Meeting Abstract
Reproduction is an energetically demanding activity in all organisms. In natural populations, some individuals invest more in reproduction, while others invest more in self-maintenance. To understand this individual variation, most studies have investigated the relationship between self-maintenance and reproduction within one life history stage. However, conditions experienced at one point in an individual’s life might carry-over across stages, and have implications for future investment. The degree to which traits associated with self-maintenance during the non-breeding season predict reproductive investment during the breeding season is poorly understood. We studied free-ranging black-capped chickadees (Poecile atricapillus) to determine if individual variation in physiological traits (e.g., glucocorticoid hormone levels, oxidative stress, and immune function) during winter predict variation in reproductive traits (e.g., clutch size, egg mass, parental care behavior) during the subsequent breeding season. We present results of correlative analyses between overwintering chickadee physiological traits and reproductive traits to better understand whether self-maintenance during winter and reproductive effort represent competing functions across life history stages, or whether some individuals can maximize both, suggesting individual variation might be driven more by quality, condition, or resource acquisition. By integrating physiology and behavior, and evaluating carry-over effects across stages, we can better interpret individual variation in traits relating to self-maintenance and reproduction to gain a more complete understanding of life history strategies.
