Skip to content

Christmas: A Natural History

Snowy woods

If you look beyond the tinsel, fairy lights and last-minute shopping for presents, there are actually a lot of natural elements to traditional Christmas celebrations. Some of these were appropriated from older, pagan beliefs by Christianity, while others are much more recent in origin. So, we thought we’d delve into the beginnings of some of these wildlife connections with Christmas, a natural history


One of the first things many of us think of when we think of Christmas is the robin. The link between cards and robins began in Victorian times, when postmen wore red tunics and became known as ‘robin redbreasts’. It had long been a custom to send a Christmas letter at this time of year, and from the second half of the 19th century, Christmas cards rose in popularity. The postmen delivering these items were therefore an important part of Christmas. Their whimsical representation as robins on cards was a logical development. There are also older connections. One story explains that the bird got its red breast while fanning the flames of a fire in the stable where the baby Jesus lay.

Christmas Natural history robin
The robin’s association with Christmas began in the Victorian era

Robins are one of our most familiar birds due to their confiding nature. This is largely down to the fact that, as woodland birds, they follow bigger animals like wild boar as they root up bulbs and other food. The robin then gets an easy meal from the worms and grubs brought to the surface. In the UK, they have learnt to do the same with gardeners. On the Continent, where humans have often trapped and hunted small birds, they are much more wary, and the same relationship hasn’t arisen. Robins are even more visible in the winter. This is because thousands of birds from mainland Europe arrive to take advantage of our slightly warmer winters.

Christmas Trees

The decorated Christmas tree tradition began in the 16th century in what is now Germany. In the UK, we usually credit Queen Victoria’s German husband Prince Albert with introducing the practice. However, George III’s wife Charlotte was probably the first royal to put up a tree in the UK. Prince Albert certainly popularised the tradition, though. Trees were once decorated with fruit, nuts and sweets or cookies, but the trend for ornaments gradually took hold. A more recent tradition relates to the UK’s support of Norway during WWII. To say thank you for this help, Norway has been sending huge Christmas trees every December since 1947 for display in Trafalgar Square and Edinburgh.

Christmas trees Christmas, a natural history
Prince Albert popularised the tradition of putting up a Christmas tree in the UK

Appropriately enough in light of this, Norway spruce is one of the most popular species for real Christmas trees. This might be because they look like everyone’s idea of the perfect Christmas tree with their triangular shape. The species may have grown in the UK before the last ice age. Now, although non-native, it is extremely widespread across the country due to its importance in the forestry industry. As well as for building and furniture, the wood is often used in paper production. It is also supposed to produce a good tone when used for stringed instruments.

Holly and Ivy

Holly and ivy are linked to Christmas in the carol ‘The Holly and the Ivy’, which probably dates from about 1800. However, the two have been connected to this time of year for much longer than that. Like many other evergreen plants, in pre-Christian times holly was used to represent rebirth and eternal life at the winter solstice. It also warded off evil spirits and stood for fertility. The Romans associated it with the god Saturn so used it around the festival of Saturnalia in December. Many pagan traditions were adopted and modified to fit Christianity. Holly is no exception, and its prickles came to stand for Christ’s crown of thorns and the berries for his blood. In German, it is known as ‘christdorn’ meaning Christ thorn. Ivy has similar connections to warding off evil and the devil. As it still has green leaves throughout the winter, it also symbolised rebirth.

Holly Christmas: a natural history
Pre-Christian societies revered holly as a symbol of rebirth

Interestingly, you may notice that some holly trees have prickly leaves lower down, and almost smooth ones higher up on the plant. A study from 2012 found that they are able to react to herbivores like deer browsing on them by producing prickly leaves to defend themselves where animals can reach them. Above the browse height, they don’t need to respond in the same way. Ivy, meanwhile, flowers late in the year meaning it provides nectar for pollinators when nothing else is available. It is also acts as an important winter shelter for a range of organisms including bats, mice, voles, birds and invertebrates.

