The Great White Bear Read Online Free PDF

occasion when he and Steven Amstrup had an unexpectedly and uncomfortably close encounter with a den's inhabitant.
    In an attempt to learn more about denning behavior and den construction, USGS researchers had attached radio collars to a number of pregnant females the previous fall and, with the arrival of spring and those females' departure (as determined by the collars' GPS readings) for the sea ice, York and Amstrup visited the now-empty dens, into which they crawled and which they measured and documented.
    "In the course of that, we stumbled across some dens of non-collared bears," he recalls, "and we were always particularly careful in those instances because we didn't know if anybody was at home or not." One of those dens was between two that had been built and occupied by bears that wore collars and, with their cubs, had departed; all three were within a hundred yards of each other. Approaching by helicopter, the biologists surveyed the scene from the air and landed.
    "We shouted and hollered, threw snowballs into the den," he continues. "Steve Amstrup stuck his head into a hole and looked around. Nothing. We shut the helicopter down and got the gear out. And polar bear dens are mouse-hole-like—the entrances are much smaller than you or I could comfortably squeeze into, so we typically make them larger. And Steve was about to do that when his leg sort of popped into the tunnel and he heard a hiss. And he just about had time to say, 'Bear' before she came out. And he was standing in her exit hole. Steve went from that hole to the helicopter in nothing flat; I looked up and he was gone. I took a step backward, stepped into a crevice, and fell backward and landed on my back like a turtle."
    Like Harington, York chuckles at the memory and makes light of parts of it—a benefit of having survived the incident.
    "She saw me on my back and thought, 'Well, if you're going to make it easy...'" He smiles. "She starts walking over, and she looked enormous, and the only thought that passed through my head at the time was 'So this is how it ends.' I did have a .44; lucky for me and for the bear, it was in a holster that was completely inadequate and it was difficult to remove. My eyes were fixed on her and as she came closer, I yelled out, 'Steve!' as loudly as I could. I saw him out of the corner of my eye wheel round with his sidearm drawn, and luckily in all the commotion, the pilot saw what was happening, fired up the helicopter, and she took off."
    That the bear took so long to respond to the scientists' presence highlights the fact that, particularly once cubs are born, it is clearly more desirable to hunker down than to take action that might expose the young family to the winter elements. The fate, described earlier, that befell the cubs whose mother had denned on the pack ice may have been a consequence of the riskiness of that particular environment; but the odds of survival of cubs exposed to the winter air are no greater for cubs whose den had been on land.
    Furthermore, it seems fair to infer that mother and cubs feel secure in their little home. For example, field studies have shown that denned polar bears seem remarkably tolerant of nearby human activity, including aerial and ground traffic; only when helicopters took off or landed within a matter of feet of the den did researchers even record the bears making any kind of noise in response. Buried in their snowdrift, together in their warm, dark sanctuary, much of the time they are blissfully unaware of, and largely unconcerned by, any threats that may be passing by in the world outside.

    In the den it is warm, the chamber's insulated properties and the body heat of the bears combining to make the air inside as much as 70°F warmer than the Arctic winter outside.
    The eggs became implanted once the female found a spot for her den; a few weeks after she had made her home in the snowdrift, the cubs were born. Polar bears sometimes give birth to three cubs,