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Content Updated: 7th December 2014

SEASONAL UPDATE: December 2014

Frosted Winter Leaves

Welcome to December and the final throes of 2014. After an often unsettled and mild month (not withstanding a couple of clear nights and early frosts), we finished November with temperatures in the low to mid-teens Celsius over much of the UK, which is just above the seasonal average of 9 Celsius (48 Fahrenheit). This mild weather appears to have confused some species and I’ve seen reports of mating doves, emerging tulips and mating dragonflies and bees last week, as well as frogspawn and, on the way home from work on Friday I encountered a small swarm of flying insects. The forecast for the month ahead, if you broadly ignore the hyperbole that the Express have been publishing over the past week-or-so, is that temperatures will be around, or slightly below, the seasonal average for the time of year. The first week in December heralded a brief period of “Returning Polar maritime” (basically, quite cold) air for the whole of the UK, providing a beautifully cold, crisp morning on Saturday. The Jet Stream is, however, currently sinuating in the North Atlantic, which will bring some very strong winds over Britain later next week, although the temperatures are set to remain fairly low, bringing the chance of snow on higher ground and wintery showers at lower levels.

As regular readers will know, for the last couple of years I have been featuring a species every month, trying to provide a window into the worlds of some of the fascinating animals with which we share our country. This year, I’ve covered tawny owl courtship (January), spawning behaviour of frogs and toads (February), brown hare boxing (March), the mole (April), slowworm biology (May), baby deer (June), glowworms (July), the stoat (August), common shrews (September), the truth about spiders (October), and wood mice (November). Now that the festive season is upon us, it seemed fitting to cover something vaguely 'Christmas-y'. Last December I featured robins, but this year I wanted to take a closer look at an animal that millions of children all over the world are familiar with, and yet many have never seen: the reindeer. Before we go on to that, however, let’s take a quick look at what’s happening in the natural world this month.

Mammals: Being the start of winter, December is a month in which many mammals venture out less, with some choosing to opt out of the season altogether. Our bats, dormice and hedgehogs are the only British mammals that truly hibernate (if you’re wonder what makes hibernation ‘true’, it’s all to do with lowering body temperature and reducing biochemical processes – read more here). With that in mind, please check any piles of garden rubbish before having a bonfire. Such spots make ideal hedgehog hibernation venues and an untold number are killed in bonfires every year. Furthermore, please keep an eye out for hedgehogs continuing to visit your garden in this month. Each autumn many hedgehogs give birth to late litters and these youngsters don’t have sufficient time to reach the minimum weight of 700g needed to see them through hibernation. If you find a hedgehog in your garden, particularly if it is small or out during the day, please check out my Caring for Hedgehogs article.

Hedgehogs may be taking things to extremes by skipping winter altogether, but many other mammals are also much less active than usual. Badgers, for example, venture out of the sett much less during the winter than other seasons although they don’t hibernate. Similarly, the rutting action has died down among our deer and the males are now rather more sociable as they spend the winter feeding together in bachelor groups. Roe deer will soon start to cast and re-grow their antlers and can often be seen feeding out in the open in large groups during December.

Chinese Water Deer in BedfordshireThe fact that some mammals are slowing down doesn’t mean that all are. Indeed, we’re now arriving at the busiest time of year for our foxes - busiest in the sense of the greatest fluidity in the UK fox population, with animals moving around more than in any other season. Winter is the fox mating season and this month you’ll start seeing foxes moving around in pairs. The dog fox doesn’t leave his vixen’s side as he waits for her to come into season. Once she has finished her estrus and he has mated with her, however, he’s off, ranging widely to look for other receptive females. During this period, foxes are very vocal, and there are fewer leaves on the trees and bushes to muffle the sound as both sexes call to attract mates and the males fight amongst each other as they trespass on each other’s territory trying to get at vixens.

The 'teddy bear deer', more properly known as Chinese water deer (left), are also breeding during this month, and if you live in eastern England - particularly in the vicinity of the Woburn Estate, near the Broads of Norfolk or Suffolk, or in the East Midlands and Home Counties where small populations have become established following escapes from Whipsnade Zoo - you may be fortunate enough to see these fascinating little deer rut. Unlike all our other cervids (deer), Chinese water deer do not have antlers. Instead, the males possess impressive canine teeth which they use to fight each other for access to females. This species makes an interesting barking noise when disturbed that, to my ear at least, sounds very fox-like.

