Social dominance, task performance and nutrition: implications for reproduction in eusocial wasps

Abstract

Dominance status is associated with individual differences in reproductive capacity in many animal societies, but the mechanisms that link social dominance to reproductive physiology are poorly understood. We propose a model for social dynamics that incorporates the nutritional costs and benefits of behavior: dominant individuals avoid energy-expensive behavior and build their nutritional reserves, thereby increasing their potential for reproduction. Greater reproductive capacity, once achieved, favors increased social dominance. To test the model, we measured relationships of females' nutrient storage and reproductive capacities with dominance status and task performance in the eusocial wasp Mischocyttarus mastigophorus. Ovary development was positively related with high levels of nutrient storage and with high rates of dominance behavior, but was not correlated with task performance. In contrast, high levels of nutrient storage were positively related with the performance of nutrient garnering and conserving tasks, but not with dominance behavior. These data support a model which places the nutritional costs of task performance as an intermediate causal link that connects dominance status with the accumulation of nutrient stores. Nutrient flow may be a general causal mechanism linking dominance status to reproductive capacity in animal societies.

Nutritional Asymmetries Are Related to Division of Labor in a Queenless Ant

“…These results are in agreement with data from honeybees where fat storage has a causal role in regulating the timing of foraging behavior [16]. Starvation has also been shown to increase foraging in some primitively eusocial wasps [27]. Future studies that manipulate individual nutritional status in D. australis , however, are necessary to determine the causality of this relationship; clearly, decreased fat storage may be a consequence rather than cause of foraging behavior.…”

On status badges and quality signals in the paper waspPolistes dominulus: body size, facial colour patterns and hierarchical rank

“…Even if a mechanism based on 'loser and winner effects' could be sufficient to explain rank-order formation in Polistes wasps (Markiewicz & O'Donnell 2001), the evolution of signals for status recognition could be advantageous for both the opponents. However, we did not find any correlations between body size of foundresses and facial pattern.…”

Percent lipid is associated with body size but not task in the bumble bee Bombus impatiens

“…Previous work has identified the markers that play an important role in different organisms, such as age in ants, honey bees, bumble bees, and wasps (Hölldobler and Wilson 1990; Jeanne 1991; O’Donnell and Jeanne 1992; Robinson 1992; O’Donnell 1995; Yerushalmi et al 2006); genes in honey bees (Ben-Shahar et al 2002); physiology in ants and honey bees (Robinson 1987; Dornhaus and Powell 2010); ambient temperature in ants (Hölldobler and Wilson 1990); dominance status in ants (Powell and Tschinkel 1999); and body size in wasps and bumble bees (Wilson 1980; Hölldobler and Wilson 1990; O’Donnell and Jeanne 1995b; Goulson et al 2002). One frequently identified factor is percent lipid, where a decrease in individual lipid stores precedes foraging in many social insects [wasps (O’Donnell and Jeanne 1995c; Markiewicz and O’Donnell 2001), honey bees (Toth et al 2005; Toth and Robinson 2005), ants (Porter and Jorgensen 1981; Tschinkel 1987; Tschinkel 1998; Blanchard et al 2000; Robinson et al 2009a, b)]. It was hypothesized that keeping foragers (who are exposed to higher predation pressures) lean may be adaptive because they are often lost to the colony (i.e., a “disposable caste” (Porter and Jorgensen 1981; O’Donnell and Jeanne 1995a)), thus reducing total energy loss to the colony.…”

“…Also, leaner foragers might be better at maneuvering in the field or lighter in flight (Porter and Jorgensen 1981; Robinson et al 2009a). However, in both circumstances, worker foraging propensity remains individually plastic and frequently affected by a combination of the above factors (O’Donnell and Jeanne 1995c; Børgesen 2000; Markiewicz and O’Donnell 2001; Toth et al 2005; Robinson et al 2009b). …”