested ibis. Lu Baozhong， a newly enrolled staff member at the Yangxian County Forestry Bureau， voluntarily accompanied Liu on his search. Neither believed the extinction rumors.
On May 23 of that year， Liu and Lu made their discovery. They spotted seven ibises in Yangxian County’s Yaojia Valley.
Since then， Lu has formed an unbreakable bond with his favorite bird. In the beginning， in order to protect the seven birds， Lu led a team to set up an observation network that covered the whole valley. They spread butter on tree trunks and set knife traps to ward off snakes and yellow weasels. They hung a net beneath each of the Ibises’ nests to prevent newly hatched chicks from falling out. They did everything they could to guarantee the continued breeding and eventual recovery of the wild population.
In order to ensure the safety of the ibises’ food sources， the government of Yangxian County asked local farmers to stop using pesticides and chemical fertilizers in their paddy fields， where the birds would often venture to find food. In addition， the government set aside an expanded area of natural wetlands and paddy fields with winter ponded water for the birds. Locals have subsequently restored the wetlands to over 233 hectares and the paddy field areas with winter ponded water to about 100 hectares. The restored habitat of the crested ibis now includes recently reinvigorated mountainous forestlands of over 2，667 hectares， with 3，000 tall trees. Thanks to such efforts， the numbers of wild crested ibis have grown every year since the mid-1980s.
In order to research and monitor age structure and migration patterns， the Crested Ibis Observation Center in Shaanxi Province has put digitally imprinted bands on the legs of birds that have been released to the wild since 1987. Since 2000， the annual growth of the population has been over 30 percent. The number of fledglings released into the wild was over 100 in 2004； in 2008 the figure had reached 200， and in 2011 it stood at 250. Assisted Propagation
International conventions on protecting endangered wildlife stipulate efforts to both protect existing wild crested ibises and introduce artificial propagation to help increase their numbers.
In February 2002， an artificial propagation base for the crested ibis was established in Louguantai National Forest Park in Shaanxi Province. Thirty pairs were transferred from Yangxian County to be raised at the base. In that year， 26 ibis chicks were hatched. Following the first year success， the base conducted a series of experiments to enhance the birds’ fertility.
Today the record for one pair stands at four chicks.
By May 2013， the base had seen the hatching and successful raising of over 300 chicks. It is the largest artificial reproduction base for crested ibis in the world.
From 2004 to 2006， the National Nature Reserve for Crested Ibis and the National Bird Banding Center of China cooperated in a groundbreaking experiment in Huayang Town of Yangxian County to set artificially bred crested ibis free into the wild. In two years the team set 23 free， 13 of which survived.
In 2006， the birds that had earlier been set free paired off with wild birds for the first time. So far such pairings have produced 40-odd chicks.
On May 31， 2007 staff at a base in Ningshan County’s Zhaigou Village， Shaanxi Province set 26 artificially bred ibises free. Beforehand the team had done extensive work acclimatizing them to the conditions they would face in the wild. The birds have since paired off into nine couples， built eight nests and raised 13 chicks.
To better acquaint ibises raised in conservation centers with survival skills for the wild – and to study the birds themselves – the Shaanxi provincial government created a 3，600-square-meter reintroduction center in Huayang Town in 2010. Ibises there are trained to forage and feed for themselves– essential skills once they enter the wild. An effective system is now fully established at the center that trains up birds before setting them free.
Breeding in Foreign Countries
On the verge of extinction a mere 32 years ago， the population of crested ibis has ballooned – by a multiple of 130 since 1981. The number of institutes devoted to the bird’s continued survival has risen， and not just in China. The range of wild ibis has expanded to cover much of its habitat in former times. Some of the birds have even been spotted in Japan and South Korea.
In 1998， Jiang Zemin， then president of China， visited Japan. He brought with him a pair of crested ibis as gifts. Four months later a male chick was hatched and given the name Youyou. In 2000， Zhu Rongji， then premier of China， visited Japan and presented a female crested ibis named Meimei. Youyou and Meimei were joined by another pair in April of 2007， brought by then Chinese premier Wen Jiabao. Continued transfer between the nations should ensure the gene pool diversity of the Japanese crested ibis population.