Institute of Ecology and Geobotany, School of Ecology and Environmental Sciences, Yunnan University, Kunming, China.
Key Laboratory of Poyang Lake Wetland and Watershed Research (Ministry of Education), College of Life Sciences, Jiangxi Normal University, Nanchang, China.
Integr Zool. 2020 Nov;15(6):569-577. doi: 10.1111/1749-4877.12473. Epub 2020 Jul 30.
Neighborhood effects on seed predation and dispersal processes are usually seed-characteristic-dependent; however, how seeds with certain characteristics affect the foraging behavior of rodents in relation to other seeds nearby is unclear. Because large differences in seed characteristics between neighboring seeds may lead to significant differences in rodent foraging preferences, we hypothesized that neighborhood effects were more likely to be detected when paired seeds differed in seed characteristics. We investigated the foraging decisions of two rodent species, the red spiny rat Maxomys surifer and the Chinese white-bellied rat Niviventer confucianus, in semi-natural enclosures by presenting them with artificial seeds containing different levels of tannin (0, 3%, and 6% tannin). Both rodents showed similar preferences and preferentially consumed high-tannin seeds (6% tannin) and scatter hoarded low-tannin seeds (0 tannin). The scatter hoarding of low-tannin (0 tannin) and high-tannin (6% tannin) seeds was significantly higher when these seeds were neighboring higher-tannin seeds than when they neighbored lower-tannin seeds, whereas the scatter hoarding of intermediate-tannin seeds (3% tannin) varied little when they had different neighbors. High-tannin-seed (6% tannin) scatter hoarding was lowest when they neighbored low-tannin seeds (0 tannin), while low-tannin-seed (0 tannin) scatter hoarding was highest when they neighbored high-tannin seeds (6% tannin). Therefore, the seeds that the rodents scatter hoarded were next to (neighbored) seeds that they preferred to eat immediately, and vice versa. Our findings suggest that seed neighborhood effects affect rodent foraging behavior and the relationship between plants and rodents, and may have a profound effect on the regeneration and spatial structure of plant communities.
邻域效应对种子捕食和扩散过程的影响通常依赖于种子特性；然而，具有某些特征的种子如何影响啮齿动物对附近其他种子的觅食行为尚不清楚。因为相邻种子之间的种子特性差异很大可能导致啮齿动物觅食偏好的显著差异，所以我们假设当配对种子在种子特性上存在差异时，更有可能检测到邻域效应。我们通过在半自然围场中向两种啮齿动物，红刺鼠 Maxomys surifer 和中华白腹鼠 Niviventer confucianus，提供含有不同水平单宁（0、3%和 6%单宁）的人工种子，研究了它们的觅食决策。这两种啮齿动物表现出相似的偏好，优先食用高单宁（6%单宁）种子，并分散贮藏低单宁（0 单宁）种子。当低单宁（0 单宁）和高单宁（6%单宁）种子与高单宁种子相邻时，它们的分散贮藏量明显高于与低单宁种子相邻时，而中间单宁种子（3%单宁）的分散贮藏量在与不同邻居相邻时变化不大。当高单宁种子（6%单宁）与低单宁种子（0 单宁）相邻时，其分散贮藏量最低，而当低单宁种子（0 单宁）与高单宁种子（6%单宁）相邻时，其分散贮藏量最高。因此，啮齿动物分散贮藏的种子是它们最想立即食用的种子的邻居，反之亦然。我们的研究结果表明，种子邻域效应对啮齿动物的觅食行为和植物与啮齿动物之间的关系有影响，可能对植物群落的再生和空间结构产生深远影响。
