Russian Brown Bears

[brotherbear]

Quote: The Brown Bears also leave the high, alpine meadows and retire to the forest and thickets, where they feast on hawthorn berries, oil-rich walnuts and wild apples in preparation for their long winter lie-in.

Quote: Turning to the other end of the mammalian size scale, Brown Bears are big enough to carry large amounts of fat and barely need to hibernate properly. During autumn, they gorge themselves on the fruits of the forest - the wild strawberries, bilberries and other delicious berries that ripen at this time of year. By the time winter arrives, they are corpulent and have settled down in dens located beneath fallen trees or in the shelter of rocks - or sometimes in open places in the forest, where they build a nest-like mound of moss and other vegetation. Here, they become drowsy and sleep away the cold months for 75-195 days, depending on the region.

The bear's slumber is not true hibernation. While sleeping, their body temperature falls only slightly to 34 degrees Celsius ( 93 degress Fahrenheit ), with a consequential saving on energy reserves. However, they are tolerably alert and, if woken, are capable of bursting out of their hiding place fit to fight or flee. Nevertheless, their body chemistry does change subtly. Somehow, it seems, they are able to suppress their protein metabolism. Normally, when these compounds are broken down, urea and other nitrogenous waste are produced, and these need to be flushed out of the bloodstream by the kidneys. The change is not due simply to enforced starvation because bears prevented from feeding during the summer produce plenty of urea. But during the winter, a sleepy bear produces virtually none.

Like Polar Bears, female Brown Bears give birth to rat-sized cubs around Christmas when most of the dens are covered with a thick layer of snow. They both produce a single tiny offspring for the same reason. As bears cannot feed in the depths of winter, the cubs enter the world small enough so as not to tax the internal resources of their mothers, who have to suckle them for several months before they can go foraging. Reply