Capreolus capreolus, Gray, 1821

Don E. Wilson & Russell A. Mittermeier, 2011, Cervidae, Handbook of the Mammals of the World – Volume 2 Hoofed Mammals, Barcelona: Lynx Edicions, pp. 350-443 : 427-428

32.

Western Roe Deer

Capreolus capreolus

French: Chevreuil d'Europe / German: Reh / Spanish: Corzo

Other common names: European Roe Deer

Taxonomy. Cervus capreolus Linnaeus, 1758 ,

Sweden.

The Western Roe Deeris recorded in Europe from the Middle Pleistocene, about 600,000 years ago. It was present on most of the continent during Interglacial and mild stages of glacial periods. During the last glacial maximum, 21-15,000 years ago, roe deer retreated to a few ice-free refugia in the Mediterranean region and in South-eastern Europe. About 9600 years ago, the deer began to recolonize Western, Central, and Northern Europe, possibly from one eastern glacial refugium. Due to substantial morphological homogeneity, most recent authorities consider the species as monotypic.

Distribution. Most of Europe (excluding Iceland, Ireland, and Mediterranean Is), Caucasus, and Near East.

Descriptive notes. Head-body 107-127 cm,tail 1.5-3 cm, shoulder height 65-84 cm; postrutting weight 20-30 kg for males (adult bucks) and 17-29 kg for females (adult does). Bucks are on average 5-10% heavier than does. The heaviest animals are found in Scandinavia and the Baltic countries, the smallest in Mediterranean habitats of Spain and Italy and in cold alpine valleys. It is an elegant small deer with long neck, relatively short trunk, and rump higher than withers. The area around the muzzle is black, the lips and chin are white. The winter coat is grayish. Bucks have a large, white, kidney-shaped rump patch; in does the rump patch is heart-shaped and there is a prominent tuft of hairs close to the vulva. The summer coatis reddish, without a clear rump patch. The faces of bucks have a variable admixture of colors, from dark brown to grayish, sometimes with a whitish area toward the muzzle. The molt to summer coat occurs in April-June, and to winter coat in September—October. Newborn fawns have a brown coat flecked with black and with white spots on sides and back; the spots start to fade at six weeks and disappear by about five months. Preorbital glands are absent; metatarsal glands are brown and distinct; interdigital glands are well developed. An important glandular area, called the “frontal organ” by the first describers, is present on the forehead and between the pedicles of bucks. In late spring and summer, these sudoriferous glands produce a secrection used to mark territories. Western Roe Deer have a permanent dentition of 32 teeth; the teeth erupt at 3-13 months of age. Antlers are short (16-23 cm on average in adult bucks) and light, typically three-pointed, rugged by pearling in the lower half and with a well-developed burr. The basal anterior point (brow tine) is absent, replaced by a central one. Pedicles are close and the pair of antlers is often lyre-shaped. Pedicles grow precociously at about four months. Fawns normally develop their first rudimentary antler set (bony buttons or tiny spikes 1-2 cm long) at 6-7 months. These are retained for about two months. A second set of antlers begins to grow immediately, and is clean of velvet by May-June; yearling antlers are often spikes 10-14 cm long, but can be also have twoor three-pointed beams. Fawn males that weigh less than 14 kg by theirfirst winter do not develop antlers. Their first set, generally 3-5 cm spikes, appears the following spring. At 3-6 years antlers attain their full size. Regression begins by eight years. In adult bucks velvet shedding occurs in March-April, antler casting in October-November. Hooves are 4-5 cm long, narrow, pointed, with toe pads extending right out to the tips.

