Hunting live prey is risky and thought to require specialized adaptations. Therefore, observations of predatory cannibalism in otherwise non-carnivorous animals raise questions about its function, adaptive significance and evolutionary potential. Here we document predatory cannibalism on larger conspecifics in Drosophila melanogaster larvae and address its evolutionary significance. We found th...

George R. R. Martin’s novel entitled Sandkings introduces tribes of ant-like creatures which, when locked in a terrarium deprived of food, fight for survival. The tribes differ in the color of their armor. However, in the novel, despite the extreme conditions, they’ve never attempted to kill the queens of different fractions for cannibalistic purposes. Approaching the situation from the perspec...

Dictyostelium caveatum amebas feed upon both bacteria and the amebas of other cellular slime molds. The capacity to feed extensively upon other cellular slime molds is unique to D. caveatum amebas. They are able to phagocytose amebas larger than themselves by nibbling pieces of the cells until they are small enough to ingest. Here we report the isolation from previously cloned stock cultures of...

Inclusive ¢tness theory predicts that altruism should often be directed towards reproductive relatives, but it is unclear whether individuals that are most likely to help or harm relatives are also most likely to identify kin in the ¢rst place. Here I show that species and sibships of spadefoot toad tadpoles (Spea bombifrons and S. multiplicata) that were most likely to produce an environmental...

We study a discrete time, structured population dynamic model that is motivated by recent field observations concerning certain life history strategies of colonial-nesting gulls, specifically the glaucous-winged gull (Larus glaucescens). The model focuses on mechanisms hypothesized to play key roles in a population's response to degraded environment resources, namely, increased cannibalism and ...

We hypothesize that size at hatching strongly affects population dynamics of cannibalistic fish species and is a crucial determinant of how populations respond to selective removal of large individuals (harvesting). We use a mechanistic mathematical model to study the relation between hatching size and response to harvesting mortality, using Eurasian perch (Perca fluviatilis) as a model organis...

The red-bellied black snake (Pseudechis porphyriacus) is a member of the Elapidae family and distributed on east coast Australia. species known to feed variety ectothermic prey, including frogs lizards. It also be ophiophagous (snake-feeding), stomach-content analyses suggest that P. porphyriacus exhibits cannibalistic behavior, yet this extreme case ophiophagy has rarely been documented. Here,...