Resource value assessment, in which competitors adjust behaviours according to the perceived value of a contested resource, is well described in animal contests. Such assessment is usually assumed to be categorical or linear; for example, males fight more aggressively when females are present than absent, or as female fecundity increases. Here, to our knowledge for the first time, we show quadratic resource value assessment, in which resource value is highest at a certain level and decreases in either direction. The mantis shrimp Neogonodactylus bredini occupies coral rubble burrows in a size-assortative manner: individuals of a certain body size inhabit burrows of a certain size. Using mock burrows of various sizes, we tested whether mantis shrimp (1) chose burrows predicted to be the best fit for their body size and (2) were more aggressive during, endured higher costs during and were more likely to win contests over burrows predicted to be best fit. Individuals chose burrows larger than their predicted best fit burrows. In contests, intruders without burrows were more likely to evict burrow residents when the burrow was slightly smaller than the intruder's predicted best fit size. Intruder success decreased as relative burrow size increased or decreased from this value. Intruders won by delivering more strikes and by being aggressive first. In contrast to intruders, burrow residents showed little evidence of resource value assessment. A literature review revealed that quadratic resource value assessment may play a role in contests over resources from territories to parasite hosts. Therefore, our results impact theoretical models of contest behaviour and may lend insight to how contests affect resource distributions.

中文翻译：

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螳螂虾（口足类）竞赛期间的二次资源价值评估

资源价值评估，其中竞争者根据竞争资源的感知价值调整行为，在动物竞赛中得到了很好的描述。这种评估通常被假定为分类的或线性的；例如，当雌性出现时，雄性会比没有雌性时更积极地打架，或者当雌性繁殖力增加时。在这里，据我们所知，我们第一次展示了二次资源价值评估，其中资源价值在某个水平上最高，然后向任一方向下降。螳螂虾 Neogonodactylus bredini 以不同大小的方式占据珊瑚碎石洞穴：特定体型的个体居住在特定大小的洞穴中。使用各种大小的模拟洞穴，我们测试了螳螂虾是否 (1) 选择了预测最适合其体型的洞穴，以及 (2) 是否更具攻击性，期间承受了更高的成本，并且更有可能在预测最适合的洞穴的比赛中获胜。个人选择的洞穴比他们预测的最合适的洞穴大。在比赛中，当洞穴略小于入侵者预测的最合适尺寸时，没有洞穴的入侵者更有可能驱逐洞穴居民。随着相对洞穴大小从该值增加或减少，入侵者成功率降低。入侵者通过提供更多的攻击和首先采取侵略性而获胜。与入侵者相比，洞穴居民几乎没有显示出资源价值评估的证据。文献综述表明，二次资源价值评估可能在从领土到寄生虫宿主的资源争夺中发挥作用。因此，我们的结果会影响竞赛行为的理论模型，并可能有助于了解竞赛如何影响资源分配。