Foraging Under Competition in Mongolian Gerbils: The Influence of Personality and Its Physiological Basis

Personality can influence animals' competitive foraging behavior. The state-behavior feedback theory suggests that these personality-driven variations may be affected by physiological states. However, the impact of personality on competitive foraging behavior within a species, as well as the physiological states associated with these variations in personality-driven foraging behavior, remains unclear. In this study, we investigated changes in foraging behavior between bold and shy Mongolian gerbils across three distinct contexts: (1) non-competitive foraging contexts, (2) a competition-introduced context at a feeding site, and (3) competitor relocation to another feeding site. We also explored the potential hormonal and energy balance factors that may influence these behavioral variations. Our results revealed that bold gerbils exhibited a consistently greater tendency to compete in two competitive contexts. Shy gerbils opted for lower-cost and more easily obtainable food resources in the competition-introduced context but displayed a similarly high tendency to compete during the competitor transfer context. Although we did not find a significant difference in fecal production, digestibility, basal metabolic rate, or blood corticosterone levels between bold and shy gerbils, bolder gerbils exhibited lower body mass and daily energy expenditure but higher food intake. Our findings indicate that Mongolian gerbils exhibited personality-driven competitive foraging strategies during intraspecific competition, which may be influenced more by differences in energy allocation than by competition pressure. This study provides empirical evidence to enhance our understanding of the mechanisms underlying personality variation in behavior and the personality-driven behavioral plasticity based on the state-behavior feedback framework.