College of Life Sciences, Jiangxi Normal University, Nanchang, Jiangxi, China; College of Agriculture, Henan University of Science and Technology, Luoyang, Henan, China.
College of Agriculture, Henan University of Science and Technology, Luoyang, Henan, China.
PLoS One. 2014 Mar 19;9(3):e92544. doi: 10.1371/journal.pone.0092544. eCollection 2014.
Selecting seeds for long-term storage is a key factor for food hoarding animals. Siberian chipmunks (Tamias sibiricus) remove the pericarp and scatter hoard sound acorns of Quercus mongolica over those that are insect-infested to maximize returns from caches. We have no knowledge of whether these chipmunks remove the pericarp from acorns of other species of oaks and if this behavior benefits seedling establishment. In this study, we tested whether Siberian chipmunks engage in this behavior with acorns of three other Chinese oak species, Q. variabilis, Q. aliena and Q. serrata var. brevipetiolata, and how the dispersal and germination of these acorns are affected. Our results show that when chipmunks were provided with sound and infested acorns of Quercus variabilis, Q. aliena and Q. serrata var. brevipetiolata, the two types were equally harvested and dispersed. This preference suggests that Siberian chipmunks are incapable of distinguishing between sound and insect-infested acorns. However, Siberian chipmunks removed the pericarp from acorns of these three oak species prior to dispersing and caching them. Consequently, significantly more sound acorns were scatter hoarded and more infested acorns were immediately consumed. Additionally, indoor germination experiments showed that pericarp removal by chipmunks promoted acorn germination while artificial removal showed no significant effect. Our results show that pericarp removal allows Siberian chipmunks to effectively discriminate against insect-infested acorns and may represent an adaptive behavior for cache management. Because of the germination patterns of pericarp-removed acorns, we argue that the foraging behavior of Siberian chipmunks could have potential impacts on the dispersal and germination of acorns from various oak species.
选择用于长期储存的种子是食物贮藏动物的关键因素。西伯利亚花鼠（Tamias sibiricus）会去除果皮并将受虫害的蒙古栎（Quercus mongolica）橡实与未受虫害的橡实分开贮藏，以最大限度地提高贮藏的回报。我们不知道这些花鼠是否会从其他栎属树种的橡实中去除果皮，以及这种行为是否有利于幼苗的建立。在这项研究中，我们测试了西伯利亚花鼠是否会对三种中国栎属树种的橡实，即麻栎（Quercus variabilis）、栓皮栎（Quercus aliena）和辽东栎（Quercus serrata var. brevipetiolata），表现出这种行为，以及这些橡实的传播和萌发会受到怎样的影响。我们的结果表明，当花鼠提供了健康的和受虫害的麻栎、栓皮栎和辽东栎橡实时，这两种橡实都会被同等地收获和传播。这种偏好表明，西伯利亚花鼠无法区分健康的和受虫害的橡实。然而，西伯利亚花鼠在传播和贮藏这些橡实之前会去除果皮。因此，更多的健康橡实被散布贮藏，更多的受虫害的橡实被立即消耗。此外，室内萌发实验表明，花鼠去除果皮促进了橡实的萌发，而人工去除果皮则没有显著效果。我们的研究结果表明，果皮的去除使西伯利亚花鼠能够有效地识别受虫害的橡实，这可能是一种用于贮藏管理的适应性行为。由于去除果皮的橡实的萌发模式，我们认为西伯利亚花鼠的觅食行为可能对各种栎属树种的橡实的传播和萌发产生潜在影响。
