Ephemeral injuries, regeneration frequencies, and intensity of the injury-producing process

Organisms may suffer sublethal injuries that lead to the loss of body parts and that leave either permanent or ephemeral scars, and these can be used to understand some aspects of the injury-producing processes, such as predation. It has been shown theoretically that for injuries that leave detectable scars throughout life, proportion of injured individuals in a population reflects the probability of fatal incidents rather than the intensity of the injury-producing process itself (Schoener in Ecology 60:1110–1115, 1979). When injuries are ephemeral and leave no detectable signature, it is shown here that frequencies of injury are a function of the intensity of the injury-producing process. Moreover, if the probability of fatality from the injury-producing process is low, as would be the case for partial or cropping predation, regeneration frequencies can be used to infer the intensity of the injury-producing process if the rate of regeneration is known.