Birds: Our lakes and estuaries are busy at time of year with flocks of waders and ducks, many having arrived from further north and east to overwinter in the milder conditions of the UK. Keep an eye out for gadwall, teal, lapwings, snipe, and large flocks of dunlin. Estuaries and reservoirs are also good spots for swan-watching, with large aggregations of mute swans around during this month as well as some immigrant yellow-beaked Bewick and whooper swans. There are an estimated 7,000 avocets that also overwinter in Britain, with Brownsea Island and Poole Harbour being among the best spots to watch them. Similarly, our resident populations of garden birds like robins, starlings and blackbirds are augmented with migrants from continental Europe. Last Saturday, one of my local nature reserves had a count of almost 4,000 starlings. In the fields, keep an eye out for large mixed flocks of buntings and finches, including reed buntings, yellowhammers and chaffinches as well as the odd hawfinch and brambling. Winter also sees flocks of snow buntings venture along the coastline as they spread out from their normal haunts of the Cairngorm slopes.

MistletoeRaptors and owls are also prominent at this time of year. The hen harrier is a winter visitor to the West Country, southern and eastern England, central and western Wales and western Ireland. There are some resident birds, but our population is joined by immigrants from the continent during late autumn, making the chance of spotting one higher. This species can be found inhabiting lowland farmland, heathland, coastal marshes, fenland and river valleys. Here in the New Forest, the birds roost among gorse and heather stands before moving off to feed in nearby farmland. Marsh harriers, short-eared owls and long-eared owls are also more likely to be spotted during the winter, while tawny owls are frequently heard. I have seen several Facebook posts recently with people asking what owl they can hear calling in their garden. With this in mind, I will put the tawny calls up again this month to help folks out a bit. Click to listen to a clip of a calling tawny male, tawny female, and a female tawny making the 'hoo-hooo' type call as evidence that it’s not as simple as you might think to tell the sexes apart based solely on their calls! Tawnies are very vocal at this time of year as they re-establish both pair-bonds and territories after the breeding season.

Reptiles and amphibians: Despite the present mildness apparently tempting a few bold Cornish frogs into spawning, it is now generally too cold for much in the way of reptile or amphibian activity, although the odd snake or lizard may be found out basking in early winter sunshine if temperatures remain elevated. All of our reptiles and amphibians will overwinter in a torpid state - they hibernate. Snakes and lizards pass the winter underground or among the root systems of bushes and trees, while frogs, toads and newts tend to find a sheltered spot among the leaf litter or under logs. Some amphibians will hibernate at the bottom of a pond, their metabolism being sufficiently slow that they can survive on the oxygen that diffuses through the skin into the body from the water.

Invertebrates: I mentioned earlier that I walked through a cloud of flying insects on the way home the other day, and the mild weather has meant that there are still a few butterflies (particularly red admirals and peacocks) active, as well as some ladybirds and beetles, although most of the latter are now in a semi-torpid state in the leaf litter or under logs. Similarly, there are still a few spiders around, but fewer than were to be found in October. Some bees are still on the wing, particularly where ivy is still in flower, and my next door neighbour witnessed a pair of bumblebees mating in his garden on the morning of Saturday 29th November.

Plants and fungi: A walk in the woods to help settle your Christmas lunch is a fine idea, and while looking for the usual mammal and bird fauna, keep an eye out for some of the under-appreciated flora around at this time of year. Woodland mosses and lichens can be beautifully elegant, and, especially when tinged with frost, make good photographic subjects. Lichens are a fused partnership of fungus and alga. The alga photosynthesises to produce sugars (food) which the fungus absorbs, while the fungal cell protects the alga from the environment in a charming symbiosis. Also around at this time of year is the seasonally appropriate scarlet elf-cup fungus which grows from rotten wood and is widespread although not abundant in Britain. The fruiting body has a diameter of a few centimetres with a pale pinky-orange outside and a bright red inside to the cup. The velvety-soft Jew’s ear fungus is also around during this month. Also keep an eye on the bare tree tops for clumps of the evergreen parasitic plant mistletoe (right), which are very obvious and in berry during this month.

Pick of the Month for December – Reindeer (Rangifer tarandus)

Reindeer (Caribou)Most children are familiar with this deer species because of its association with Father Christmas,  Papa Noël, Santa Claus, Saint Nick, or whatever other name you know him by. Father Christmas’ sleigh is pulled by a group of eight magical flying reindeer that are, according to the poem A Visit from Saint Nicholas, commonly re-titled 'The Night Before Christmas', published by Clement Clark Moore in 1823: Dasher, Dancer, Prancer, Vixen, Comet, Cupid, Dunder (from the German meaning 'thunder' but frequently changed to Donner), and Blixem (from the German meaning 'lightning' but frequently changed to Blitzen). You might have noticed that a certain bright-nosed member of the team is missing from this list. Rudolph the red-nosed reindeer wasn’t included until 1939, when Robert May was commissioned by the Montgomery Ward chain of department stores in the USA to create a Christmas poem for a book that was to be given out shoppers at Christmas as a promotional gimmick. May apparently took inspiration from The Ugly Duckling and his own childhood experiences, during which he was often bulled for being small and shy.

