ensive against intruders, and will warn them off using intimidating behavior, such as beating of the tail and chattering of the teeth, and by marking their territory with their scent. One can often see an alpine marmot "standing" while they keep a look-out for potential predators or other dangers. Warnings are given, by emitting a series of loud whistles, after which members of the colony may be seen running for cover. An alpine marmot at the end of summer. Note the fattened belly. The mating season for alpine marmots occurs in the spring, right after their hibernation period comes to a close, which gives their offspring the highest possible chance of storing enough fat to survive the coming winter. Alpine marmots are able to breed once they reach an age of two years. Dominant females tend to suppress reproduction of subordinates by being antagonistic towards them while they are pregnant which causes stress and kills the young. Once the female is pregnant, she will take bedding materials (such as grass) into the burrow for when she gives birth after a gestation period of 33–34 days. Each litter consists of between one and seven babies, though this number is usually three. The babies are born blind and will grow dark fur within several days. The weaning period takes a further forty days, during which time the mother will leave the young in the burrow while she search