The Reindeer's story: How our No.1 Christmas animal is suffering

As every child knows, Father Christmas' sleigh is pulled by a small herd of reindeer, led by Rudolph with his red nose. What is less well-known is that Rudolph was only dreamt up in 1939 and until 1822 reindeer were just an obscure kind of deer living in Lapland. Unfortunately for Rudolph and his ilk, real wild reindeer are under threat. To add insult to injury, according to some research published this month, female reindeer are making such bad choices during the mating season, they could be helping speed up their own demise.

The somewhat bizarre idea of reindeer pulling a portly man in a beard on a flying sleigh was dreamt up by the poet Clement C Moore in a poem created for his children. Rudolph was not one of those eight reindeer but was the creation of writer Robert May, who was commissioned to write a Christmas story for the US department store Montgomery Ward, in 1939. In the first year alone, 2.5 million copies were given away to shoppers and Rudolph took his first, flat-footed steps to fame.

Although reindeer are now mainly confined to Russia and Norway, they used to occur in northern England and Scotland. The Vikings are thought to have hunted them, as did the Earl of Orkney 800 years ago. A small, free-ranging herd has been reintroduced to the Cairngorms, though. They were brought over by Mikel Utsi in the 1950s. Utsi, who was originally from Lapland, thought the Cairngorms reminded him of home. Indeed, the Cairngorm National Park is the UK's only remaining remnant of Arctic tundra. Originally, Utsi believed they might prove to be a good source of meat. Now the Cairngorm Reindeer Company has 130 reindeer, none of whom are eaten.

"It's a rather special herd," says Tilly Smith, the company director. "Once people have come and visited them, and once they've all got names, it's a bit difficult to eat them." Smith had written to Utsi's wife asking if she could help out with the reindeer as a volunteer after she had finished her zoology degree. "I have always been fascinated by deer," she says. "My dad loved muntjac deer, which were introduced by the Duke of Bedford. He did a lot of the early work on their natural history and I helped him."

When Tilly arrived, Alan Smith had been working as the reindeer keeper for three years. "The keeper was good looking, the mountains stunning, the reindeer pretty," laughs Tilly. Two years later, Tilly and Alan married. The Smiths took over the running of the company when Utsi's widow died; 25 years later, they're still looking after their deer.

Reindeer are thought to have been the first hoofed animal to have been domesticated around 30,000 years ago in Scandinavia - and today substantial herds of domesticated animals still exist. Their milk is prized because it's so rich in fat - whales and seals have a similarly high amount. The meat is widely eaten and their hides are used for many purposes - such as providing skid-free soles for shoes. Reindeers' economic importance and their curiosity has led to their decline as they are extensively hunted. In the 19th century, wild reindeer went extinct in Finland and although some have migrated back into the country, their numbers remain small. In southern Norway, there are only 20 small populations with a total number of 40,000 deer.

The problem, according to Dr Oystein Holand, a reindeer expert from the Norwegian University of Life Sciences, near Oslo, is a combination of habitat fragmentation and habitat destruction, as people move ever further into the mountains, cutting roads through the forests and building new houses. The remaining wilderness is becoming increasingly industrialised due to oil, gas and timber extraction. "Climate change is also a major factor," says Holand. "As a result of global warming, the timber line is creeping up and the alpine area is being reduced, so reindeer are increasingly vulnerable."

Holand has been studying the reproductive dynamics of a small herd of Finnish reindeer for a number of years. His latest paper focused on female mate choice. Male deer fight for dominance and the victor will mate with as many females as possible. However, even in species that appear male dominated, there is almost always a large element of female choice. What Holand wondered was whether females were able to discern whether they were genetically related to males or not before they mated with them. Unfortunately, females don't seem to be able to make this fine level of discrimination and will not only fail to choose to mate with males from other reindeer groups, but will mate with related males.

The situation has been worsened because of hunting. Most wild reindeer herds are female dominated because in the Seventies males were traditionally removed to increase the number of females in the herd. It was thought that this would boost the number of young and result in higher deer numbers, which would benefit hunters. The consequence, though, is that the deer are in grave danger of inbreeding. "We know from studies of other wild populations that inbreeding has a detrimental effect," says Holand, "Many of our wild populations only have 200-500 individuals and when the number is that low, inbreeding can have a big impact. Inbreeding reduces their ability to survive."

A conservation programme has not yet been launched, but the Norwegian directorate of wildlife management has completed a proposed action plan to help safeguard at least five-to-six of the larger populations by preserving their habitat and reducing the skewed nature of the herds, so that the sex ratio becomes more balanced. Itsuggests that big, old males should be reintroduced to each herd.

In the wild, reindeer mainly eat lichen, but they are not averse to eating fungi and, in particular, the red-and-white-flecked fly agaric, which has hallucinogenic properties. The Reindeer Company had one deer, Frostie, who appeared to be intoxicated from late summer onwards. The first year Frostie staggered around, walked sideways and kept falling over, the Smiths thought it was simply his quirky character. By the second year, they had begun to wonder if Frostie was partial to the toadstools.

As for Rudolph, his transition from the ugly duckling of the reindeer world to the ninth member of the sleigh-pulling team was down to a song written by Johnny Marks and recorded by Gene Autry in 1949. One question that Tilly Smith is annually asked is what sex Rudolph is. It's not obvious: unlike most deer species, both sexes have antlers. But by Christmas the males, who only need theirs for the rut, will have lost theirs. Female reindeer, at this time of year, are likely to be pregnant and not being as strong as males, are not that good at sleigh-pulling. So Rudolph the red-nosed reindeer is likely to be a castrato.

'The Real Rudolph: A Natural History of the Reindeer' by Tilly Smith, 2006, Sutton Publishing, £14.99; the Cairngorm Reindeer Centre, Aviemore, Scotland, ( www.reindeer-company.demon.co.uk) 01479 861 228)

The reindeer's story

There are 40 species of deer; reindeer are the only Arctic species.

The reindeer's coat is one of the thickest and densest of any animal. They are so well-insulated that even when lying in the snow, they don't give off any heat and thus don't melt the snow.

Their hooves are wide to stop them from sinking into the snow.

During the winter, they mainly eat reindeer moss and lichen; in summer their diet broadens to include herbs, grasses, cotton grass, leaves, twigs, bulbs, shoots, and, of course, fungi.

Reindeer have been painted on cave walls since the Stone Age.

As well as being hunted by humans, they are also predated by wolves.