Despite their place in our childhood memories, though, how much do you really know about reindeer? Was Stephen Fry correct on QI, for example, when he said that all of Santa’s reindeer were actually either females or castrated males because male reindeer lose their antlers in winter? In the article that follows I provide a glimpse into the fascinating world of the reindeer. I agree with Stefan Buczacki who wrote in his 2002 book Fauna Britannica, “Outside the month of December, most people in Britain never give the Reindeer a second thought, which is a pity because it is a remarkable beast.”

Deer that reign?
So, first things first: what are reindeer? Well, they’re large mammals that are members of the deer family (the Cervidae), the second-largest species of deer after the moose (Alces alces). They generally sport an un-spotted grey-brown coat with a lighter ash-grey belly, darker flanks and legs, a white rump, short tail, white feet and, in males, a white mane. Their winter coat tends to be lighter in colour than their summer one and is composed of dense underfur covered by thick, hollow outer guard hairs that insulate the animal and keep it dry. Reindeer have broad hooves that spread their weight, reducing the degree to which they sink in boggy and snowy ground, and that adapt to the season: foam-like pads expand in the summer to provide grip when the tundra is soft and wet, and contract during the winter, exposing the rim of the hoof to create an excellent ice-walking and snow-scraping device. The feet are also furred, which helps both to insulate and to provide grip in icy conditions. Males, called bulls, stand 100-130cm/3ft 4in.–4ft 4in. at the shoulder and weigh 110-220kg/242-485 lbs, while females, which are called cows, are smaller, standing 95-115cm/3ft 1in.–3ft 10in. at the shoulder and weighing 65-150kg/143-331 lbs. Interestingly, domestication appears to suppress growth in this species and one study found that, when freed of human interference, reindeer increased their body mass by 20-40%, bulls being more strongly affected than cows.

The origin of the name "reindeer" is obscure. It is believed to have roots as least as far back as Old Norse, translating roughly as a 'horned animal'. Scientifically, the reindeer was first formally classified in 1758 as Cervus tarandrus - meaning, roughly, 'deer of the northern tundra' - by Carl von Linné (also known as Carl Linnaeus) based on a specimen from Lapland. As our understanding of animal relationships improved, however, it became clear that the deer family required an overhaul, and species were gradually split out of the main Cervus genus. The first use of the name Rangifer appears in naturalist and spy Lieutenant-Colonel Charles Hamilton Smith’s chapter of Baron Cuvier’s 1827 publication on “The Animal Kingdom, Arranged in Conformity with its Organisation”. Smith described reindeer as being of the “The Rangiferine Group” of deer, using Rangifer as a subgenus of (grouping within) Linnaeus’ Cervus, but he didn’t go into any detail about why he thought they warranted a separate grouping. Nonetheless, Smith wasn’t alone and, in his 1901 synopsis of North American mammals, New York Museum of Natural History founder Daniel Elliot elevated Rangifer to generic status, classifying reindeer as Rangifer tarandrus. It was subsequently Opinion 91 of the International Commission on Zoological Nomenclature, the body that regulates the use of scientific names, that saw Rangifer added to the list of official generic names in October 1926. Henceforth reindeer would be known as Rangifer tarandrus and not Cervus tarandrus.

Pale Caingorm ReindeerReindeer evolved in Europe 5-6 million years ago and crossed into North America at some point during the early Pleistocene, some 250,000 years ago. Fossil evidence suggests there were reindeer in Britain at least 750,000 years ago, and their remains are known from at least 30 archaeological sites in Britain and 22 in Ireland. Dating analysis of the remains suggest that reindeer died out in Ireland around 10,250 years ago, while they hung on for longer in Britain; the youngest remains, from a site in Sutherland in the Scottish Highlands, date to 8,300 years ago. There is an account of reindeer being hunted in Caithness in northern Scotland during the 12th century, but there is no archaeological evidence to support this, and it is widely believed that these were either misidentified red deer or reindeer kept by Viking settlers. Today, only a small population of introduced animals exists in Britain, and I’ll come to that shortly. Elsewhere, reindeer are found throughout much of the northern hemisphere, although populations are now highly fragmented and the genetic purity of the few remaining wild herds has recently been called into question, with one study suggesting significant mixing of wild and domestic/semi-domestic populations in parts of Europe. They can be found from Norway across Eurasia to the east coast of Russia, but the International Union for the Conservation of Nature (IUCN) notes that wild populations are only found in Norway, Finland and Russia. Reindeer are also found in parts of North America, specifically Alaska, Canada, Washington, and Idaho, where they are called caribou, and in Greenland. The worldwide population is currently unknown, but thought to be in the region of 3.5 million in North America and 3 million in Europe. Local population surveys suggest that numbers are declining, particularly in parts of North America. They have been widely domesticated in Scandinavia and Russia for meat, milk, fur, tendons (used in stitching), antlers (used for tools and jewellery) and as beasts of burden because they can be trained to pull sleds. Indeed, reindeer are the only species of deer to have been domesticated, and some authors suggest that this was the second species to be domesticated by humans, the first being the dog.

