Long-term correlations in the surface behavior of dolphins

Here we study the sequences of surface behavioral patterns of dolphins ( Tursiops sp.) and find long-term correlations. We show that the long-term correlations are not of a trivial nature, i.e. they cannot be explained by the repetition of the same surface behavior many times in a row. Our findings suggest that dolphins have a long collective memory extending back at least to the 7-th past behavior. As far as we know, this is the first evidence of long-term correlations in the behavior of a non-human species.