Chaire de recherche du Canada en biodiversité nordique, Centre d'études nordiques et Centre de la science de la biodiversité du Québec, Université du Québec à Rimouski, Rimouski, Québec, Canada G5L 3A1.
Département de biologie et Centre d'études nordiques, Université Laval, Québec, Canada G1V 0A6.
Proc Biol Sci. 2023 Aug 9;290(2004):20231154. doi: 10.1098/rspb.2023.1154.
The strength of indirect biotic interactions is difficult to quantify in the wild and can alter community composition. To investigate whether the presence of a prey species affects the population growth rate of another prey species, we quantified predator-mediated interaction strength using a multi-prey mechanistic model of predation and a population matrix model. Models were parametrized using behavioural, demographic and experimental data from a vertebrate community that includes the arctic fox (), a predator feeding on lemmings and eggs of various species such as sandpipers and geese. We show that the positive effects of the goose colony on sandpiper nesting success (due to reduction of search time for sandpiper nests) were outweighed by the negative effect of an increase in fox density. The fox numerical response was driven by changes in home range size. As a result, the net interaction from the presence of geese was negative and could lead to local exclusion of sandpipers. Our study provides a rare empirically based model that integrates mechanistic multi-species functional responses and behavioural processes underlying the predator numerical response. This is an important step forward in our ability to quantify the consequences of predation for community structure and dynamics.
间接生物相互作用的强度在野外很难量化，并且会改变群落组成。为了研究猎物物种的存在是否会影响另一种猎物物种的种群增长率，我们使用捕食的多猎物机制模型和种群矩阵模型来量化捕食者介导的相互作用强度。模型使用包括北极狐（）在内的脊椎动物群落的行为、人口统计和实验数据进行参数化，北极狐是一种以旅鼠和各种鸟类（如矶鹬和鹅）的卵为食的捕食者。我们表明，鹅群对矶鹬筑巢成功率的积极影响（由于减少了矶鹬巢穴的搜索时间）被狐狸密度增加的负面影响所抵消。狐狸的数量响应是由其活动范围大小的变化驱动的。因此，鹅的存在导致的净相互作用为负，可能导致矶鹬在当地被排斥。我们的研究提供了一个罕见的基于经验的模型，该模型整合了机制多物种功能反应和捕食者数量响应背后的行为过程。这是我们量化捕食对群落结构和动态影响的能力的重要一步。
