Species of the day: Roe Deer
By James Duncan
Learning and Engagement Officer
The elegant Roe Deer (Capreolus capreolus) is one of six wild deer species that reside in Great Britain. Of these, only two are truly native, the lightweight Roe being one, the significantly heftier Red Deer the other. Technically, today's British population of around half a million descend largely from deliberate reintroductions from mainland Europe in Victorian times. This might seem rather odd considering their native status, but the Roe Deer has suffered catastrophic persecution at the hands of man. In combination with extreme levels of historical deforestation, they'd been almost entirely exterminated from our lands by the Eighteenth Century. Nowadays their range is extensive and they're probably the most abundant member of their family (Cervidae), though in contrast are entirely absent from Ireland. The Roe Deer belongs to an Order of animals known as Artiodactyla, the even-toed Ungulates, hoofed animals where weight is evenly distributed on two of their five toes, giving them a cloven-hoofed footprint.
As a whole, the Roe Deer is a shy, retiring species and as with many of our mammals, likely to spend more time observing you than the other way round. Largely a woodland inhabitant, they favour refuge habitats though will forage around field edges and farmland providing cover is nearby. They're predominantly crepuscular (active mainly at dawn and dusk) though can be relatively easy to observe (from a distance) in their favoured areas. Typically rather solitary they can sometimes be seen in small family units, though it's usually only in winter that larger aggregations occur. They often seem to appear when least expected and perhaps the most common sighting is that of an individual bounding away on spring-loaded legs, the diagnostic white rump fluffed out like a giant powder-puff. This is known as 'stotting' or 'pronging', a method of locomotion more familiar amongst antelopes of the African savannah. The seriously sprightly Roe Deer may easily clear ten metres in a single bound at speeds regularly in excess of thirty miles per hour.
Roe Deer - doe and buck © Darin Smith
With a suite of super senses, the Roe Deer is able to minimise risk whilst foraging - superb hearing and a highly developed sense of smell (olfactory system) ensure it can remain vigilant at all times. Like many vertebrates their eyes are well adapted for low-light living, owing to a layer of reflective tissue known as a tapetum lucidum, which increases the amount of available light entering the eye. At night, this manifests itself to us as reflected eyeshine, though serves to give the deer superior night-vision, an essential for any prey species. When agitated, a Roe Deer may well stamp a foot or even utter a surprisingly dog-like hoarse bark. This vocalisation is also used by males (bucks) to aggressively challenge rivals during the rut. Their rut occurs earlier than most other deer, from mid July, though bucks will already have established territories in May through copious scent-marking. Their antlers are shed in late autumn (as opposed to spring), another characteristic differentiating them from their relatives. Antlers are the fastest growing bones in the animal kingdom, re-growing immediately upon shedding in the Roe Deer's case and fully formed by March.
When a buck detects a fertile female (doe) the chase may quite literally be on. It might be a good few days until a doe is ready to mate and during this time a 'roe ring' may form - this is a severely trampled track created as the buck sniffs and chases the doe. In an unusual departure amongst ungulates, a fertilised egg won't develop until winter, a reproductive strategy known as delayed implantation. This has the major benefit of ensuring young aren't born until late spring, saving them from perilous winter conditions. Since their remarkable recent recovery, the Roe Deer is now somewhat seen as both a positive and negative influence in the countryside. Quite simply, following the eradication of Wolves, Lynx and Bears, they have no natural predators and their browsing habits heavily impact the environment. Their boom in numbers leads to overgrazing in young woodland, preventing regeneration and a diversity of structure, something that proves devastating for a wealth of other woodland species.
Roe Deer - buck © Elliott Neep