Saving the saiga
The saiga, a species of antelope native to Central Asia, once roamed the vast grasslands of this region in enormous herds, many millions strong. Regrettably, such spectacular sights are a thing of the past. Today, the saiga is largely confined to a single country: Kazakhstan. This country is estimated to be home to well over 90% of the global saiga population, with Russia, Mongolia and Uzbekistan accounting for the rest.
The saiga is perfectly adapted to the tough conditions of the remote wilderness of the steppes of Central Asia. One such adaptation is its bizarre bulbous nose, which enables the animal to survive the extreme seasonal temperature swings of the region. The swollen nostrils of the nose serve several purposes: they filter out dust and cool the blood during hot, dry summers, and they warm the cold air before it enters the saiga's lungs in winter. Other seasonal adaptations include a heavy winter coat that the saiga sheds when the weather warms up.
Despite these superb adaptations to harsh conditions, the saiga has no defence against the threats posed by humans. It was almost driven to extinction by hunters in the 19th century. Legal protection ensured its survival for a while, and numbers steadily recovered throughout most of the 20th century. But the respite was only temporary. In the ten years following the break-up of the former Soviet Union in 1991, over 95% of the global population was lost – one of the fastest examples of species loss ever recorded for a mammal.
The dramatic decline during this decade was due to illegal poaching on an industrial scale. Male saiga are a particular target, because their horns are highly prized by traditional medicine practitioners. Poaching reached epidemic levels after misguided conservationists tried to relieve the pressure on threatened African rhinos by actively encouraging the use of saiga horns in traditional medicine as an alternative to those of rhinos. Male saiga were almost wiped out, leading to a population crash from which the species has been struggling to recover ever since.
Another threat to the survival of the saiga is loss of habitat, as a result of agricultural expansion and human settlement. Physical barriers such as railways, pipelines and fences can block the seasonal migration routes of this transboundary species. In the worst cases, herds may starve to death after being trapped.
Then there is the risk of disease. In 2015, an outbreak of haemorrhagic septicaemia, caused by the normally harmless bacterium Pasteurella multocida, killed over 75% of the global adult saiga population in just three weeks. In 2017, 60% of the Mongolian saiga population – a subspecies found nowhere else in the world – was killed by a virus that spilled over from livestock. These so-called mass mortality events represent an unpredictable and serious threat to the species.
Climate change poses a further threat. Although well adapted to cold winters and hot summers, saiga struggle to cope with temperature extremes and unpredictable fluctuations in climate. Experts believe that unusually warm weather may have triggered the 2015 mass mortality event. The steppe region has also become increasingly arid in recent years, and many of the smaller streams that the species normally depended on have dried up and vanished.
Recent efforts to save the saiga have been spearheaded by the Altyn Dala Conservation Initiative, a project led by the Association for the Conservation of Biodiversity of Kazakhstan, working in partnership with the Kazakh government's Committee for Forestry and Wildlife, Frankfurt Zoological Society and Fauna and Flora, an international conservation charity. Its purpose is to protect and restore Kazakhstan's steppe, semi-desert and desert ecosystems and the many species they support, including the critically endangered saiga. In 2022 the United Nations recognised the initiative as a World Restoration Flagship project, an accolade reserved for the ten best examples of large-scale ecosystem restoration around the globe.
So, how many saiga are there now? By 2000, the global saiga population had hit an all-time low of just 21,000 individuals. There was some recovery in the first decade of the new millennium but this was then crushed by devastating mass mortality events that saw the loss of hundreds of thousands of the species. But thanks to the intervention of the Altyn Dala Conservation Initiative, the most recent episodes in the ongoing story of the saiga have been relatively uplifting. Three years ago, the Ustyurt Plateau population in Kazakhstan experienced its largest mass birth of saiga calves in many years. An aerial census two years ago recorded an estimated 842,000 saiga across Kazakhstan as a whole, and according to an aerial survey earlier this year, the saiga population in Kazakhstan now exceeds 1.9 million. The world's strangest-looking antelope remains critically endangered, but the direction of travel is positive.
