Wild Vancouver Island marmots hibernate, on average, for about 210 days of the year, generally from late September or early October until late April or early May. They generally hibernate for shorter periods in captivity. Vancouver Island marmots typically first breed at three or four years of age, although some have been observed to breed as two-year-olds. Marmots breed soon after emergence from hibernation. Gestation is thought to be approximately 30–35 days. Litter sizes average 3-4 pups, and weaned pups generally emerge above ground for the first time in early July. Systematic marmot surveys have been conducted since 1979, with variable count effort and coverage of the Island. Suitable meadows are rare compared to nearby regions of the British Columbian mainland or the Olympic peninsula of Washington State; habitat scarceness is believed to be the primary reason for the rarity of this marmot species. Most marmots live above 1000 metres elevation in meadows that face south to west. It is believed that populations expanded during the 1980s. Some natural meadows may be kept clear of invading trees by snow-creep and periodic avalanches or fire. Conservation status Causes of marmot population declines are numerous. Over the long term (i.e., periods involving thousands of years), climate changes have caused both increases and declines of open alpine habitat that constitute suitable marmot habitat. Over more recent time scales, population dynamics may have been influenced by short-term weather patterns and systematic changes in the landscape. In particular, forest clearcutting at low elevations likely altered dispersal patterns. Sub-adult marmots typically disperse from the subalpine meadows in which they were born. Dispersal involves traversing lowland conifer forests and valleys to other subalpine meadows. However, clearcutting has provided marmots with new open areas which constitute habitat. Unfortunately, rapid forest regeneration makes such man-made habitats unsuitable over a few years. One study concluded that clearcuts therefore act as a kind of population "sink" in which long-term reproduction and survival rates are reduced to the point of unsustainability One 2005 study concluded the main cause of recent decline to be predation "associated with forestry and altered predator abundance and hunting patterns". This study also revealed seasonal variations in mortality rates, where the probability of death was low during hibernation, and high in August. Major predators upon Vancouver Island marmots include golden eagles (Aquila chrysaetos), cougars (Puma concolor) and wolves (Canis lupus). The population crash may also be due to