For the water deprivation (dehydration) phase of the experiments,
the animals were provided with graded restricted amounts of water
until they had lost 15% of their initial body mass. It was assumed that this
level of dehydration would cause maximal stimulation of physiological mechanism for water conservation .Water was then given at a level that maintained body mass at the level of 15% weight loss. Initial findings
indicated that these species would stop eating if water was withdrawn
completely for a period. Thus for this study,water was gradually reduced
from the ad libitum intake over a period of approximately one month
until the desired weight change had occurred. Details of this procedure
have been previously reported (Taylor, 1968 b; Maloiy and Taylor, 1971).
Food intake and digestibility during dehydration were measured for an
8–14 day period after the desired 15% level of dehydration had been
established, for both the constant (22 °C) and for the 12-hour cyclic
temperature (22 °C and 40 °C) periods.
Samples of food offered, and faeces produced were collected daily,weighed and frozen. A sample of the food and faeces was then dried to constant weight in a forced air-oven at 105 °C.