Home sweet home
The reindeer population in Britain spends most of the year well above the treeline in heather moorland on the slopes of the Cairngorms at 400-1,300 m/1,300-4,230 ft before being brought down into lower pastures to give birth during the summer. Reindeer typically inhabit open tundra, although some populations, particularly in Finland, have adapted to mountain forests. Herds living on tundra may migrate vast distances between their inland winter feeding grounds and coastal summer feeding ones – journeys of 5,000 km/3,100 miles are known, with herds moving up to 150 km/93 miles per day. Reindeer are excellent swimmers and will readily cross rivers during their migrations – it appears they can sustain 6.5 km per hour/3.5 knots in the water and can reach 9.6 kmph/5 knots when followed by a speedboat!

I have mentioned that reindeer possess a thick double-layered winter coat and fur on their feet that act as insulation. Insulation is of paramount importance for most populations because ambient temperatures on the tundra can drop to -50 Celsius/-58 Fahrenheit during the winter. Unusually among deer, reindeer do have fat reserves, but these seem to operate more as a store of energy and vitamins and don’t appear to offer much in the way of insulation. So, in addition to their fur, reindeer also have a system of counter-current heat exchangers in their legs and noses to help prevent heat being lost to the environment. The deer’s rostrum (nose), for example, is packed with a network of turbinate bones that vastly increases the surface area of the nose. Exhaled warm, moist air passes over the turbinals where it loses heat to the blood and condenses. This heat and water is then used to warm and moisten incoming cold dry air before it gets to the lungs, thus reducing the loss of water and heat during very cold weather.

The way to a deer’s heart...
Deer are ruminants, meaning their stomachs have four chambers, and the majority of their diet consists of soft, easily digested plant material. Lichens, particularly cup lichens, Cladonia, form a significant part of the diet – although more for domestic/semi-domestic deer, which are twice as likely to eat lichens as their wild counterparts, it seems – and are eaten throughout the year, but are of particular importance during the winter. Indeed, lichens, which are high in sugar and thus energy, often form the bulk of the diet during winter. The diet may also include young grasses, birch shoots, flower buds and leaves during the spring and summer, and fungi during the autumn. Reindeer will also take shrubs, particularly cowberry and bilberry, and sedges according to availability, and can feed on plants that are toxic to other mammals, including wolf’s bane (Aconitum), hellebores (Veratrum) and broomrape (Pedicularis).

Although reindeer are primarily herbivorous, they will supplement their diet with animal protein if the opportunity presents itself. Reindeer have been observed scavenging fish and birds’ eggs as well as taking chicks from nests and even hunting lemmings in North America. They will also raid human rubbish dumps and actively lick human sweat and human and dog urine, presumably for the salt content. In fact, reindeer will lick salt off roads and drink brackish water, even seawater, the salt providing a noticeable enhancement of antler growth.

Reindeer cow with calfSex and sociability
Reindeer are gregarious by nature and will form herds of several thousand animals. A study published in the journal Arctic in June looked at the levels of aggression among reindeer and found that females were less aggressive, and thus more gregarious, than males; female-only groups were larger than either male-only or mixed-sex ones. The researchers also observed that females in mixed-sex groups were more aggressive than those in female-only ones, and this appears to be in response to the males being generally more aggressive.

Much of the herd dynamic comes about during the breeding season - the rut - when males actively round up females and try to monopolise access to them as they come into season. A bull’s herding expertise obviously has an effect on the herd composition. A study by Natasa Djakovic and colleagues looked at the kinship among reindeer cows during the rut in Finland, and found that females were more likely to hang out with related females - mums, sisters, aunts - when a mixture of male ages was present than when there were only mature or only young males around. It seems that mature, dominant bulls herd the females more efficiently and essentially control who they socialise with. With more young males around, the competition is greater and this distracts the mature bulls, allowing the cows greater freedom of association. A study by researchers at Canada’s Concordia University, published earlier this year, found very similar behaviour in their study herds – bulls actively herded cows during the rut, causing an increase in group size and stability. Low-ranking males, by contrast, had poorer body condition and were less efficient herders, so the females tended to associate with whomever they wanted when the younger males were in charge. So, it seems that, when females have the choice, they opt to socialise with family members, but during the rut they are often constrained by the control imposed by the dominant bull.

