We analyze models of parental care, providing the first systematic comparison of the care given to young by one parent versus by two parents. In the Houston-Davies model of care, young always do better with two parents rather than with one parent. When one parent decides about its level of care...

Energy storage is an important component of life-history variation. A distinction is recognized between species that provision offspring using energy gained concurrently (income breeders) and those that provision offspring using energy stores accumulated at an earlier time (capital breeders)....

Many animals possess camouflage markings that reduce the risk of detection by visually hunting predators. A key aspect of camouflage involves mimicking the background against which the animal is viewed. However, most animals experience a wide variety of backgrounds and cannot change their...

The quality of a chosen partner can be one of the most significant factors affecting an animal's long-term reproductive success. We investigate optimal mate choice rules in an environment where there is both local variation in the quality of potential mates within each local mating pool and...