Theory predicts intraguild predation (IGP) to be unstable despite its ubiquity in nature, prompting exploration of stabilizing mechanisms of IGP. One of the many ways IGP manifests is through inducible trophic polymorphisms in the intraguild (IG) predator, where a resource-eating predator morph competes with the intraguild (IG) prey for the shared resource while a top predator morph consumes the IG prey. Cannibalism is common in this type of system due to the top predator morph’s specialization on the trophic level below it, which includes the resource-eating predator morph. Here, we explore the consequences of inducible trophic polymorphisms in cannibal predators for IGP stability using an IGP model with and without cannibalism. We employ linear stability analysis and identify regions of coexistence based on the top predator morph’s preference for conspecifics vs. heterospecifics and the IG prey’s competitive ability relative to the resource-eating morph. Our findings reveal that preferential cannibalism (i.e., the preferential consumption of conspecifics) stabilizes the system when the IG prey and resource-eating morph have similar competitive abilities for the shared resource. Though original IGP theory finds that the IG prey must be a superior resource competitor as a general criterion for coexistence, this is not typically the case when the predator has an inducible trophic polymorphism and the resource-eating morph is specialized in resource acquisition. Preferential cannibalism may therefore be a key stabilizing mechanism in IGP systems with a cannibalistic, trophic polymorphic IG predators, providing further insight into what general mechanisms stabilize the pervasive IGP interaction.

尽管在自然界中普遍存在，但理论预测行会内掠夺（IGP）是不稳定的，这促使人们探索 IGP 的稳定机制。IGP 表现的多种方式之一是通过公会内 (IG) 捕食者中的诱导营养多态性，其中消耗资源的捕食者变体与公会内 (IG) 猎物竞争共享资源，而顶级捕食者变体则消耗 IG 猎物。同类相食在这种类型的系统中很常见，因为顶级捕食者变体在其下方的营养级上具有专门化，其中包括以资源为食的捕食者变体。在这里，我们使用有和没有同类相食的 IGP 模型探讨同类相食捕食者中诱导营养多态性对 IGP 稳定性的影响。我们采用线性稳定性分析，并根据顶级捕食者形态对同种与异种的偏好以及 IG 猎物相对于资源消耗形态的竞争能力来识别共存区域。我们的研究结果表明，当 IG 猎物和资源消耗型生物对共享资源具有相似的竞争能力时，优先同类相食（即优先消费同种动物）可以稳定系统。尽管最初的 IGP 理论认为 IG 猎物必须是优越的资源竞争者，作为共存的一般标准，但当捕食者具有可诱导的营养多态性并且资源吞噬型态专门从事资源获取时，情况通常并非如此。因此，优先同类相食可能是具有同类相食、营养多态性 IG 捕食者的 IGP 系统中的关键稳定机制，从而进一步了解稳定普遍的 IGP 相互作用的一般机制。