Will Santa be able to take to the skies this year? Global warming is being blamed for shrinking reindeers

The average weight of reindeer in northern Norway has decreased since 1990s[CN]

在北挪威，麋鹿的平均体重自20世纪90年代起就开始急剧下降。

Once-reliable snows fall more often as rain that can freeze into a sheet of ice[CN]

曾经稳定的降雪下得更频繁，雨水更多的固化成冰。

This makes it harder for the herbivores to reach plant food in the winter
[CN]

这样一来，这些草食动物冬天就找不到足够的食物了。

The average weight of adult reindeer on Svalbard, a chain of islands north of Norway, has fallen to 48 kg (106 lb) from 55 kg (121 lb) in the 1990s as part of sweeping changes to Arctic life as temperatures rise (stock image)
[CN]

北挪威Svalbard群岛上，成年麋鹿的平均体重自20世纪90年代起，从55公斤（121磅）降到48公斤（106磅），一切都是因为气温上升，北极圈的动物生活彻底改变。

Less chilly winters mean that once-reliable snows fall more often as rain that can freeze into a sheet of ice, making it harder for the herbivores to reach plant food[CN]

冬天没那么寒冷，就意味着曾经稳定的降雪下得更频繁，雨水更多的固化成冰。这样一来，这些草食动物冬天就更难足够的食物了。

Santa may have trouble taking to the skies this year, as it appears that reindeer are shrinking in the Arctic near the North Pole.[CN]

今年圣诞老人难飞空中，只因北极地区变暖，圣诞驯鹿锐减。

Researchers say that the animals are shrinking in a side-effect of climate change that has curbed winter food for the animals. [CN]

专家指出，麋鹿的锐减正是全球气候变暖的副作用，抑制了动物冬天食物的生长。

The average weight of adult reindeer on Svalbard, a chain of islands north of Norway, has fallen to 48 kg (106 lb) from 55 kg (121 lb) in the 1990s as part of sweeping changes to Arctic life as temperatures rise. 
[CN]

北挪威Svalbard群岛上，成年麋鹿的平均体重自20世纪90年代起，从55公斤（121磅）降到48公斤（106磅），一切都是因为气温上升，北极圈的动物生活彻底改变。

The research comes from ecologists at the James Hutton Institute in Scotland. 

Professor Steve Albon, who led the study, said: 'Warmer summers are great for reindeer but winters are getting increasingly tough.'

Less chilly winters mean that once-reliable snows fall more often as rain that can freeze into a sheet of ice, making it harder for the herbivores to reach plant food. 

Some reindeer starve and females often give birth to stunted young.

In summer, however, plants flourish in a food bonanza that ensures healthy females are more likely to conceive in autumn - a pregnancy lasts about seven months. 

The wild herd studied had expanded to about 1,400 animals from 800 since the 1990s.

'So far we have more but smaller reindeer,' Professor Albon said of reindeer on Svalbard, about 800 miles (1,300 km) from the North Pole. 

The rising population also means more competition for scarce food in winter. 

Arctic temperatures are rising faster than the world average amid a build-up of greenhouse gases in the atmosphere.

Most studies of global warming around Svalbard have focused on polar bears that hunt seals at sea, rather than year-round land residents led by reindeer, Arctic foxes and Svalbard rock ptarmigan birds.

Arctic fox numbers have risen slightly because they thrive in severe ice winters by scavenging dead reindeer, said Eva Fuglei, a researcher at the Norwegian Polar Institute and the Fram Centre who was not involved in the reindeer study.

'All the weak reindeer die - the sick, the elderly and calves,' she said. 

But that means foxes struggle to feed the next winter because only the fittest adult reindeer have survived.