Habitat. The body structure, with the hindquarters higher than the shoulders, makes Western Roe Deer particularly adapted to moving in thick vegetation. Originally it was associated with early successional stages of the forest, young tracts of woods and scrubland. During the Neolithic Revolution, when a transition occurred from huntinggathering to agriculture and settlements, progressive forest fragmentation and the creation of wood clearings, meadows, and cultivated areas, gave Western Roe Deer new opportunities. The higher proportion of forest edge in the mosaic landscapes typical of traditional agriculture was particularly suitable to the species. Today Western Roe Deer occur in a wide variety of habitats, from the maquis scrub of the Mediterranean coast to the boreal forests of Scandinavia, and from Scottish moorlands to modern farmland with scarce cover. They live in the Alps up to 2400 m. Northern and north-eastern range limits seem to be largely determined by snow depth. The heavy foot loading and the low chest height makeit difficult to move in snow more than 40 cm deep.

Food and Feeding. Western Roe Deer are typical selective feeders or concentrate selectors, preferring soft food rich in soluble carbohydrates, proteins, and water. They have a relatively small rumen (4-6 1) and abomasum, and large salivary glands and liver; they are able to detoxify secondary plant metabolites. They are opportunistic and flexible deer, consuming up to 370 plant species at the regional level and about 1000 at the continental scale. Buds, shoots, and leaves of shrubs and deciduous trees, and green leaves and flowers of forbs (dicotyledon herbs) are particularly important; seeds and fruits are also eaten, especially in autumn. It seems that roe deer have physiological mechanisms that allow soluble carbohydrates to avoid microbial fermentation in the rumen and to be directly absorbed in the small intestine. With the onset of vegetation growth in spring, metabolic rate and food intake increase, reaching a peak during early lactation and the rutting period in summer; in winter basal metabolism and appetite decline. Daily food intake is 2—4 kg of fresh vegetation. Since roe deer have very scarce body reserves of fat, they need to obtain most nutrients directly from their food. This requires a greater tolerance for food of low nutritional quality, especially in winter, which is unusual for a browser. Special adaptations of the salivary glands make roe deer, unlike most herbivores, insensitive to toxic effects of high concentrations of tannins.

Breeding. Females attain puberty at 14 months of age and normally begin to reproduce immediately. Males reach physiological maturity at the same age but generally begin to participate in reproduction only at 2-3 years of age. Mature spermatozoa are present from March to October, but the rutting season is restricted to mid-July-mid-August. Females are monestrous, becoming receptive only for 36-48 hours during mid-summer, without the possibility of being fertilized a second time. Adult bucks follow olfactory traces of does, evaluate their status using the vomeronasal organ, and, having spotted a receptive doe, begin a courtship pursuit. This consists initially of a long chase in large circles, then in close runs in small circles or figure eights. Bucks remain with a doe for 2—4 days, and then move to find other estrous does residing in the neighborhood. During rut bucks lose about 10% of their weight. Females can take an active role in mate selection by making excursions out of their home range,visiting a territory holder, and mating with him. Fertilization is followed by a five-month period of “embryonic diapause.” The fertilized ovum penetrates into the uterus without implanting in the endometrium, reaching a blastocyst stage 0-1 mm in diameter, resulting in a blastula 5 mm in diameter. Implantation of the embryo occurs in January. The true gestation period lasts about 150 days, with the birth season in May-June. Does give birth to 1-3 fawns; in most of Europe two is the rule, but in Scandinavia, where mothers are particularly heavy, triplets are common, and in Mediterranean habitats frequently only one fawn is produced. Newborn fawns weigh on average 1.3-1. 9 kg, doubling their mass by 10-15 days. During the first weeks they remain hidden and in case of danger they “freeze”; their mother eats and rests about 50-150 m away. They are fed 5-9 times a day during the first month, 2-4 times during the second, and 1-2 times during the third month. Lactation lasts about three months. They begin to ingest their first leaves at about ten days and feed completely on vegetation by early September. At one month they are active for 1-1-5 hours per day. At weaning they synchronize the rhythms of activity with those of their mother. At 7-8 months males begin to be slightly heavier than females. At 3—4 years, roe deer attain full adult size. At eight years they enter senescence. Normally they live to a maximum of 10-12 years, with records of 14 years for bucks and 18 years for does. In populations subjected to hunting, averagelife expectancy is less than three years. Gray Wolves (Canis lupus) and Eurasian Lynxes (Lynx lynx) are the main predators; foxes may prey on young fawns.

