Discretional cannibalism is a widespread phenomenon among lepidopteran herbivores. Herbivores encounter variation in dietary nutrient quality when foraging, which alters feeding behaviour, as well population- and trophic-level dynamics. For example, plant resistance traits directly influence patterns insect herbivores through reduced consumption of tissue increased rates cannibalism. However, t...

BACKGROUND Tyrannosaurus rex was one of the largest terrestrial carnivores of all time, and consequently its ecology and diet have been the focus of much discussion. However, there is little direct evidence of diet or feeding habits in this species. METHODOLOGY/PRINCIPAL FINDINGS Examination of museum collections has revealed four specimens of Tyrannosaurus rex that bear tooth marks made by l...

Aggression levels among individuals can severely increase under high density or shortage of crucial resources, sometimes resulting in individuals killing conspecifics. This is not uncommon in family groups of diverse taxa, where the dependent offspring compete for the limited resources provided by their parents. Killing a nest mate can relax the level of competition, and cannibalism provides a ...

During their quest to maximize fertilization success, males may be under sexual selection through male–male competition, female choice and/or sexual conflict over mating frequency. In many orb-weaving spiders, mating interactions are characterized by sexual cannibalism, which has been hypothesized to drive the evolution of male morphology and mating behaviour in this group. Here, we investigate...

The effect of kinship on larval cannibalism was examined in the marbled salamander. In separate behavioural trials, cannibalistic larvae were presented with two smaller conspecifics (a ‘prey group’), matched for size, that were (1) siblings of the cannibal, (2) non-siblings and (3) one sibling and one non-sibling (i.e. a mixture of two sibling groups); larvae were allowed to consume only one co...

Models for the evolution of cannibalism highlight the importance of asymmetries between individuals in initiating cannibalistic attacks. Studies may include measures of body size but typically group individuals into size/age classes or compare populations. Such broad comparisons may obscure the details of interactions that ultimately determine how socially contingent characteristics evolve. We ...