Da. Case et al., PIGEONS PREFERENCE FOR VARIABLE-INTERVAL WATER REINFORCEMENT UNDER WIDELY VARIED WATER BUDGETS, Journal of the experimental analysis of behavior, 64(3), 1995, pp. 299-311
Water budget of pigeons was varied to assess the dependence of risk-se
nsitive preferences upon economic context such as has been reported fo
r energy-budget manipulations with small animals in behavioral ecology
research. Fixed- and variable-interval terminal-link water schedules
reinforced choice between equal variable-interval initial-link schedul
es arranged on two pecking keys. While keeping a severely restrictive
budget the same across three phases of the experiment, a contrasting d
istinct ample budget was arranged in each. To mimic typical methods in
behavioral ecology studies, in each ample budget a more than three-fo
ld increase in amount of water per reinforcer presentation was institu
ted simultaneously with significantly increased overall access to wate
r. Total choice response rates plummeted in the ample budgets, and bod
y weights either increased significantly or remained unchanged in diff
erent phases as expected by the nature of the different manipulations.
Clear preferences for the variable-interval schedule were found throu
ghout the experiment, except for rare instances of key bias. The resul
ts agree with similar operant food-reinforcement studies and extend co
nditions under which risk preference apparently does not depend upon e
conomic context.