Abstract
Most great earthquakes leave in their wake stories of unusual animal behaviour that preceded the main event, often by an interval long enough to be useful for warning purposes. Although much of this reported behaviour has perhaps been classified as unusual only with the benefit of hindsight, a residue of convincing stories remains and it does seem possible that animals sometimes respond to certain geophysical changes associated with the approach of rock failure, that are not monitored by instruments.
Anomalous animal behaviour is difficult to interpret, because it may arise from various causes. But this is a defect shared with other short-term precursors of great earthquakes, so study of the subject as a possible part of an imminent danger warning scheme should not be neglected on that ground alone. Mankind's past success in exploiting animal sensitivities, even before learning to understand them fully, encourages the hope that useful results will emerge.