Behavioral Dynamics of Biparental Negotiation

该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。与他人合作通常并不对所有相关方都有利，但许多物种的个体有时会以复杂的方式合作。双亲养育为简单合作的实验分析提供了一个模型系统。两个不相关的人各自为一项共同的任务做出贡献，但人们并不总是清楚他们为什么不减少投入，尤其是如果这样做会鼓励对方投入更多的话。根据进化博弈论，一个“协商模型”预测，一方努力的减少只会让另一方弥补部分损失。对鸟类父母为后代提供食物的这种预测进行的测试产生了模棱两可的结果，也许是因为个体不能总是监测配偶喂养幼鸟的数量或频率。相比之下，共同的孵化任务似乎更适合这种监测，因为转换通常涉及面对面的接触，而且鸡蛋保留了明显的温度。正如协商所预测的那样，实验诱导的雄性孵化减少导致雌性部分补偿。此外，雌性孵化的增加似乎主要发生在与雄性的社会互动之后。目前的项目是研究雄性对雌性“产卵时间”的实验操作的反应，特别是雄性是否调整了自己的孵化或对雌性的攻击。当食物在附近时，雌性会增加孵化时间，但当卵被加热时，孵化时间会缩短。研究人员已经开发出一种电子系统，仅当雌性在巢中时提供人工热量（孵化温度）。对简单合作形式的实验分析应该能提高我们对合作的总体理解，以及对强制在维持合作中的作用的理解。该项目靠近校园，为本科生和研究生在实地实验和理论生物学方面提供了出色的经验和培训机会，同时特别适合参与公共利益。

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).Cooperating with others often not does not appear advantageous to all involved parties, yet individuals in many species cooperate in sometimes complex ways. Biparental care offers a model system for experimental analysis of simple cooperation. Two unrelated individuals each contribute to a shared task, but it is not always clear why they do not invest less than they do, especially if that would encourage the partner to invest more. From evolutionary game theory, a 'negotiation model' predicts that reduced effort by one mate should trigger its partner to fill in for the deficit only partially. Tests of this prediction on avian parents provisioning their offspring have produced ambiguous results, perhaps because individuals cannot always monitor how much or how often a mate feeds the young. By contrast, the shared task of incubation seems better-suited for such monitoring because changeovers usually involve face-to-face contact and eggs retain tell-tale warmth. As predicted by negotiation, experimentally-induced reduction of male incubation in house sparrows leads to female partial compensation. Furthermore, the increases in female incubation seem to occur mainly after social interactions with the male. The current project addresses male responses to experimental manipulations of female time-on-eggs, especially whether he adjusts his own incubation or aggression toward her. Females increase incubation time when food is nearby, but reduce it when the eggs are warmed. The investigators have developed an electronic system for supplying artificial heat (at incubation temperature) only when the female is at the nest. Experimental analysis of simple forms of cooperation should improve our understanding of cooperation in general, and of the role of coercion in maintaining cooperation. Close to campus, this project offers outstanding experience and training opportunities to undergraduate and graduate students alike, both in field experimentation and theoretical biology, while being particularly amenable to engaging public interest.