Reindeer rut during late September and October, and males will antler-clash with one another like other deer species when fighting for access to mates. The bulls attempt to keep the females together in a single herd so they can better protect them from interloping males. Interestingly, the Concordia researchers found that females may stay in the group for most of the breeding season but become choosier at the time of their estrus, at which point they call more and visit 'satellite' bulls outside the herd. Once successfully impregnated the female will gestate for about 7 months; if not mated, the cow will continue to cycle every 10-12 days until her oestrous cycle stops. Calves weighing 4.5-7 kg/10-15 lbs are born from May into the early summer. Typically only a single calf is born, although very occasionally a cow may produce twins. Tilly Smith of The Reindeer Company Ltd., which owns and manages the population of reindeer in the Cairngorms, tells me that in the herd’s sixty year history they have had only three instances of twins, the first in 1988 and subsequently in 2008 and 2010. Unfortunately, none of the twins survived the birth.

When the cow is ready to give birth, she will leave the main herd and seek isolation. The calf is born with significant deposits of fat - brown adipose tissue, to be precise - around the heart, kidneys, groin and shoulders, which allow it to thermoregulate – that is, maintain its body temperature – from birth. In most populations, the calf is up and following the mother within a couple of hours and the female returns to the main herd 20-30 hours after the birth. Woodland caribou, like most other deer species, hide their calves in vegetation. The calf feeds almost exclusively on mother’s milk for the first month or so then begins to take solid food. Reindeer milk is very rich, with the highest solid content (proteins, fats, minerals and carbohydrates) of any deer milk, enabling the calf to grow quickly. The calf will stay with its mother for its first winter, becoming independent by the following autumn.

Being large, typically Arctic mammals, reindeer have relatively few predators. Globally, and particularly in North America, their primary predator is the grey wolf, packs of which will take down adult and young deer. Brown bears and polar bears will occasionally also take deer of all ages, while wolverines take calves and very occasionally birthing or infirm individuals. Golden eagles will also take calves. Generally speaking, female reindeer tend to outlive males, and may survive for 17 years in good habitat, while males seldom exceed 14 years. The oldest of the Cairngorm herd was 19 years old and the oldest on record that I have been able to find was a female at Brookfield Zoo in Chicago which died in July 1978 aged 21 years and 8 months.

Antlers – biological bones of contention
Reindeer (Caribou) with one antlerAntlers are bony appendages that grow from specialised plates on the head called pedicles and, in most deer, are re-grown on a yearly cycle that is regulated by sex hormones. Antlers are the fastest growing mammalian tissue known to science, and complete regrowth of the antlers, which may be highly branched structures a metre/3ft long and weighing 20kg/44 lb. in some large cervids, completes in only a few months. More details on the growth, cleaning and casting of antlers can be found in my QA.

Most species of deer possess antlers, but it is ordinarily only the males that grow and subsequently employ them in fights with other males over access to females during the rut. Reindeer are unique in that both sexes routinely grow antlers. Interestingly, however, the presence of antlers in the females corresponds closely to the amount of snowfall, the snow depth and snow duration – the more snow the reindeer experience, the more females in the population grow antlers. Conversely, in habitats where winters are less harsh, like mountain forests, fewer female caribou grow antlers, and those that do often grow smaller or asymmetrical ones. Habitat notwithstanding, however, there is always a small percentage of wild females that doesn’t ever grow antlers. One study of 3,091 wild and captive reindeer cows in Alaska found that 152 (5%) of the wild population didn’t grow antlers, whereas all the captive females did. Male reindeer grow antlers regardless of the habitat.

Before we come to the 'why', let’s quickly explore how antlers are grown. Antler buds, which will develop into pedicles, are evident from about the age of three weeks in both male and female reindeer. Unlike other cervids, even castrated reindeer or those with their ovaries removed will grow, clean and cast their first antlers. Normally, castration prevents antler growth in deer. While the antlers are growing, they are covered by a delicate hairy skin that supplies blood. In September, when the antlers are fully grown, this skin dies and peels off in a process known as cleaning or shedding. Once cleaned, the antlers are ready to use during the rut. Mature males then cast their antlers during November and remain in an antlerless state during the winter until re-growth begins during February. Larger males cast and start re-growing their antlers earlier than young males. Non-pregnant females tend to cast their antlers around the same time as the immature males, in late winter or early spring, although some young males may retain their antlers until April. Pregnant females, by contrast, often hang on to their antlers until May, casting shortly after giving birth, which is why the presence of antlers in females during the calving season is often used as an indicator of pregnancy rates, although several studies suggest it’s not as clear cut as originally believed. One study of 517 female reindeer in North America accompanied by a calf found that about half the cows retained their antlers until shortly after their calves were born, while about one-third had lost one or both antlers on the day their calf was born, and just under 14% were already re-growing their antlers, suggesting that they’d cast at least two-weeks before the birth of their calf. So, the moral here is that there’s no hard-and-fast universally applicable rule as to when pregnant females cast their antlers. (Image: Antlers are rarely cast together. Typically one is cast and then there is a period of several days before the other is lost.)

