Pygmy hippopotamus occur. The common hippopotamus gives birth and mates only in the water, but pygmy hippos mate and give birth on both land and water. Young pygmy hippos can swim almost immediately. At birth, pygmy hippos weigh 4.5–6.2 kg (9.9–13.7 lb) with males weighing about 0.25 kg (0.55 lb) more than females. Pygmy hippos are fully weaned between six and eight months of age; before weaning they do not accompany their mother when she leaves the water to forage, but instead hide in the water by themselves. The mother returns to the hiding spot about three times a day and calls
Mountain pygmy possum an underground tunnel was constructed which provided male pygmy possums with an alternative migratory route. Climate change is another serious threat to the mountain pygmy possum. "Burramys parvus" is the only Australian mammal which is completely restricted to the alpine regions. The species is well adapted to the seasonal availability of Bogong moths and other food resources. Although data from New South Wales and Victoria are still pending, preliminary models suggest that reduced survival of mountain pygmy possums can be related to declining snow cover and shorter winters. Studies conducted at Kosciuszko National Park revealed that the period of snow