Ivy provides food and shelter throughout the winter for a range of animals and birds


Mistletoe is another plant whose evergreen quality linked it to fertility in pagan cultures, including Celtic druidic tradition. In addition, there are stories in Norse mythology linking it to the goddess of love, Frigg. No one is sure how the more recent tradition of kissing under a sprig of the plant at Christmas began. By the 18th century, though, it was popular amongst the servant classes and subsequently spread to the more well-to-do. Some practices involved a simple kiss under a sprig, while others allowed a kiss for each berry plucked from a plant. Being evergreen, the plants were easy to find in the winter when the deciduous trees they grew on lost their leaves.

Mistletoe a natural history
Mistletoe forms characteristic clumps on deciduous trees

The European mistletoe is a hemi-parasitic plant, which means they are able to photosynthesise but gain other nutrients and water from a host plant. Mistletoe usually grows on broad-leaved deciduous trees such as apples, oaks, hawthorns, willows and poplars. The plant is easy to identify with its pairs of propeller-like leaves and creamy white berries. These berries are toxic to humans and many other species, but some birds are immune. The mistle thrush is one such bird, hence its name as they readily eat the berries.


Reindeer are another fairly recent addition to Christmas imagery. Until Christmas became much more than just a religious festival in the 19th century, connections with the north and snow probably wouldn’t have been as central as they are now to Northern Hemisphere inhabitants’ idea of Christmas. However, in 1821, American writer William Gilley, who had heard about reindeer from his mother, included them pulling Santa’s sleigh in a children’s story. Two years later, the image was developed further in the poem, ‘A Visit from St Nicholas or ‘The Night Before Christmas’, usually attributed to Clement C Moore. The poem is our first introduction to the reindeer names Dasher, Dancer, Prancer, Vixen, Comet, Cupid, Donner and Blitzen. And Rudolph? He came along even later. created in 1939 by advertiser Robert L May for a department store storybook.

Reindeer Christmas a natural history
Most reindeer in Europe are domesticated

Reindeer and caribou are technically the same species. We usually refer to European animals as reindeer and North American ones as caribou. Reindeer usually also refers to domesticated animals rather than wild caribou. Humans domesticated them at least two thousand years ago and they are still vital to groups like the Sami of northern Europe. As well as pulling sleds, they provide food and material for making clothing, tools and vessels. Wild caribou in North America, meanwhile, undertake huge seasonal migrations between their summer and winter ranges. Incredibly, scientists revealed in 2012 that some real reindeers, like the fictional Rudolph, do indeed have red noses. A dense network of blood vessels near the surface of their noses’ skin apparently helps them regulate body temperature in extreme conditions.

Birds in The Twelve Days of Christmas

Theories about the origin of the carol ‘The Twelve Days of Christmas’ are as varied as versions of the song itself. The song was first published in England in the late 18th century but it is probably older. Its cumulative style suggests it originated as some sort of children’s memory game. The version we are now most familiar with here refers to a number of birds, some domestic, some wild. Other versions, though, include hares a-running and badgers baiting at different points of the song. The four calling birds used to be ‘colly’ birds which may be a dialect word for black or may instead refer to ‘coloured’ birds of some sort. There has been much debate as to whether the various gifts given actually mean something or if they were chosen for no real reason other than that they worked in a rhyme.

Turtle dove Christmas, a natural history
Turtle doves were once common farmland birds but are now in huge decline

Turtle doves appear in most versions of the song. However, by Christmas this pretty migratory pigeon is long gone from the UK and spending the winter in Africa. Visiting from April to September each year, it is the UK’s fastest declining bird species and is critically endangered. They have suffered a staggering 98% population fall since 1970, with just 2,100 breeding pairs left in the UK. Once common across rural England, they are now easiest to see in East Anglia and Southeast England. Reasons for the rapid drop in numbers probably include habitat loss and food shortages during the breeding season combined with high levels of hunting in some countries as they migrate. Despite its increasing rarity, millions are killed legally across Europe each year, in addition to the many caught illegally.

Happy Christmas!

However you celebrate at this time of year, Purple Plover wishes you a peaceful and joyous festive season!