The rapid growth of the antlers in late winter or early spring puts a substantial strain on deer at a time when they are nutritionally challenged. Lichens are high in sugar but low in protein and minerals, so when the antlers are cast they are eagerly licked and chewed by the deer to regain missing nutrients. Some deer will start chewing on each other’s antlers before they have been cast! Some biologists have suggested that casting antlers during the spring and summer provides a desperately needed source of minerals for the pregnant and lactating cows. During antler growth, minerals are sequestered from the deer’s bones, particularly the ribs, to supply the antlers. In other words, the deer undergo a period of temporary osteoporosis while growing their antlers, and this is only repaired as the antlers approach completion. Exactly what regulates the antler cycle in female reindeer is still unknown. Several studies have shown that the antler cycle in male deer is regulated by levels of testosterone and estradiol circulating in the blood. In females, however, the process is less clear. Early authors suggested that it was levels of circulating oestrogen that controlled antler growth, cleaning and casting in the cows because the drop in oestrogen caused by surgical removal of ovaries in non-pregnant females causes premature casting. Similarly, there is a fairly strong relationship between antler casting and parturition, and cleaning of antlers tends to occur close to the onset of ovarian activity, all inferring a hormonal influence. The suggestion was that barren females cast their antlers when their oestrous cycles stop and oestrogen levels drop, while the elevated oestrogen in pregnant females causes the antlers to be retained. A study published in 1997, however, found no correlation between antler mineralisation or casting in female reindeer and their levels of estradiol (an oestrogen), progesterone or testosterone. The mystery remains.

So, that’s the 'how', but why do female reindeer have antlers? Well, a clue is gained from our earlier observation that antler growth in females correlates positively with snowfall. Many reindeer cows are pregnant during the winter and therefore have higher energy requirements than the males and non-pregnant females in the herd. Much of their winter food is buried under snow and the reindeer dig small scrapes through the snow to get at the lichen. It is important that the cows are able to defend these feeding scrapes from other deer, thus securing as much energy as possible, and this is where the antlers come in. The pregnant females use their antlers to defend their feeding scrapes against others. This is very efficient against antlerless males, but less so against immature males and other females, both of which have antlers. Larger, dominant females may also pirate the feeding scrapes of subordinates, using their antlers to drive the current owner away. The use of the antlers only for defending feeding craters, and perhaps also for protecting their calves in the first few days of life (hence many not casting until after the calf is born) probably explains why females don’t grow the same elaborate and ornate antlers that males do – they simply don’t need them.  As long as the antlers can help the female secure food, that’s good enough. Perhaps more importantly, antlers are costly to grow and females divert a lot of energy and resources into laying down fat and producing their rich milk, so they don’t have much to spare on growing antlers. So, antler size tails off in females by the time they reach about three years old, while in males (which do need flashy antlers) they grow in size and complexity until about five years old. Males also continue to invest more in growing antlers as they get older, while females invest less.

Cairngorm ReindeerReindeer? In Britain? Seriously?
Yes! Various attempts have been made to introduce reindeer to Britain. Among the earliest was William Hamilton’s introduction of a pair on to the Beltrim Castle estate at County Tyrone in Northern Ireland in 1738. The Duke of Atholl released 14 deer on to his estate in the Scottish Highlands during 1790. Both of these attempts ended in failure, as did several subsequent releases by various landowners, despite the deer being released into apparently suitable upland habitat. On the 12th April 1952, however, things were set to change, as eight domesticated reindeer from Jokkmokk in Arctic Sweden flew into Glasgow airport, destined for an enclosure in the Cairngorms. This was represented the realisation of the vision of Lapland-born reindeerophile Michael Utsi and his wife Ethel Lindgren, who were convinced that reindeer were more useful, easier to train and tastier to eat than our native red deer, and that the Highlands of Scotland was an ideal habitat for them. Following a period of quarantine, the herd were released into a 3ha/300 acres enclosure near Loch Morlich on Glen More, Aviemore, on the lower slopes of the Cairngorms in May 1952.

