Problem of behavioral plasticity in slave-making Amazon-ant Polyergus rufescens Latr. and in its slave-ants Formica fusca L. and Formica cinerea Mayr.

Changes in the natural behavior, expressing adaptation to cohabitation in a community, were observed in the slave-making ants P. rufescens and the slave-species F. fusca and F. cinerea. After a few raids, the initially undirected arousal evoked in the slaves by the amazons' raids, begins to acquire attributes appropriate to the situation, but completely different in both studied slave-species. F. cinerea picks up the pupae abandoned on the nest by the slave-making ants and eventually begins to wrench them away from the amazons arriving with prey. F. fusca, whose nests have openings so narrow that it prevents the mass entry of amazons with prey, begin to enlarge those openings shortly after the amazons return. After a certain number of raids, F. fusca begin to enlarge the openings immediately after the departure of the amazons for the slave-raid. The amazons, on their side, adjust soon to the specific behavior of the given slave-species; in nests with F. fusca, they make use of enlarged openings, carrying their prey through them into the nest; when F. cinerea are the slaves, most of the amazons begin to drop the pupae on the nest, and later even surrender the prey to the slaves who meet them. It is supposed that in all three species, under the influence of specific conditions there occurs the process of learning of new forms of behavior.