Maternal risk-management elucidates the evolution of reproductive adaptations in sharks by means of natural selection.

Maternal investment theory is the study of how breeding females allocate resources between offspring size and brood size to achieve reproductive success. In classical trade-off models, r/K-selection and bet-hedging selection, the primary predictors of maternal investments in offspring are population density and resource stability. In crowded, stable environments, K-selected females invest in large offspring at an equivalent cost in brood size.

Multiple maternal risk-management adaptations in the loggerhead sea turtle (Caretta caretta) mitigate clutch failure caused by catastrophic storms and predators.

Maternal risk-management, an extension of r/K selection, is an indispensable tool for understanding the natural selection pressures that shape the evolution of reproduction. Central to the construct of maternal risk-management is its definition of reproductive success as replacement fitness (w = 2), the survival of one breeding daughter to replace the female and one outbreeding son to replace her mate. Here, I apply maternal risk-management as a theoretical framework to explain multiple reproductive adaptations by loggerhead sea turtles nesting on a barrier island off the southern coast of Florida, US, from 1988 to 2004.

Extending r/K selection with a maternal risk-management model that classifies animal species into divergent natural selection categories.

Reproduction is a defining process of biological systems. Every generation, across all species, breeding females repopulate ecosystems with offspring. r/K selection was the first theory to classify animal species by linking the rates with which breeding females repopulated ecosystems, to the stability of ecosystems.

Modeling temperature-mediated fluctuation in colony size in the fire ant, Solenopsis invicta.

In the social insects, colony size is central to the survival of the queen. Two endogenous factors, worker longevity and queen's daily egg production, are known to determine maximum colony size. A third endogenous factor, duration of worker development from egg to adult, regulates the rate of colony growth.

Young fire ant workers feign death and survive aggressive neighbors.

Feigning death is a method of self-defense employed among a wide range of prey species when threatened by predator species. This paper reports on death-feigning behavior by the fire ant, Solenopsis invicta, during intraspecific aggression among neighboring fire ant workers. Days-old workers responded to aggression by death feigning, weeks-old workers responded by fleeing and months-old workers responded by fighting back.