Higher rates of pre‐breeding condition gain positively impacts clutch size: a mechanistic test of the condition‐dependent individual optimization model

1. A combination of timing of and body condition (i.e., mass) at arrival on the breeding grounds interact to influence the optimal combination of the timing of reproduction and clutch size in migratory species. This relationship has been formalized by Rowe et al. in a condition-dependent individual optimization model (American Naturalist, 1994, 143, 689-722), which has been empirically tested and validated in avian species with a capital-based breeding strategy. 2. This model makes a key, but currently untested prediction; that variation in the rate of body condition gain will shift the optimal combination of laying date and clutch size. This prediction is essential because it implies that individuals can compensate for the challenges associated with late timing of arrival or poor body condition at arrival on the breeding grounds through adjustment of their life history investment decisions, in an attempt to maximize fitness. 3. Using an 11-year data set in arctic-nesting common eiders ...

1. 迁徙物种抵达繁殖地时的到达时间与身体状况（即体重）的交互作用，会影响其繁殖时机与窝卵数（clutch size）的最优组合。罗（Rowe）等人已通过条件依赖个体优化模型（《美国博物学家》，1994年，第143卷，689-722页）将该关系形式化，该模型已在采用资本型繁殖策略的鸟类物种中得到实证检验与验证。2. 该模型提出了一项关键但目前尚未得到验证的预测：身体状况提升速率的变化，会改变产卵日期与窝卵数的最优组合。该预测至关重要，因为它意味着个体可通过调整其生活史投资决策，来弥补因抵达繁殖地时间过晚或身体状况不佳所带来的生存挑战，以期最大化进化适合度（fitness）。3. 本研究采用了一项针对北极筑巢普通绒鸭的11年数据集……