The project hit several setbacks, including various ailments, one deer drowning in a loch, and the first reserve being at too low an altitude, which resulted in the herd being plagued by flies. In 1954 the herd, then numbering 17, was moved to a larger enclosure on the higher slopes of Airgold Meall (Silver Mount) where they thrived. By 1972 the herd had swelled to 80 deer and ranged over some 60ha/6,000 acres of the Cairngorms and, in 1990, a second herd was established at a site near Tomintoul. Several subsequent introductions of deer – from Sweden, Russia, southern Norway and the Zoological Society of London – have been made to improve the herd’s bloodline. During the winter the deer range over the mountains but they are brought down into pastoral enclosures to give birth, which helps protect the calving cows and their calves from walkers’ dogs and from eating litter, which are two of the most significant threat to these deer in the Cairngorms.

Utsi died in 1979 and his wife passed away in 1988. Shortly after, in August 1989, the herd was taken over by Alan and Elizabeth Smith and the deer were no longer culled for meat or fur, instead being used mainly as a tourist attraction and to appear at Christmas events across the country. Today, the Cairngorm population is closely managed by The Reindeer Company Ltd., who maintain the herd at 130-150 animals.

In conclusion...
There are so many fascinating aspects to the biology and behaviour of reindeer that I could fill volumes. Indeed, this article is already longer than I had planned, although I hope you found it interesting. Without protracting this any further, I will leave you with three 'bet you never knew' facts about reindeer with which to amaze your family over the festive season.

Whatever you’re up to during this time, take care and I look forward to seeing you back in January. Thank you for your interest and support during the past year and a very Merry Christmas and Happy New Year to you and your family. As always, I love hearing from readers; any queries or comments regarding the information on the site can be sent in using the addresses on the Contact page (Note: Some website questions are answered on the FAQ, while many animal-related questions are covered in the Q/A). Photos can be e-mailed to a dedicated e-mail address - please keep them coming and don't forget to check out my Photos Needed page. I'm also interested in hearing any reports of unusual behaviour in any of the animals featured on this site, or interactions between humans and wildlife. My sincere thanks are extended to Steph Powley and Ali Magnum for their proof-reading services this month, to Tilly Smith of The Reindeer Company for providing information on the Cairngorm herd, and to Laura Philip and Ken McInnes for letting me use their excellent photos of the cairngorm reindeer.

Did you know?

Reindeer (Caribou) herd1. Reindeer can see ultraviolet light and may use it both to locate plants in the snow and avoid overhead power lines, which give off a corona of irregular flashes of UV (200-400nm). Nick Tyler at the University of Tromoso in Norway and colleagues also found that plants absorb UV while snow reflects it, making plants show up to the reindeer as dark shapes on a bright background and helping them find food in the depths of winter.

2. Reindeer make a clicking noise when they walk. The noise is caused when tendons in the legs rub over bony protuberances called sesamoid bones in the ankle. This clicking can be heard up to 40m/131 ft away on a still day and is believed to help keep the herd together in conditions of poor visibility. Reindeer living in the Arctic undergo seasonal changes in eye colour, from golden in the summer to blue in the winter. At the back of the eye is a layer of reflective cells called the tapetum that reflects light back into the eye, enhancing vision in poor light and giving the eyeshine so familiar in other mammals. The golden colour is a result of most wavelengths of light being reflected by the tapetum. During Arctic winters the reindeer’s pupils dilate in response to the darkness and may stay dilated for months. This prevents fluid draining from the eye, causing it to swell and press against the tapetum. The resulting distortion of the tapetum reduces the gap in the collagen layer at the back of the eye and causes shorter wavelengths of light to be scattered most readily, hence the blue colour. Some scientists have suggested that this blue colour may help enhance the reindeer’s vision in low light, helping it to spot food and predators more easily.


WildlifeonlineOkay, for those of you that are new to the site, let's take it from the top!

What is Wildlife Online?
Essentially, WLOL is an educational website about British wildlife. The site contains profiles of various British animal species, with new articles in preparation all the time. The site also has articles looking at wildlife-related subjects, including hunting and animal emotions. This site is purely a hobby of mine; it does not generate any money or contain any advertising and, for the time being at least, I am happy for it to stay that way.

What does Wildlife Online aim to achieve?
The ultimate goal of the website is to be useful. My intention has always been to provide un-biased, accurate information that’s accessible to anyone with an Internet connection. Increasingly people are coming into contact with their local wildlife and whether such interactions are positive or negative, they generally inspire a desire to learn more about the species. Moreover, there are still a great many misconceptions surrounding our wildlife (fox behaviour springs immediately to mind) and these are brought up time and time again during discussions in the media. Each article aims to provide a reasonably comprehensive overview of the species in question by drawing on information from the media, books, TV programmes and the scientific literature. I feel that this combination of sources, along with my own observations and those of my friends/colleagues/readers provides a unique online resource of British wildlife information. My hope is that the information provided here will go some way to changing people's perceptions of the creatures with which they share their parks and gardens.

