Observational Learning in Fish, Birds, and Mammals: A Classified Bibliography Spanning Over 100 Years of Research

Observational learning does not explain improvement in predation tactics by cuttlefish (Mollusca: Cephalopoda)

When first presented with live crab prey, naive cuttlefish typically approached from the front and were often pinched. In subsequent trials, this initial group rapidly improved their prey capture techniques and attacked from above or behind the crab. Naive cuttlefish that first watched experienced conspecifics prey on crabs captured crabs without getting pinched. However, naive cuttlefish that first watched non-attacking cuttlefish in the same tank with crabs also avoided pinches, as did naive cuttlefish that were exposed only to crab odor. All three experimental groups were as successful on their first predation as the initial group was on its second predation, but the attack techniques they used were not as well developed as those of the initial group on their fifth trial. Results suggest that odor may serve as a primer for cuttlefish predatory attack behavior, perhaps by enhancing food arousal and improving attention. Practice was required for further improvements in predation techniques. We found no evidence that cuttlefish improved their predation techniques by observing conspecifics.

Observational Learning in Octopus vulgaris

Untrained Octopus vulgaris (observers) were allowed to watch conditioned Octopus(demonstrators) perform the task of selecting one of two objects that were presented simultaneously and differed only in color. After being placed in isolation, the observers, in a similar test, consistently selected the same object as did the demonstrators. This learning by observation occurred irrespective of the object chosen by the demonstrators as the positive choice and was more rapid than the learning that occurred during the conditioning of animals. The task was performed correctly without significant errors and further conditioning for 5 days. These results show that observational learning can occur in invertebrates.