linguistic:voice_change, structural:expansion, quality:correction
Decline in population

Since the 1990s, moose populations have declined dramatically in much of temperate North America, although they remain stable in Arctic and subarctic regions. The exact causes of specific die-offs are not determined, but most documented mortality events were due to wolf predation, bacterial infection due to injuries sustained from predators, and parasites from white-tailed deer to which moose have not developed a natural defense, such as liver flukes, brain worms and winter tick infestations. Predation of moose calves by brown bear is also significant. Landscape change from salvage logging of forest damage caused by the mountain pine beetle has resulted in greater foraging in logged areas by female moose, and this is the lead hypothesis as to why the moose population is declining in eastern North American forests, as this likely leads to increased predation. An alternate hypotheses among biologists for generalized, nonhunting declines in moose populations at the southern extent of their range is increasing heat stress brought on by the rapid seasonal temperature upswings as a result of human-induced climate change. Biologists studying moose populations typically use warm-season, heat-stress thresholds of between 14 and 24 °C (57 and 75 °F). However, the minor average temperature increase of 0.83–1.11 °C (1.5–2 °F), over the last 100 years, has resulted in milder winters that induce favorable conditions for ticks, parasites and other invasive species to flourish within the southern range of moose habitat in North America. The moose population in New Hampshire fell from 7,500 in the early 2000s to a 2014 estimate of 4,000 and in Vermont the numbers were down to 2,200 from a high of 5,000 animals in 2005. Much of the decline has been attributed to the winter tick, which, between 2017 and 2019, accounted for 74% of all winter mortality and 91% of winter calf deaths in Vermont. Moose with heavy tick infections will rub their fur down to the skin raw trying to get the ticks off, making them look white when their outer coat rubs off. Locals call them ghost moose. Loss of the insulating winter coat through attempts to rid the moose of winter tick increases the risk of hypothermia in winter.