Winter World by Bernd Heinrich 2003

This is a natural science book. It is very light reading and requires no technical knowledge. Here's a blurb from my favorite magazine about it.

From Scientific AmericanThere cannot be many people who have gone into a beavers' lodge. Heinrich, professor of biology at the University of Vermont, did that in his quest to see how animals survive winter. It was a summer when the pond had dried up and the beavers were not in residence, but with a flashlight and room enough to turn around, Heinrich was able to conclude that the accommodation would be quite cozy for a beaver family in winter. Similarly trying to see for himself as much as possible, he describes the winter survival strategies of many animals. He marvels in particular at the success of the golden-crowned kinglet (Regulus satrapa), a bird "scarcely larger than a ruby-throated hummingbird" that remains active all through the winters of Maine and Alaska, its life "played out on the anvil of ice and under the hammer of deprivation." The kinglet, he says, symbolizes the "astounding and ingenious strategies that animals have evolved for coping in the winter world."

My comments are in bold italics.

“Cold water is denser than hot water, and so cold water sinks as hot rises (convection). But, the change is not so uniform. Water becomes densest at 4 degrees C. As a result when lakes warm up in the springtime from 0 to 4, as the ice melts, the surface water sinks. This denser water displaces colder bottom water and its nutrients, which then rise toward the surface and feed the life above.” This is very interesting and when coupled with the fact that ice is less dense than liquid water, our water world is a very livable place indeed. Consider the state of our oceans and bodies of water if the solid state of water (ice) were more dense than its liquid state as is common with most substances. Cold water, being denser would fall down – and getting colder as it fell, it eventually would freeze solid from the bottom up. “The ecological consequence of this phenomenon would be that there would be no bodies of water in the far northern or southern regions. Sunshine in the summer would melt only the upper layers of ice, and any aspiring body of water would soon become a huge permafrosted ice lens.” Page 18

An evolutionary puzzle? “Male Manitoba red-sided garter snakes emerge from the rocky crevices before females and then wait at the periphery to intercept the females. As soon as a female emerges from the den, she is enveloped in a ball of dozens of suitors. Curiously, some of these males mimic females, and are mistaken as such by other males. Their behavior just doesn’t make sense (yet), but with more information I trust that it eventually will.” – page 230 Here’s a speculation by me: The males who mimic do not attract their brothers, who carry many of the same genes. This would require that the brothers are able to sense relatedness. If so, then the tranvestite brother would attract other competitive males, increasing his brother’s odds. Totally unproven, and the key assumptions of fraternal relatedness and sensory perception would have to be proven to lend creedence to this speculation.

“Hibernating bears metabolize mostly fat, they do not accumulate huge amounts of urea in their blood (urea is mostly produced through the metabolization of protein). What smalls they do produce they convert into creatine, which is nontoxic. Additionally, instead of becoming a toxic waste, the nitrogen wastes in hibernating bears are biochemically recycled into protein; hence no loss of muscle mass even as they don’t exercise.Thus a hibernating bear never needs to get a drink or take a leak all winter. Water is conserved because none is needed to flush out toxic wastes, and the animals stay in shape” Additionally the bears neither get bed sores nor suffer from bone loss during their long slumber, things that humans experience when immobile. “In their long evolutionary history, those (bears) who could not tolerate the rigors of prolonged inactivity were weeded out.” Pp 259-260

“1 in 3 Americans over 50 is completely sedentary. Therefore our muscles deprived of exercise become restitant to insulin that normally promotes the absorption of glucose; blood sugar reaches dangerously high levels whenever we consume sugar/starch containing products and so we risk the onset of adult diabetes. Our bodies are not adapted to inactivity. In our evolutionary history, in constrast to bears, exercise was constant. Inactivity adversely affects every organ system in the body, at least so long as we continue to eat.” p 261

“Every hour of vigorous exercise as an adult was repaid with 2 hours of additional life span. There is a limit obviously to the benefits of human exercise or else more exercise could make us immortal. Instead too much exercise increases the aging process as well. I suspect the debate of optimum exercise for longevity may relate less to how much exercise we get than to how many calories we take in versus how many we burn off. There is correlation between eating less and having a longer lifespan.” More creedence to caloric restriction. P 261

Overall I would only give this book 1 star out of 4.