HOW LONG CAN ANIMALS ABSTAIN FROM FOOD?

The most remarkable records of continued abstinence from food are to be found among the lower animals. Compared to some of these, man is a piker. It is often said that the marvels of long-continued abstinence from food reach their maximum in the "winter sleep" of several species of warm-blooded animals, but there are actually longer records than these present.

The recently produced American People's Encyclopedia tells us that the survival time in acute starvation (complete abstinence from all food save water) ranges from 21 to 117 days in dogs; rat 5 to 6 days; guinea pig 7 to 8 days; rabbit 15 days; cat 20 days; dog 38 days. There is some confusion about how long the dog may survive deprivation of food, although the matter of size may determine.

Reports of spiders undergoing incredibly long fasts, spinning webs daily, these made of substances within their bodies, until the weight of the webs so produced far outweigh the weights of the spiders at the beginning of the fast, cause me to suspect that the spiders had sources of food supply of which the observers were unaware. I find it difficult to believe that spiders have mastered the art of making something out of nothing.

Even one-celled organisms (amoeba, paramecia, etc.) can exist without food for from four to twenty-one days. Like muscle cells in a fasting man, fasting one-celled organisms only undergo a diminution in the size of the cell. These die only after the cellular reserve is exhausted. These little beings possess a food reserve which they can live on in emergencies. In the same way, each cell in the bodies of the higher animals possesses its own private food reserve.

Among vertebrates the time they can subsist without food ranges from a few days in small birds and mammals to possibly years in some reptiles. The time they can go without food depends on the amount of reserve possessed and the rate at which it is consumed. In coldblooded animals, the reserves are usually plentiful and the demand made upon them is small, so that they may fast for long intervals, without being forced to renew their stores. In warm-blooded animals, whose reserves are frequently lower and whose great activities make a greater demand upon these, the reserves are more rapidly depleted.

Among cold-blooded animals the survival time without food is usually much greater than among warm-blooded animals, since the former do not have to "burn fuel" in order to maintain a high body temperature. Snakes and other reptiles easily go for long periods without food. Snakes have been kept alive without food for almost two years. A python in captivity has been observed to go without food for a period of thirteen months. Frogs have survived sixteen months and fishes twenty months without food. Invertebrates can stand even longer periods of deprivation; the larva of the beetle Trogderma tarsale living for five years, during which time they lost 99.8 percent of their body substance. Spiders have been observed to exist without food for seventeen months and more. Fabre tells us of certain spiders that they eat no food of any kind for the first sixteen months of their lives but feast upon sunbeams. Gold fishes have been known to go for long periods without food, while proteus angeainus, an amphibian, has been known to live for years without food. In his Researches sur L'lnanition, Chossat tells us that the land tortoise of southern France, can "starve" for a year without betraying a reduction of vital energy, and that Proteus anguinus, the serpent salamander, even for a year and a half, providing the temperature of its cage is kept above the freezing point. Rhine salmon have been known to go without food for eight to fifteen months.

Oswald says: "Reptiles, with their small expenditure of vital energy, can easily survive dietetic deprivations; but bears and badgers, with an organization essentially analogous to that of the human species, and with a circulation of blood active enough to maintain the temperature of their bodies more than a hundred degrees above that of the winter storms, dispense with food for periods varying from three to five months, and at the termination of their ordeal emerge from their dens in the full possession of their physical and mental energies."--Fasting Hydropathy and Exercise, pp. 60-61. The condor, like all other vultures, is able to fast for days. It usually gorges itself, however, when it does get food.

Edwin E. Slossom, M.S., Ph. D., Director of Science Service, Washington, says in his Keeping Up With Science (Page 261): "Among the lower animals existence under inanition may extend over incredibly protracted periods. Scorpions are known to have starved for 368 days, and spiders have survived starvation for seventeen months. The larvae of small beetles have been known to live through more than five years without food, their body mass being reduced in this time to only one-sixth-hundred of what it was at the start. There is a unique record of a fresh water fish, Amia Calva, which fasted twenty months and even then had not apparently reached the end of the rope but was killed. Frogs survive starvation for sixteen months, and snakes remain alive even after two years of fasting. The longest recorded fast endured by a dog was 117 days, or nearly four months."

A. S. Pearse, Professor of Zoology at Duke University, tells us that "certain ticks can exist in an active state for as long as four years without eating anything."

Perhaps the longest periods of abstinence are seen in aestivating animals of the deserts. It should not be overlooked, also, that snails and other animals of northern deserts, that activate in the dry season and hibernate through the winter, spend most of their lives fasting.

Date: 2015-01-11; view: 864