Complete the notes below.
Choose ONE WORD ONLY from the passage for each answer.
Write your answers in boxes 1-7 on your answer sheet.
关键字:adaptations, bulbous nose, keep…out
答案位置:第 2 段倒数第 4 行
题解:题目:拥有一个又大又鼓的鼻子,鼻孔明显膨大,可 以把 挡在外面
解析:本题前 3 道都在讲赛加羚羊的适应特征(adaptations)。文中提及它们的 bulbous nose 时原词出现,并指出,在炎热干燥的夏季,鼻子能够过滤掉灰尘(filter out dust)并降低血液温度。此处 filter out 即题目中的 keep…out。因此答案为 dust。
关键字:lower… temperature of its, summer
答案位置:第 2 段倒数第 3 行
题解:题目:夏天能降低它的 温度
解析:同上题,在炎热干燥的夏季(summers),鼻子可以过滤掉灰尘,并降低血液温度(cool the blood),此处 cool 即题目中 lower…temperature 的意 思。因此答案为 blood。
关键字:grows a thick, winter,loses in spring
答案位置:第 2 段倒数第 2 行
题解:题目:冬天会长出厚厚的 ,它到春天会脱落
解析:文中提及,其他季节性适应特征还包括厚重的冬季皮毛(a heavy winter coat),而当气候回暖,赛加羚羊会褪掉这些毛(sheds when the weather warms up)。 此处 heavy 是题目中 thick 的同义替换, 而 winter 与题目中的 in winter 算是原词复现。因此答案为 coat。
关键字:reasons, decline, poaching,especially for, male
答案位置:第 4 段第 2 行
题解:题目:种群数量减少的原因——偷猎,尤其是偷猎雄 性赛加羚羊的
解析:文中提及赛加羚羊数量急剧下降(dramatic decline)时指出,是由于大规模非法偷猎(due to illegal poaching)造成的。之后解释了为何会雄性(male)赛加羚羊尤其成为目标(particular target), 因为它们的角(horns)在传统医学从业者眼中很有价值(highly prized)。此处的 particular target 即题目里 poaching, especially for 的同义替换,而它们的 horns 有价值所以惨遭盗猎,符合题目中缺失成分。 因此答案为 horns。
关键字:reduction, size, saiga's
答案位置:第 5 段第 1 行
题解:题目:赛加羚羊的 规模缩减
解析:审题须知要找的是什么的规模变小了。文章提及威胁赛加羚羊生存的另一个原因时指出,栖息地丧失(loss of habitat)是赛加羚羊生存所面临的另一个威胁,这主要是由农业扩张和人类定居造成的。loss of habitat,即 habitat 变小了(或消失了),符合题目中的 reduction in the size。因此答案为 habitat。
关键字:loss of access to,use for migration
答案位置:第 5 段第 3 行
题解:题目:无法使用他们用来迁徙的
解析:文中提及如铁路、管道和围栏等人为物理屏障 (physical barriers),会阻碍这种跨境迁徙物种的季节性迁徙路线(block…migration routes)。此处的物理 barriers,也就是看得见摸得到的屏障,连同 block 一起,都对应着题目中 loss of access to 的这个意思。因此答案为 routes。
关键字:climate change, causing, disappearance, relied on
答案位置:第 7 段倒数第 2 行
题解:题 目:气候变化导致了赛加羚羊赖以生存的 消失
解析:本题只要查找它们赖以生存的什么由于气候变化消失了。文中提及 climate change 时是在描述危机加剧赛加羚羊的生存难度(a further threat),而后具体举例说明了近年来,草原地区愈发干旱,许多这类动物过去赖以生存的小溪(streams…the species normally depended on)已经干涸并消失(dried up and vanished)。此处的 the species 根据上下文就是在说赛加羚羊,而 depended on 对应题目中的 relied on,vanished 对应题目中的 disappearance。因此答案为 streams。