Why create a website when there are books and TV programmes about your subjects?
Books can be a fantastic resource and I can't imagine being without my library. Not all libraries, however, are equally well stocked, and not everyone has the funds to splash out on what are often very expensive wildlife books (especially those written by scientists). More importantly, much of the scientific research never makes it out of the journals into books and TV shows. Similarly, many of the early books -- which contain some of the pioneering work on the species -- are now long out of print and can be difficult or expensive to track down. Books have the 'luxury' of being able to devote their entire contents to a particular species, covering all aspects of its life history. Television, by contrast, is a much more limited and variable medium: the programme editor(s) has to create a show that is likely to hold the viewers' attention and appeal to a very wide audience. The result is that, although some reach this compromise very well (the BBC, for example), many documentaries focus heavily on the 'wow factor' (multitudinous slow motion shots of Great whites leaping out of the water in pursuit of seals, for example) and this often comes at the inevitable expense of the information about the animal. Finally, both books and TV programmes go out of date quite quickly; new research is being conducted all the time. Consequently, a website is an ideal and dynamic intermediate - it offers the opportunity to provide a decent amount of information about the subject that can be updated at the metaphorical drop-of-a-hat as any new research is published.

Why include so much information?
I honestly believe that if a job is worth doing, it's worth doing well. There are hundreds of websites with brief species profiles and if that's all WLOL offered there would be little point to it. I understand and appreciate that some people find being confronted with large volumes of text very daunting while others are of the 'too long; didn't read' mind-set and will thus be turned off by the amount of text facing them. I have tried to remedy this as far as possible via two avenues: there is a Speed Read section with a brief profile of each species featured in a main article; and each article has been 'virtually split', with the aid of hyperlinks, into sections that allow people to easily jump to the information they're looking for. Ultimately, I want to provide as much information as is feasible in order to provide the reader with the clearest appraisal of each species or topic; I hope that most readers approve of this approach.

Why haven't you included a complete bibliography?
My intention with WLOL is to provide the information in an accessible format, which means that anyone should be able to read an article and understand the information in it. Consequently, I didn't want to format it as a scientific paper because the current format allows for a much more informal approach and writing style which, I hope, will appeal to a wider audience. Most people should find enough information in the article (I typically provide the name or one or more of the authors and the journal and year) to track down the original scientific paper. When I take information from books, I always give the name of the author(s) and the full title of the book for easy reference. I am also happy to provide full details of any of the references upon request.

Are you really qualified to do this?
I'm certainly not an expert on any of the subjects presented on this site. The articles stem from my varied interests in natural history and biological sciences. In terms of qualifications, I trained as a scientist (studying natural sciences at degree and postgraduate level) and all I really do is interpret information, blend it with associated research and personal observation, and present it in what I hope is an accessible format. Unless specifically stated, I do not claim any of the information on this site to be my own research. I have built relationships with some of the many diligent researchers who have produced the data that I use, and I am happy either to recommend an expert or provide my own opinions on a subject.

As a final note, I want to make a quick reference to the quality of the material on the site. The great French philosopher and mathematician, Rene Descartes, once said: "If you would be a real seeker of truth, you first must be willing to doubt as far as possible all things." This is very sage advice, especially when it comes to believing what you read on the Internet. Most Internet sites (indeed, some books and TV shows too), including this one, have no form of peer-review (i.e. nobody with experience of the topic checks the site for accuracy); consequently pretty much anyone can have their own little corner of cyberspace and information can make it onto websites that is either misguided, or downright false! When creating material for this site I take every care to ensure that the information I present is accurate. Invariably errors will creep in; typos are almost inevitable (although each article goes through several levels of proof reading before it appears online) and research is always underway on the species featured here, so the data can go out of date almost overnight. Each page has regular (ish!) reviews, however, during which I update the information, adding details of new findings and taking out that which is now thought highly unlikely. You can see most of the books I have used in the preparation of this site on the Recommended Reading page and I have provided links to some of the most interesting sites I came across during my research – these can be found under the appropriate sub-heading on the Links page.

Anyway, I digress.... I hope you enjoy looking around the site and I hope equally that you get something worthwhile out of it. Any comments, suggestions or (constructive) criticisms are welcome via e-mail - appropriate addresses can be found on the Contact page.


DISCLAIMER: All the photographs and artwork on this site are either my own work or have been donated by readers. All images remain property of their authors and, if you wish to reproduce any of the pictures, consent must be granted by the appropriate person - requests can be directed via myself or see FAQ. For more details on the content of this site, please see the full WLOL Disclaimer.

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