Roe deer

Name and taxonomy

The English word roe comes from Old English and is related to the German Reh and the Dutch ree. It may trace back to an old root that meant streaked or spotted, a fitting name for a spotted fawn. The word appears in runes on a 5th-century deer ankle bone found at Caistor-by-Norwich. For centuries the animal was simply the roe, and roe deer is a later habit. The Latin Capreolus is a diminutive of capra, a goat, and may once have meant an ibex or a chamois.

Linnaeus named the species Cervus capreolus in 1758. John Edward Gray proposed the genus Capreolus in 1821, but most writers ignored it until the 20th century. The type locality is Sweden. Some lists give subspecies in Spain, Italy and the north Caucasus, but two leading specialists treated the species as having none in 2001. The Siberian roe deer of Russia and East Asia was split off as its own species from 1985, based on protein and chromosome studies. Mammal Species of the World adopted that split in 1993.

Evolution and relatives

The roe deer belongs to the Capreolinae, the subfamily that also holds the deer of the Americas. Its closest relative is the water deer, and the pair sit nearest to the moose and the reindeer. The genus probably descends from Procapreolus, a Eurasian line of about 10 species that spread west from the Late Miocene onward. The European and Siberian species parted between 1.375 and 2.75 million years ago. The western species first appears in Europe about 600 thousand years ago.

During the last ice age the roe deer retreated to refuges in Iberia, southern France, Italy, the Balkans and the Carpathians. It moved north to Germany about 12.5 thousand years ago and vanished again in the cold Younger Dryas. It came back for good about 9.7 thousand years ago. Genetic data suggest that the modern northern population came from the Carpathians or further east, the opposite of the red deer's route from Iberia. Since the 1960s the European and Siberian species have met again, and a broad hybrid zone runs from the Volga to eastern Poland. Female hybrids are fertile, male hybrids are not, and the young grow so large that some births needed a Caesarean section.

Appearance

The roe deer is a small, elegant deer with a long neck, a short body and a rump that sits higher than the shoulders. The summer coat is red-brown, and the winter coat is grey-brown to dark brown and much thicker. The deer moults in April to June and again in September to October. The muzzle is black, the chin and lips are white, and the ears are large, about 12 to 14 cm. In winter a big white rump patch shows: kidney-shaped on a buck, heart-shaped on a doe. The doe has a tuft of white hair under the rump that looks like a tail. The true tail is only 2 to 3 cm.

Body length is 95 to 135 cm and shoulder height 63 to 67 cm. Bucks weigh 22 to 30 kg after the rut, and they run 5 to 10 percent heavier than does. The heaviest animals live in Scandinavia and the Baltic states, and the lightest in Spain, Italy and cold alpine valleys. Antlers are short, about 16 to 23 cm on an adult buck, with three points and a rough, pearled base. Good bucks reach 20 to 25 cm, and a four-point head is rare. Bucks cast their antlers in October or November and, unlike most deer, start to regrow them at once.

The new antlers grow under velvet, which the buck rubs off on saplings in March or April. Fawns are brown flecked with black, with white spots along the sides and back that fade by about five months. The hooves are narrow and pointed, 4 to 5 cm long. There are no glands in front of the eyes, but a buck has a scent gland on the forehead between the antler bases.

Habitat and range

The roe deer lives across almost all of mainland Europe. It is absent from Iceland, Ireland, the far north of Scandinavia and the Mediterranean islands. Eastward it reaches western Russia, Ukraine, Turkey, the Caucasus, northwest Syria, northern Iraq and northern Iran. It is extinct in Lebanon and Israel, though Israel began a reintroduction in the Carmel hills in the 1990s. Scottish deer released in County Sligo in about 1870 survived for some 50 years and then died out.

The deer needs food and cover, and beyond that it is not fussy. It lives in Mediterranean scrub, boreal forest, Scottish moorland, alpine slopes up to 2,400 metres and open farmland. In the southern Czech Republic it lives in almost treeless cropland. By day it rests in dense wood, conifer plantations or bramble, though a hedgerow will do. Deep snow sets the northern limit, because the deer struggles in more than 40 cm.

It is a pioneer of young woodland and forest edge, and it spread when Neolithic farmers first cleared the forest. In Britain it was almost gone from the south in 1900, but it has since retaken most of England and reached Wales. German deer released in Thetford Forest in 1884 stocked much of East Anglia. Roe deer now live in cities such as Glasgow and Bristol, where they like cemeteries. In Flanders the spread of tall maize crops, which give cover, may have helped the deer move west.

Diet and feeding

The roe deer is a browser and a selective feeder. It picks soft food rich in sugars, protein and water: buds, shoots, leaves, forbs, berries and, in autumn, seeds and fruit. It likes tender young grass, best of all after rain. Across Europe it eats about 1,000 plant species, and up to 370 in one region. One analysis put the diet at 54 percent broadleaved herbs, 25 percent woody plants and 16 percent grasses and sedges. Conifer needles are winter food only, taken when little else is left.

The rumen is small, so the deer feeds often, about 9 to 11 times a day, with the longest bouts at dawn and dusk. Daily intake is about 2 to 4 kilograms of fresh plants. It carries little body fat, so it must find most of its energy in food even in winter. Large salivary glands let it cope with tannins that would poison many other herbivores. Roe deer usually avoid fields where livestock have grazed. In Iran it eats many seeds but spreads few of them, so it is a poor seed disperser.

Behaviour and social life

Roe deer are not very social. In summer they live alone or as a doe with her fawns. From September to February does form small groups of 2 to 4 with their young and sometimes a buck. Two families may join into a clan of 6 to 8, and on open farmland loose herds of 40 to 90 gather in snowy winters. These spring gatherings break up as soon as the bucks turn aggressive and move to their territories.

