Data from: Post-dispersal seed recovery by animals: is it a plant- or an animal-driven process?

The ability of animals to find and consume hoarded seeds (i.e., seed recovery) is a key stage within the seed dispersal process. However, the ecology of seed recovery is still poorly understood. Here, we analyze the factors controlling seed recovery by scatter-hoarding rodents in an oak-dominated temperate forest. We examined the relative importance of intrinsic seed traits (i.e., plant-driven) and extrinsic seed factors (i.e., animal-driven) on the probability of seed recovery. We found that seed recovery is mainly driven by extrinsic seed factors, mostly related to animal behavior (pilfering frequency, microsite preference, predation risk, burial depth and cache size). Important intrinsic traits such as seed size, seed quality and seed-drop timing were, on average, of lower significance in the probability of seed recovery (2.8-times less important than extrinsic factors); only seed quality was an important intrinsic trait. On the other hand, larger and nutritionally more valuable seeds showed a removal-recovery tradeoff as they enhance seed removal and hoarding (increasing dispersal quality) but also favour seed recovery (increasing predation). We find that other mechanisms beyond seed traits (e.g. masting) are needed to decrease seed recovery and, thus, increase seed survival. We conclude that, as seed recovery is mostly driven by animal behavioural factors, it substantially differs from other previous stages of the seed dispersal process that are more dependent on seed traits. We argue that seed recovery needs further attention to advance our understanding of the ecology of seed dispersal and the role of secondary dispersers as a selective force for seeds.动物搜寻并取食贮藏种子的能力（即种子回收（seed recovery））是种子扩散过程中的关键阶段。然而，目前学界对种子回收的生态学机制仍知之甚少。本研究针对以橡树为优势种的温带森林中的散贮啮齿类（scatter-hoarding rodents），分析了其调控种子回收的影响因素。我们探究了种子内在性状（即植物驱动型）与外在种子因子（即动物驱动型）对种子回收概率的相对重要性。研究结果显示，种子回收主要受外在种子因子调控，且这些因子多与动物行为相关，包括盗食频率、微生境偏好、捕食风险、埋藏深度以及贮藏点大小。平均而言，种子大小、种子品质以及种子脱落时间等重要内在性状对种子回收概率的影响程度显著更低，仅为外在因子的1/2.8；其中仅种子品质为具有显著影响的内在性状。另一方面，个体更大、营养品质更高的种子呈现出“移除-回收”权衡效应：这类种子既能提升种子被移除与贮藏的概率（进而提高扩散质量），同时也会增加其被回收捕食的风险。本研究发现，需借助种子性状以外的其他机制（如大年结实（masting））来降低种子回收概率，进而提升种子存活率。综上，由于种子回收主要受动物行为因子调控，其与种子扩散过程中其余更多依赖种子性状的阶段存在显著差异。我们认为，未来需进一步关注种子回收过程，以深化我们对种子扩散生态学以及次级扩散者（secondary dispersers）作为种子选择压力的认知。