Life History of Learning: Performance Curves of Honeybees in the Wild

The lifetime pattern of performance in a wide variety of animals including humans is remarkably similar. Initial performance is quite low, gradually increasing to a peak at about midlife, followed by a steady decrease into old age (Dukas 1998, 2008c; Helton 2007). The universal nature of the inverted-U pattern of lifetime performance suggests that common mechanisms are involved across species. Indeed the three dominant factors that can determine lifetime performance in animals that reach maximal body size at reproductive maturity are learning, physiology, and effort. Whereas life history research has addressed the issue of effort (Charlesworth & Leon 1976; Clutton-Brock 1984; Taylor 1991; Poizat et al. 1999) and there has been extensive research on physiological deterioration with age, or senescence (Rose 1991; Williams et al. 2006), learning has not been well integrated into the life history literature. Furthermore, little research effort has been devoted to the important question of how learning, physiology, and effort combine to generate lifetime patterns of performance (Dukas 2008c). To understand the evolutionary and ecological forces that have shaped the universal pattern of lifetime performance, we must quantify individual performance in natural settings. Honeybees (Apis mellifera) possess a few features that make them an ideal model system for such research. First, forager honeybees mostly focus on the single task of food collection, which contributes to colony survival and reproduction. Because bees deliver food to the hive, their foraging performance can readily be quantified (Dukas & Visscher 1994). Second, because honeybees have been used extensively in agriculture and science, a variety of techniques are available to facilitate research with this species (von Frisch 1967). Finally, although exploited extensively by humans, honeybees have retained their wild state, as indicated by the success of feral honeybees in North America (Seeley 1985, 1996). It should be noted, however, that with few exceptions (e.g., Visscher & Seeley 1982), foraging research on honeybees (A. mellifera) has been conducted in agricultural and urban settings and relatively little is known about patterns of honeybee foraging in natural settings. Correspondence Reuven Dukas, Animal Behaviour Group, Department of Psychology, Neuroscience & Behaviour, McMaster University, 1280 Main Street West, Hamilton, ON L8S 4K1, Canada. E-mail: [email protected]