Behavioral modifications lead to disparate demographic consequences in two sympatric species

Life-history theory suggests species that typically have a large number of offspring and high adult mortality may make decisions that benefit offspring survival in exchange for increased adult risks. Such behavioral adaptations are essential to understanding how demographic performance is linked to habitat selection during this important life-history stage. Though studies have illustrated negative fitness consequences to attendant adults or potential fitness benefits to associated offspring because of adaptive habitat selection during brood rearing, equivocal relationships could arise if both aspects of this reproductive trade-off are not assessed simultaneously. To better understand how adaptive habitat selection during brood-rearing influences demographics, we studied the brood survival, attendant parental survival, and space use of two sympatric ground-nesting bird species, the northern bobwhite (hereafter: “bobwhite”; Colinus virgininanus) and scaled quail (Callipepla squamata). Dur...生活史理论（life-history theory）指出，通常具有大量后代且成体死亡率较高的物种，会做出有利于后代存活、但自身成体风险升高的决策。这类行为适应性对于理解该重要生活史阶段中，种群统计表现与栖息地选择之间的关联至关重要。尽管已有研究表明，育雏（brood rearing）期间的适应性栖息地选择会给参与育雏的成鸟带来适合度（fitness）损失，或给相关后代带来潜在适合度收益，但如果未能同时评估该繁殖权衡（reproductive trade-off）的两个方面，就可能得到模棱两可的关联结果。为了更深入地理解育雏期适应性栖息地选择如何影响种群统计特征，我们针对两种同域分布的地面筑巢鸟类——北翎鹑（下文简称"bobwhite"；*Colinus virgininanus*）以及鳞斑翎鹑（*Callipepla squamata*）——开展了研究，内容涵盖雏鸟存活率、参与育雏的成鸟存活率以及空间利用情况。（原文后续内容未完整呈现）