From April to August an adult buck holds a territory and drives other bucks out of it. He marks it by rubbing saplings with his forehead, fraying plants with his antlers and scraping the ground with his hooves. One study counted about 90 scrapes and about 95 rubs per hectare. A buck can hold his ground for 5 to 7 years, and each year an old holder faces a young challenger. Yearlings live in the gaps between territories or attach themselves to a tolerant older buck.

The deer stays in cover by day and moves into the open at dusk, at night and at dawn. It scrapes the leaf litter aside to make a bed. Home ranges average 5 to 7 square kilometres in woodland and 8 to 10 in open country. In the Alps and Scandinavia some deer move 4 to 12 km down to the valleys for winter. It can jump about 5 metres in length and clear a high fence.

Communication and senses

The alarm call is a bark much like a dog's, given as the deer flashes its white rump and bounds away. Bucks also bark and give a low grunt. During the rut a doe gives a high, thin whine to draw a buck. Fawns, does and bucks of the European and Siberian species each make different sounds.

Scent matters more than sound. A buck's forehead gland, hoof glands and leg glands leave marks on saplings, scrapes and trails. He follows the scent trail of a doe and tests her state with the vomeronasal organ in the roof of his mouth. Like other deer, the roe probably relies on large ears and a keen nose more than on sharp eyesight. The white rump patch is thought to be a visual signal that warns the group and confuses a pursuer.

Reproduction and life cycle

The rut runs from mid-July to mid-August. A doe is receptive for only 36 to 48 hours in the whole year. The buck chases her first in wide circles and then in tight circles or figures of eight. The trampled plants form roe rings 1 to 3 metres across. He stays with her for 2 to 4 days and then seeks another doe. A buck may lose about 10 percent of his weight during the rut. Does often go looking for a buck themselves and lead him back to their own range. A buck may mount the same doe many times over several hours.

The fertilised egg travels to the uterus but does not implant. It rests as a tiny blastocyst for about five months and implants in January. The roe deer is the only hoofed animal with this delay, and the trigger is the embryo itself, not day length. True growth then takes about 150 days, so the whole pregnancy lasts about 10 months. Fawns arrive in May or June, and twins are the rule in most of Europe. Heavy Scandinavian does often bear triplets, and Mediterranean does often bear one.

A newborn weighs about 1.3 kg, and it doubles that within 10 to 15 days. For the first weeks it lies hidden in long grass and freezes at danger while its mother feeds 50 to 150 metres away. She suckles it 5 to 9 times a day in the first month, and lactation lasts about three months. Does breed from about 14 months, but bucks rarely win a mate before 2 to 3 years. A normal wild life is 7 to 10 years, and the record is about 20. In hunted populations the average deer lives under three years.

Predators and threats

The gray wolf and the Eurasian lynx are the main predators. The red fox takes young fawns, and in the Alborz Mountains of Iran the Persian leopard depends on roe deer. Feral dogs kill deer in southern Italy and Spain. Britain has no large predators left, which is one reason its roe deer have spread so far.

Most deaths come in the first weeks, from predators or from farm machinery cutting hay over hidden fawns. The first winter is the next hurdle, and in a bad year up to 90 percent of fawns die of hunger or disease. Road traffic kills many deer, and in some countries the numbers are high enough to be a safety problem. Poaching, competition with livestock and crossing with released stock threaten some Mediterranean populations. A gut nematode, Spiculopteragia asymmetrica, infects the species.

Population and conservation

The IUCN lists the roe deer as Least Concern. Europe holds about nine million, of which 2 to 9 million are shot each year. Densities run at 5 to 25 deer per square kilometre, and up to 50 to 70 in the best places. The species can double its numbers in a year, because does keep breeding even when the population is dense. Hunting in the 17th to early 20th centuries pushed it back across most of Europe. Better laws, new forests and reintroductions then let it retake its old range.

The Netherlands had almost none in 1875 and about 110,000 in 2016. Israel imported 27 deer from France, Hungary and Italy in 1991 and released the first into the Carmel hills in 1996. Ireland has had a few unconfirmed sightings, and one confirmed in County Armagh in 2014. In some countries the population is now too large for the woods, and game managers cull it.

Relationship with humans

The roe deer is the most valuable game animal in Europe. In 1998 hunters shot about 2,500,000 in western Europe, and Germany alone took 700,000 a year in the 1990s. Even that harvest has not slowed its growth. Most venison eaten in Europe comes from this species, and the meat is darker than that of farmed deer. In the Middle Ages ordinary people could hunt it, unlike the red deer of the nobles.

Deer browsing damages young trees, and dense herds change the plants of a woodland. Collisions with cars are the main harm the deer does to people. The deer is shy and harmless to people, though a cornered buck may gore a dog. Its abundance makes it one of the most studied wild mammals in Europe.

In culture and myth

Deuteronomy lists the yahmur among the animals that may be eaten, and most Bibles render the word as roe deer. The King James Bible chose fallow deer instead. Older Bible translations also applied the Greek pygargos to the roe, though scholars now think it meant the addax. In ancient China an albino roe was so rare that it was treated as a sacred animal or a national treasure. In the Grimm story of the brother and the sister, the boy drinks from a cursed stream and turns into a roe deer.

Bambi was a roe deer in the Austrian book, and Disney changed him into a white-tailed deer for the film. Medieval bestiaries used deer as emblems of timidity and speed. Hunters in Central Europe once spared any white deer, which they read as an omen. Spirit-animal websites read the roe as gentleness and sensitivity, but those claims are modern and probably owe more to Bambi than to folklore.