Kerley G I H, Erasmus T
Department of Zoology, University of Port Elizabeth, PO Box 1600, 6000, Port Elizabeth, South Africa.
Faculty of Agriculture, University of Pretoria, 0002, Pretoria, South Africa.
Oecologia. 1991 Apr;86(2):261-267. doi: 10.1007/BF00317539.
Knowledge of the basis upon which granivores select seeds is crucial to the understanding of granivory. In this study the preferences of three rodent granivores among seeds of 11 plants from the semi-arid Karoo of South Africa were estimated, and related to the physical and chemical attributes of the seeds. Seed weights and calorific, moisture, protein, polyphenol, ash, lipid and silica contents were estimated and cell contents, soluble ash and soluble carbohydrate contents were derived from these values. These attributes were determined for both the intact seeds and the portion of the seed that is ingested by the mice. The efficiency with which mice ingested the seeds (in terms of time and mass) was recorded. All three mouse species ranked the seeds similarly, and the two species for which handling efficiency was measured did not differ in this regard. Preference hierachies were highly correlated with the rate of energy intake, as predicted by optimal foraging theory. There was no correlation between rodent preferences and the gross energy content of the seeds, emphasising the importance of measuring relevant parameters. The energy yield of the seeds calculated here, in conjunction with rodent population energy requirements and dietary data, may be used to estimate potential granivore impact on the seed production of the plant community.
了解食谷动物选择种子的依据对于理解食谷行为至关重要。在本研究中，估计了三种啮齿类食谷动物对南非半干旱卡鲁地区11种植物种子的偏好，并将其与种子的物理和化学属性相关联。估计了种子重量、热量、水分、蛋白质、多酚、灰分、脂质和二氧化硅含量，并从这些值推导出细胞内容物、可溶性灰分和可溶性碳水化合物含量。对完整种子以及小鼠摄取的种子部分都测定了这些属性。记录了小鼠摄取种子的效率（以时间和质量计）。所有三种小鼠对种子的排序相似，并且测量了处理效率的两个物种在这方面没有差异。如最佳觅食理论所预测的，偏好等级与能量摄入率高度相关。啮齿动物的偏好与种子的总能含量之间没有相关性，这强调了测量相关参数的重要性。此处计算的种子能量产量，结合啮齿动物种群能量需求和饮食数据，可用于估计食谷动物对植物群落种子生产的潜在影响。
