A new study has revealed the startling predicament of polar bears as they’re forced to swim long distances for survival owing to dwindling arctic sea ice. Scientists from the University of Alberta and Environment and Climate Change Canada proceeded to document polar bear swimming behaviors and revealed that more and more animals have begun to cover tremendously long distances. According to experts, this perturbing pattern of marathon swims attempted by polar bears in the Beaufort Sea in particular is indicative of the staggering repercussions of climactic warming.
Researchers associated with the study, published in a recent issue of the journal Ecography, had employed “satellite-linked telemetry” to map polar bear populations in the Beaufort Sea and Hudson Bay. They determined that nearly 70 percent of the tracked adult females in the region swam over 30 miles at least once.
Lead author Nicholas Pilfold sees these behaviors as an ominous impact of global climate change.
“The pattern of long-distance swimming by polar bears in the Beaufort Sea shows the fingerprint of climate change. Swims are occurring more often, in association with sea ice melting faster and moving farther from shore in the summer. Recent studies indicate that swimming may be energetically costly to polar bears. Given the continued trend of sea ice loss, we recognize that an increased frequency in the need to engage in this behavior may have serious implications for populations of polar bears living around the Arctic Basin.”
Over the years the continuous loss of sea ice around the arctic belt has been unprecedented and has led to the polar bear being listed as a globally threatened species. Polar bears are losing valuable habitats at a tremendously fast pace and are therefore being forced to look for food sources elsewhere. These glorious animals essentially thrive on seal populations commonly nestled above the surface of arctic sea ice. The receding ice drastically reduces their likelihood of successfully securing prey, inhibits hunting, and ultimately puts into enormous peril their chances of survival.
Many studies have previously noted that polar bears tend to compensate for lack of nutrition by conserving energy and reducing their metabolic rate. This would mean that attempting to swim immensely long distances in search of food can hardly enable these animals to sustain themselves particularly when food sources are scarce and successful hunting attempts are infrequent.
Polar bears are prolific swimmers. They have been known to swim across extensive swathes of sea water with relative ease. Many adult polar bears are capable of overcoming unbelievably long distances at a time. They’ve been observed swimming consistently for 100 km as well as enduring increasingly longer swims in the freezing arctic waters. Research has shown that they are also capable of temporarily cooling themselves from time to time in order to survive these long and exhausting journeys. However, the same can hardly be said about polar bear cubs. There have been many instances where female bears have managed to survive these swims for weeks but at the cost of their cubs.
According to Andrew Derocher, a University of Alberta biologist who co-authored the study, the loss of crucial habitat as well as feeding ground has forced the polar bears to undertake long and often dangerous sea journeys.
‘More and more animals in the population are being caught in places that they just can’t stay. Polar bears are well adapted to swimming,but of course, not all polar bears are created equal when it comes to the ability to swim.”
While the study could not determine whether any of these long-distance swims fatally impacted adult polar bears, researchers were uncertain whether cubs accompanying the adult bears could actually have survived these marathon swims for days in search for stable ground. The study did, however, note that female polar bears if and when accompanied by cubs were attempting far less long-distance swims. Other long-term studies of polar bears in the southern Beaufort Sea have revealed a manifest drop in the survival rate of cubs and a decrease in the skull size of both adult males and cubs, possibly owing to a progressive lack of nutrition.
Experts maintain that sea ice breakup over extended periods has contributed to a drastic drop in the polar bear’s food supply, which sometimes forces it to encroach upon human-inhabited territories in a desperate bid to fetch food through secondary means. For years, researchers have been observing the western Hudson Bay territory and other polar bear habitats, to comprehend how climactic warming could influence bear behavior in other parts of the arctic as well.
According to a report published last year, a staggering 40 percent drop in polar bear population in Southern Beaufort Sea was recorded. Another study investigating a dramatic decline in polar bear numbers in the northeast Alaska and Canada territories attributed them to continuously receding sea ice levels further exasperated by global warming.
Polar bears are commonly characterized as marine animals owing to the amount of time they spend on the Arctic sea ice. Their heavy layer of blubber helps insulate them from piercing winds and the overall frigid and often hostile arctic climate. Masters swimmers, they can sustain a pace of six miles per hour as they deftly use their front paws for paddling for long distances.
However, their disintegrating habitats and disrupted food chain have forced these magnificent animals to undertake strenuous journeys across endless swathes of the Arctic in their desperate bid for sustenance. Scientists are now beginning to fear that these extreme circumstances would at some point in near time threaten to push the species ever closer to the brink of extinction.
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