Grauer Jennifer A, Twining Joshua P, Lejeune Manigandan, Frair Jacqueline L, Schuler Krysten L, Kramer David W, Fuller Angela K
New York Cooperative Fish and Wildlife Research Unit, Department of Natural Resources and the Environment, Cornell University, Ithaca, New York, USA.
Department of Fisheries, Wildlife, and Conservation Sciences, Oregon State University, Corvallis, Oregon, USA.
Ecol Lett. 2025 Jun;28(6):e70159. doi: 10.1111/ele.70159.
Species interactions structure ecological communities through direct and indirect pathways with ecosystem-wide implications. Despite mounting interest in the importance of indirect interactions, empirical evidence remains limited. Here, we demonstrate the critical role of parasite-mediated competition in driving community outcomes in a multi-species system of conservation and management concern. We leveraged 2 years of detection/non-detection data of moose (Alces alces) and white-tailed deer (Odocoileus virginianus) and parasite loads in faecal samples within a hierarchical abundance-mediated interaction model to test hypotheses regarding interactions between these cervids and their shared parasites (Parelaphostrongylus tenuis, Fascioloides magna). We demonstrate that moose occupancy was limited by parasite-mediated competition, with no evidence of population-level effects of direct competitive interactions between moose and white-tailed deer. Such evidence of the importance of indirect interactions and resulting community outcomes is critical for species conservation and managing range contractions due to increasing pressures from habitat loss, disease and climate change.
物种间相互作用通过直接和间接途径构建生态群落，并对整个生态系统产生影响。尽管人们对间接相互作用的重要性兴趣日增，但实证证据仍然有限。在此，我们证明了寄生虫介导的竞争在一个具有保护和管理意义的多物种系统中驱动群落结果方面的关键作用。我们利用了两年间驼鹿（Alces alces）和白尾鹿（Odocoileus virginianus）的检测/未检测数据以及粪便样本中的寄生虫负荷，在一个分层的丰度介导相互作用模型中，来检验关于这些鹿科动物与其共有的寄生虫（细颈囊尾蚴，巨片形吸虫）之间相互作用的假设。我们证明，驼鹿的占有率受到寄生虫介导的竞争限制，没有证据表明驼鹿和白尾鹿之间存在直接竞争相互作用对种群水平的影响。这种关于间接相互作用的重要性及其导致的群落结果的证据，对于物种保护以及应对因栖息地丧失、疾病和气候变化带来的日益增加的压力而管理分布范围收缩至关重要。
