Dubois Frédérique
Département de Sciences Biologiques Université de Montréal Montreal Quebec Canada.
Ecol Evol. 2023 Oct 4;13(10):e10578. doi: 10.1002/ece3.10578. eCollection 2023 Oct.
Individuals generally differ in their ability to perform challenging behaviours, but the causes of such variability remain incompletely understood. Because animals can usually use different behavioural tactics to achieve their goals, we might expect individual differences in skill to be maintained when the available tactics require different abilities to perform well. To explore this idea, I used the producer-scrounger (PS) paradigm, which considers interactions between foragers that may either invest effort in searching for resources (i.e. produce) or exploit others' discoveries (i.e. scrounge). Specifically, I tested whether individual differences in cognitive traits (i.e. the ability to find food) might result from a trade-off with competitiveness (i.e. the ability to steal food) that would exert disruptive selection pressure and, as such, might explain the coexistence of condition-dependent foraging tactics. If individuals differ in their competitiveness, with strong contestants being better able to monopolize food resources (and hence to scrounge), the model predicts that strong and weak competitors should rely more on scrounging and producing, respectively, especially when the finder's advantage is low. These findings indicate that the existence of individual differences in competitive abilities may be sufficient to explain short-term individual foraging tactic specialization. Yet, the degree of behavioural specialization is expected to depend on both the social and ecological context. Furthermore, persistent phenotypic differences, that are necessary for stable individual specialization, require the existence of a trade-off between competitive abilities that enable greater success as scroungers and cognitive abilities that are associated with better efficiency to detect and/or capture prey and, as such, enable greater success as producers. Therefore, this study further highlights the importance of considering the existence of alternative tactics to measure and predict the evolution of traits, including cognitive traits, within populations.
个体在执行具有挑战性的行为能力上通常存在差异，但这种变异性的原因仍未完全被理解。由于动物通常可以使用不同的行为策略来实现其目标，我们可能会预期，当可用策略需要不同能力才能良好执行时，技能上的个体差异会得以维持。为了探究这一想法，我采用了生产者 - 窃取者（PS）范式，该范式考虑了觅食者之间的相互作用，这些觅食者可能会投入精力寻找资源（即生产）或利用他人的发现（即窃取）。具体而言，我测试了认知特征（即寻找食物的能力）的个体差异是否可能源于与竞争力（即窃取食物的能力）的权衡，这种权衡会施加破坏性选择压力，因此可能解释依赖条件的觅食策略的共存。如果个体在竞争力上存在差异，强大的竞争者更有能力垄断食物资源（从而进行窃取），该模型预测，强竞争者和弱竞争者应该分别更多地依赖窃取和生产，尤其是在发现者优势较低时。这些发现表明，竞争能力的个体差异的存在可能足以解释短期的个体觅食策略专业化。然而，行为专业化的程度预计将取决于社会和生态背景。此外，稳定的个体专业化所需的持续表型差异，需要在作为窃取者能取得更大成功的竞争能力与与更好地检测和/或捕获猎物的效率相关联、从而作为生产者能取得更大成功的认知能力之间存在权衡。因此，本研究进一步强调了考虑替代策略的存在对于测量和预测种群内包括认知特征在内的性状进化的重要性。
