REU: Energetics of Competitive Behavior

在许多生物体中，兄弟姐妹积极竞争有限的 父母的资源，往往与致命的结果，一些育雏 成员 有时这种竞争会因为公开的 侵略和建立统治等级制度。 的 牺牲近亲的自我推销行为的进化 被认为受到两个主要因素的限制：（一）遗传 幸存者和受害者之间的关系;（二）精力充沛的 与激烈的竞争性乞讨有关的费用和/或 战斗 在这项研究中，这些能源成本将被衡量 在牛背鹭（Bubulcus ibis）的三窝雏鸟中， 大量的殖民地鸟类的做法siblicide，使用“双重 标记水（稳定同位素的混合物）。 的行为 注射少量这种化合物的小鸡 在两天内的所有醒着的时间内密切监测， 之后对一个微小的血液样本的分析将揭示 能源消耗。 这种方法将应用于各种鸡 活动水平，以便每项重点活动的单位成本 （乞讨和战斗）可以确定。 这项工作将允许测试和修改 当前的家庭内部冲突理论，因为它直接解决 前提是乞讨和战斗是昂贵的。 它将 还提供关于父母照料效率的信息， 通过显示父母提供的食物能量 而不是自我保护。 在一个更实际的 这种知识和方法本身，很可能是 适用于各种稀有和濒危物种（例如，whooping 鹤，各种鹰，褐鹈鹕），它们的雏鸟竞争 致命的

In many organisms, siblings compete actively for limited parental resources, often with fatal results for some brood members. Sometimes this rivalry is accentuated by overt aggression and the establishment of dominance hierarchies. The evolution of self-promoting behavior that sacrifices close kin is believed to be constrained by two main factors: (i) the genetic relatedness between survivor and victim and (ii) the energetic costs associated with vigorous competitive begging and/or fighting. In this study, these energetic costs will be measured in three-chick broods of cattle egrets (Bubulcus ibis), an abundant colonial bird that practices siblicide, using "doubly labelled water" (a mixture of stable isotopes). The behavior of chicks injected with small amounts of this compound will be monitored closely during all waking hours over a two-day period, after which analysis of a tiny blood sample will reveal the total energy spent. This method will be applied to chicks of various activity levels, so that the unit costs of each focal activity (begging and fighting) can be determined. This exercise will allow testing and modification of current intra-family conflict theory, as it directly addresses the premise that begging and fighting are expensive. It will also provide information about the efficiency of parental care, by showing how much of parentally supplied food energy is used for growth, as opposed to self-protection. On a more practical level, this knowledge, and the approach itself, is likely to be applicable to various rare and endangered species (e.g., whooping cranes, various eagles, brown pelicans) whose nestlings compete fatally.