Red deer

Red deer eat grass and small plants.

They also eat heather and berries. In winter, when food is hard to find, they nibble tree shoots.

Red deer mainly eat grasses, plus sedges, rushes, herbs and small shrubs such as heather and bilberry. In winter, when other food is scarce, they browse on woody plants like tree shoots.

That can cause problems. Deer that eat young tree shoots and farm crops can damage forests and fields, which brings them into conflict with farmers and foresters.

Red deer graze grasses and dwarf shrubs such as heather and bilberry, and take sedges, rushes and herbs; woody browse, including tree shoots, becomes important when food is limited in winter. Deer in woodland grow larger than those on open hills because their food is of higher quality.

Browsing of tree shoots and crops brings red deer into conflict with farmers and foresters. The Woodland Trust notes that with no large carnivores left in the UK, deer densities can become very high, and overgrazing can prevent woodland from regenerating, with knock-on effects for other forest plants and animals.

In autumn, stags roar very loudly.

They show off to the hinds. Sometimes two stags push with their antlers. The strongest stag wins.

Outside the breeding season, stags and hinds live apart. On open hills, hinds and their young gather in big herds, while stags live in loose groups. In woodland, red deer live in smaller groups, often just a mother and her calf.

From late September to November comes the rut. Stags roar, walk side by side to size each other up, and sometimes lock antlers and push. The winning stag stays with a group of hinds. Red deer are most active at dawn and dusk.

Red deer society depends on habitat. In woodland they are largely solitary or in mother-and-calf groups; on open ground they form larger single-sex groups, which in the Scottish Highlands may persist for most of the year. They are active around the clock with peaks at dawn and dusk, and disturbed populations use open ground more at night.

During the rut, from the end of September to November, stags assess each other through roaring and parallel walks; fights, which can cause serious injury, occur mainly between stags of similar size that cannot settle dominance otherwise. The dominant stag then mates with the hinds. In the UK adults have no natural predators, though foxes and golden eagles may take young.

There are lots of red deer.

In some places there are so many that they eat all the young trees. People manage the deer to keep forests healthy.

The red deer is not endangered: the IUCN lists it as Least Concern, and its numbers are growing. In Britain, hunting and the loss of forests made red deer rare by the late 1700s, but they have spread again over the last hundred years.

Now, in Britain, where no large predators are left, there can be too many deer. They eat young trees before they can grow, which harms woodlands. People manage deer numbers so that forests can grow back.

The IUCN's global assessment (2018, errata 2019) lists Cervus elaphus as Least Concern with an increasing trend. History has swung both ways: in Britain, forest clearance and hunting confined red deer to the Scottish Highlands, south-west England and a few scattered areas, and the Woodland Trust says they were rare by the end of the 18th century. Increasing woodland, releases and escapes from deer parks have since allowed them to spread.

Today the main concerns are high densities, which suppress woodland regeneration, and hybridization with introduced sika deer, which threatens genetic purity; in Iberia, genetic studies also caution against restocking with deer from other regions. Culling, managed stalking and careful population management aim to keep deer in balance with their habitats.