Long-distance seed dispersal (LDD) has strong impacts on the spatiotemporal dynamics of plants. Large animals are important LDD vectors because they regularly transport seeds of many plant species over long distances. While there is now ample evidence that behaviour varies considerably between individual animals, it is not clear to what extent inter-individual variation in behaviour alters seed dispersal by animals. We study how inter-individual variation in the movement and feeding behaviour of one of Europe’s largest herbivores (the red deer, Cervus elaphus) affects internal seed dispersal (endozoochory) of multiple plant species. We combine movement data of 21 individual deer with measurements of seed loads in the dung of the same individuals and with data on gut passage time. These data serve to parameterize a model of passive dispersal that predicts LDD in three orientations (horizontal as well as upward and downward in elevation). With this model we investigate to what extent per-seed probabilities of LDD and seed load vary between individuals and throughout the vegetation period (May–December). Subsequently, we test whether per-seed LDD probability and seed load are positively (or negatively) correlated so that more mobile animals disperse more (or less) seeds. Finally, we examine whether non-random associations between per-seed LDD probability and seed load affect the LDD of individual plant species. The studied deer dispersed viable seeds of at least 62 plant species. Deer individuals varied significantly in per-seed LDD probability and seed loads. However, more mobile animals did not disperse more or less seeds than less mobile ones. Plant species also did not differ significantly in the relationship between per-seed LDD probability and seed load. Yet plant species differed in how their seed load was distributed across deer individuals and in time, and this caused their LDD potential to differ more than twofold. For several plant species, we detected non-random associations between per-seed LDD probability and seed load that generally increased LDD potential. Inter-individual variation in movement and feeding behaviour means that certain deer are substantially more effective LDD vectors than others. This inter-individual variation reduces the reliability of LDD and increases the sensitivity of LDD to the decline of deer populations. Variation in the dispersal services of individual animals should thus be taken into account in models in order to improve LDD projections.

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个体运动和摄食行为对马鹿长距离传播种子的重要性：数据驱动模型

长距离种子传播（LDD）对植物的时空动态有很大的影响。大型动物是重要的 LDD 载体，因为它们经常长距离运输许多植物物种的种子。虽然现在有充分的证据表明个体动物之间的行为差​​异很大，但尚不清楚个体间的行为差​​异在多大程度上改变了动物的种子传播。我们研究了欧洲最大的食草动物之一（马鹿，Cervus elaphus）的运动和摄食行为的个体间差异如何影响多种植物物种的内部种子传播（内生动物）。我们将 21 只鹿个体的运动数据与同一个体粪便中种子负荷的测量值以及肠道通过时间的数据相结合。这些数据用于参数化被动扩散模型，该模型预测三个方向的 LDD（水平以及高程向上和向下）。通过这个模型，我们研究了 LDD 和种子负荷的每粒种子概率在个体之间和整个植被期（5 月至 12 月）的变化程度。随后，我们测试每个种子的 LDD 概率和种子负荷是否正（或负）相关，以便更多的移动动物散布更多（或更少）的种子。最后，我们检查每个种子 LDD 概率和种子负荷之间的非随机关联是否会影响单个植物物种的 LDD。研究的鹿散布了至少 62 种植物的可存活种子。鹿个体在每个种子 LDD 概率和种子负荷方面差异很大。然而，与活动较少的动物相比，活动较多的动物不会散布更多或更少的种子。植物物种在每粒种子 LDD 概率和种子负荷之间的关系上也没有显着差异。然而，植物物种的种子负荷在鹿个体和时间上的分布方式不同，这导致它们的 LDD 潜力差异超过两倍。对于几种植物物种，我们检测到每个种子 LDD 概率和种子负荷之间的非随机关联，这通常会增加 LDD 潜力。运动和摄食行为的个体间差异意味着某些鹿是比其他鹿更有效的 LDD 载体。这种个体间的差异降低了 LDD 的可靠性，并增加了 LDD 对鹿种群下降的敏感性。