THE EFFECT OF UNCERTAINTY ON THE FOOD-INTAKE OF THE MONGOLIAN GERBIL

The effect of an unstable environment on the food intake of male adult gerbils (Meriones unguiculatus) was investigated in a laboratory set up. The main result was an increase in the intake when the environment was variable and food abundance intermediate, compared to the intake in a superabundant and stable environment. The experiment consisted of three periods. During the base-line period of the experiment all animals had superabundant food. During the next period half the animals continued in the base-line environment and the other half were presented with a variable environment with food bowls that changed places between trials. During the final period the environmental situations for the animals were reversed. Food intake was stable during the base-line period. During the second period the animals in the variable environment ate more than the animals in the base-line environment. During the third period the intake for the animals now in the variable environment increased whereas the intake in the stable environment decreased. The conclusion of the present study is that Mongolian gerbils will increase their food intake in response to variable and diminished food access. These are factors that in a natural environment could predict food scarcity.