Massive emigrations of the frog Rana pipiens pipiens Schreber have been recorded from large sloughs in northwestern Iowa. To investigate the possible ecological causes for this movement, two sets of laboratory experiments were done. A simulated slough was constructed in a large concrete tank and stocked with vegetation and a population of maturing tadpoles. As the time came for the emigration in the field, the experimental population, under the regulated laboratory conditions, had matured and emigrated in a way parallel to the natural situation. In other experiments, emigrations were determined for populations of juvenile frogs, one of which was five times the size of the other. The rate of movement was almost identical in the two groups, suggesting that population pressures do not stimulate movement. The precise correspondence of activity in the artificial slough with that in the field, as well as the apparent density-unrelated response to population density, indicate that the stimuli to this emigration behavior are internal rather than environmental.
Proceedings of the Iowa Academy of Science
©1965 Iowa Academy of Science, Inc.
Bovbjerg, Richard V.
"Experimental Studies on the Dispersal of the Frog, Rana Pipiens,"
Proceedings of the Iowa Academy of Science, 72(1), 412-418.
Available at: https://scholarworks.uni.edu/pias/vol72/iss1/61