. Ecological animal geography; an authorized, rewritten edition based on Tiergeographie auf ockologischer grundlage . Fig. 111.—Heterocephalus philippsi, X %• After Thomas. ture even after 12 hours in ice-cold water. In many animals that store fat in warm climates, the fat is localized, as in the fatty humps of camels and zebus or the fat tails and rumps of Mediterranean sheep. The Bergmann principle.—Under identical conditions all homoiothermal animals give off equal amounts of heat per unit of Two dogs with body weights of 20 kg. and kg. each were found to have surfaces of 750
. Ecological animal geography; an authorized, rewritten edition based on Tiergeographie auf ockologischer grundlage . Fig. 111.—Heterocephalus philippsi, X %• After Thomas. ture even after 12 hours in ice-cold water. In many animals that store fat in warm climates, the fat is localized, as in the fatty humps of camels and zebus or the fat tails and rumps of Mediterranean sheep. The Bergmann principle.—Under identical conditions all homoiothermal animals give off equal amounts of heat per unit of Two dogs with body weights of 20 kg. and kg. each were found to have surfaces of 7500 and 2423 sq. cm. respectively; for each kilogram there are 375 sq. cm. of surface in the large one, 757 sq. cm. in the smaller one; the heat production for 1 kg. of mass amounted to 45 calories for the large dog, 88 calories for the small one, per unit of time, which agrees closely with the corresponding value of the Thus a decrease of surface is of advantage for the maintenance of the body heat in a cold environment. Whether mammal or bird, a homoiothermal animal under other- wise similar conditions has an advantage when its body surface is pro- portionately small. In otherwise similar bodies, the larger one has the smaller surface in proportion to mass, since volume and mass increase
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Keywords: ., bookcentury1900, bookcollectionbiodive, booksubjectanimalecology