Activity patterns. The small size of the stomach requires the deer to feed frequently, generally 9-11 times during a 24hour day. Roe deer are active all day, alternating periods of foraging, ruminating, resting, and moving. Feeding bouts at dawn and dusk have the longest duration.

Movements, Home range and Social organization. Western Roe Deer are cursorial and saltatorial, able to jump up to 5 m in length and 2-5 m in height. The deer are typically sedentary, with home ranges averaging 5-7 km? in wooded habitats and 8-10 km? in open habitats. Adult bucks from 2-3 years of age are territorial between April and August. When population density is low, defended territories are strictly exclusive. At high density they show some overlap, with each buck preserving a core area. Territories are defended and patrolled by means of self-advertisement, threat displays, and, more rarely, overt fights. Bucks mark by using olfactory and opticalsignals,i.e. rubbing saplings with forehead, fraying plants with antlers, and scraping ground with hooves. There can be about 90 scrapes per hectare and about 95 rubs and frayings per hectare. A buck can retain his territory for 5-7 years. When aged bucks lose their territory, they restrict their movements to a small area or become nomadic. Yearling bucks and sometimes two-year-old subadults are non-territorial and relatively mobile; some of them, known as “peripherals,” occupy a small range within the buffer zone between the territories of two adults, and others, known as “satellites,” associate with a territorial buck who tolerates a subordinate. In Scandinavia and the Alps, in areas where a snow depth gradient exists, part of the population tends to move to valley bottoms in late autumn and remain until spring, making small 4-12 km migrations. Western Roe Deer are not very social, living alone or in small groups. Bucks are solitary during the territorial period (late spring and summer), does in the last part of their pregnancy and at parturition time. From September to February adult does tend to form small groups of 2—4 animals, with their offspring, and occasionally with an adult buck. Two family units can form matrilinear clans of 6-8 animals, sometimes coalescing in larger fluid aggregations, especially in open habitats (meadows, farmland). Larger groups are particularly common in snowy winters and at the onset of spring, with the first green vegetation. Early spring aggregations are temporary and fragile, since adult bucks begin to be aggressive, to determine their rank order, to displace yearlings, and then to move to their territory.

Status and Conservation. Classified as Least Concern on The IUCN Red List. Presently the Western Roe Deer is the most common deer species in Europe, numbering about nine million head, of which 2-9 million are annually harvested. Densities are normally 5—=25 ind/km?, with maximums of 50-70 ind/km?. In the Near East it is extinct in Lebanon and Israel (where a reintroduction program was begun in 1997). During Mesolithic times in Europe it was probably less abundant than the Western Red Deer ( Cervus elaphus ), confined to thick woods, glades, and clearings. But habitat changes caused by humans give it new opportunities. During the Medieval and Renaissance periods, roe deer hunting generally was not restricted to nobles or reigning houses. Overhunting was responsible for a significant decline in the species across most of Europe between the 17" century and the first half of the 20" century. The reinforcement of laws, the recovery of natural habitats, and reintroductions, coupled with the extreme ecological flexibility of the Western Roe Deer and its high reproductive potential, made possible a recolonization of vast areas and an increase in density. Populations in Mediterranean regions such as southern Italy and Spain are still threatened by poaching, feral dog predation, competition with livestock, and genetic pollution.

Bibliography. Andersen et al. (1998), Apollonio et al. (2010), Danilkin & Hewison (1996), Melis et al. (2009), San José & Lovari (1998), Sempéré et al. (1996), Sommer et al. (2009), Stubbe (1990).

Figures

On followmg pages 30 Barasıngha (Huoervus duvıuoelıı) 31 Chınose Water Deer (Hydroporos ınermısl 32 Western Roe Deer (Capreolus aıpmolus), 33 Eastern Roe Deer (Capraolus pyyaryus)

Distribution. Most of Europe (excluding Iceland , Ireland , and Mediterranean Is), Caucasus, and Near East.