Shagrat herds spend their winters at the northern edge of the birch and conifer forest away to the south, where Paris was back during the human days. At the end of the long winter, they migrate back to the edge of the northern ice sheets to reach their summer grazing grounds. The females give birth in early spring, following a gestation period which lasts throughout the winter. In the middle of spring, about a third of each herd consists of youngsters.When shagrats crunch through the banks of shingle and splash through the muddy torrents, their broad feet prevent them from sinking in. Their fur is so thick that a brief immersion does them no harm - they shake off the water before it soaks into their skin and chills them. Shagrat fur is layered as well as thick. An outside coat of coarse hair provides external protection, and a tightly-packed inner layer acts as an excellent insulator. The dense underfur traps a layer of warm air next to the body as insulation, and the long waterproof guard hairs keep this fur dry (these guard hairs are hollow, and the air inside provides extra insulation). This makes two layers of fur. Thus, a shagrat is doubly insulated against the ice age winters.
Out in the open, shagrats can survive as low as -50. The herds have to cover large distances each day to find sparse patches of grazing.
When searching for food after returning to the open tundra, shagrat herds spread out across meadows and root about, pushing rocks over with their strong forelegs to reveal the soil beneath. The big claws on their forefeet dig into the soil to reach underground grass stems and the roots of heather and willow. Their marmot ancestors were burrowing animals and so their front feet were already well adapted for this kind of foraging. Claws scrape the ground, and plants are uprooted with broad chisel teeth.
If one member of the herd smells danger, it barks a warning and the whole herd leaps to attention. There are few dangerous large animals in the tundra, but shagrats still have things to worry about. An unsettled herd assembles in an open space and, instinctively, the youngsters huddle in the middle. The adults surround them in a defensive formation, all facing outwards. This behavior is very much like that of musk oxen, which employed an identical strategy when under threat from Arctic wolves. The shagrats' chief enemy is the snowstalker, which can follow a herd for days. When such a predator is present, the shagrats bunch up even more closely, narrowing their eyes and baring their teeth, hissing in threat.
When a blizzard (that can reach a temperate of -60) strikes, visibility can drop and traveling shagrats can be vulnerable to snowstalkers that use the whiteness all around as cover when stalking. If a shagrat gets tired, ill or weak and falls behind the herd, it is in serious trouble.