Sentences with phrase «because polar bear numbers»

That paper, which was not peer - reviewed, argued that because polar bear numbers have remained relatively stable despite faster - than - expected sea ice loss over the past decade, scientists» predictions of future population declines are flawed.

Not exact matches

It had been a different story at RAS's zoological museum a few days earlier, where she wasn't allowed to sample the bones she had come for because they were already covered with drill marks from other researchers who, like her, hoped to mine the relatively small number of ancient polar bear samples to reveal their evolutionary history.

In summary, polar bear numbers probably increased in some areas during the 1970s and 1980s, and perhaps even into the 1990s, because of greater protection from direct human mortalities.

An increasing number of polar bears are encroaching on local communities and lengthening their stays because of melting sea ice.

Polar bears are one of the most sensitive Arctic marine mammals to climate warming because they spend most of their lives on sea ice.35 Declining sea ice in northern Alaska is associated with smaller bears, probably because of less successful hunting of seals, which are themselves ice - dependent and so are projected to decline with diminishing ice and snow cover.36, 37,38,39 Although bears can give birth to cubs on sea ice, increasing numbers of female bears now come ashore in Alaska in the summer and fall40 and den on land.41 In Hudson Bay, Canada, the most studied population in the Arctic, sea ice is now absent for three weeks longer than just a few decades ago, resulting in less body fat, reduced survival of both the youngest and oldest bears, 42 and a population now estimated to be in decline43 and projected to be in jeopardy.44 Similar polar bear population declines are projected for the Beaufort Sea region.45