在哺乳动物食肉动物中,体内(IG)相互作用是常见的,可以包括内部捕食(IGP)和种间杀伤(IK),通常是不对称的,其中较大的优势物种(IGpredator)杀死较小的物种(IGprey)。根据生态学理论,IG捕食者和IGprey共存的潜力取决于IG捕食者的直接消费利益是实质性的(IGP)还是微不足道的(IK),IGprey在多大程度上是共享猎物资源的优越剥削性竞争对手,和整体生态系统生产力。我们使用资源选择模型和空间上明确的年龄和收获数据,为两个密切相关的中捕食者参与IG相互作用,美国马丁(Martesamericana;IGprey)和渔民(Pekaniapennanti;IGpredator),为了确定分销的驱动因素,划定分担和分担的区域,并探索顶点捕食者(土狼;Canislatrans)在这些相互作用中的作用。模型选择表明,渔民对这种景观的使用受到冬末非生物条件的强烈影响,但是其他自下而上(森林组成)和自上而下(土狼丰度)的因素也影响了它们的分布。总的来说,在冬末气温较暖的地方,渔民使用的可能性较高,积雪更深,生产率的衡量标准更高。马滕斯被限制在渔民使用概率较高的景观区域,土狼丰富,和生产力较低,并选择用于可能使猎物利用率最大化的森林条件。Marten年龄数据表明,在预测的同伴区域之外的青少年比例增加,这表明,在这个地区,很少有动物存活超过1.5年,支持更高密度的渔民和土狼。与不对称IG相互作用理论一致,IG捕食者(渔民和,在较小程度上,土狼)竞争性地将IGprey(martens)排除在更高的生产力之外,温和的温度栖息地,而IG捕食者和IGprey在低生产率环境中共存,非生物和生物条件的结合使IGpre成为了优越的剥削性竞争者。
Intraguild (IG) interactions are common among mammalian carnivores, can include intraguild predation (IGP) and interspecific killing (IK), and are often asymmetrical, where a larger more dominant species (IGpredator ) kills a smaller one (IGprey ). According to ecological theory, the potential for an IGpredator and IGprey to coexist depends on whether the direct consumptive benefits for the IGpredator are substantial (IGP) or insignificant (IK), the extent to which the IGprey is the superior exploitative competitor on shared prey resources, and overall ecosystem productivity. We used resource selection models and spatially explicit age and harvest data for two closely related mesopredators that engage in IG interactions, American martens (Martes americana; IGprey ) and fishers (Pekania pennanti; IGpredator ), to identify drivers of distributions, delineate areas of sympatry and allopatry, and explore the role of an apex predator (coyote; Canis latrans) on these interactions. Model selection revealed that fisher use of this landscape was strongly influenced by late winter abiotic conditions, but other bottom-up (forest composition) and top-down (coyote abundance) factors also influenced their distribution. Overall, fisher probability of use was higher where late winter temperatures were warmer, snowpack was deeper, and measures of productivity were greater. Martens were constrained to areas of the landscape where the probability of fisher use, coyote abundance, and productivity were low and selected for forest conditions that presumably maximized prey availability. Marten age data indicated an increased proportion of juveniles outside of the predicted area of sympatry, suggesting that few animals survived >1.5 years in this area that supported higher densities of fishers and coyotes. Consistent with asymmetrical IG interaction theory, the IGpredator (fishers and, to a lesser degree, coyotes) competitively excluded the IGprey (martens) from more productive, milder temperature habitats, whereas IGpredators and IGprey coexisted in low productivity environments, where a combination of abiotic and biotic conditions enabled the IGprey to be the superior exploitative competitor.