Jones Clare R, Lorica Renee P, Villegas James M, Ramal Angelee F, Horgan Finbarr G, Singleton Grant R, Stuart Alexander M
Crop and Environmental Sciences Division, International Rice Research Institute, Metro Manila, Philippines.
Natural Resources Institute, University of Greenwich, Chatham Maritime, Kent, UK.
Integr Zool. 2017 Nov;12(6):438-445. doi: 10.1111/1749-4877.12251.
Rodents are globally important pre-harvest pests of rice. In Southeast Asia, rodent damage to growing rice crops is commonly concentrated towards the center of rice fields, away from the field edge, resulting in a clear pattern known as the "stadium effect." To further understand this behavior of rodent pests and to develop recommendations for future research and management, we examined the relation between giving-up densities (GUDs) and damage patterns. In Tanay, Luzon, Philippines, GUD trays containing pieces of coconut in a matrix of sand were placed at 4 different distances from the field edge to quantify the perceived risk of predation in a rice field pest, Rattus tanezumi. GUDs were recorded during a dry and wet season crop at the reproductive and ripening stages of rice. In addition, assessments of active burrows, tracking tile activity and rodent damage to the rice crop, were conducted in the dry season. GUDs were significantly lower in the center of the rice fields than on the field edges, suggesting that rodent damage to rice is greater in the middle of rice fields due to a lower perceived predation risk. Furthermore, this perception of predation risk (or fear) increases towards the field edge and was greatest on the rice bund, where there was no vegetation cover. We discuss the implications for rodent management and rodent damage assessments in rice fields. This is the first documented use of GUDs in a rice agro-ecosystem in Asia; thus we identify the challenges and lessons learned through this process.
啮齿动物是全球重要的水稻收获前害虫。在东南亚，啮齿动物对正在生长的水稻作物造成的损害通常集中在稻田中央，远离田边，形成一种被称为“体育场效应”的明显模式。为了进一步了解这种害虫的行为，并为未来的研究和管理制定建议，我们研究了放弃密度（GUDs）与损害模式之间的关系。在菲律宾吕宋岛的塔奈，将装有椰片且置于沙质基质中的GUD托盘放置在距离田边4个不同的位置，以量化稻田害虫——黄毛鼠所感知到的被捕食风险。在水稻的生殖期和成熟期，分别在旱季作物和雨季作物期间记录GUDs。此外，在旱季还对活跃洞穴、追踪瓦片活动以及啮齿动物对水稻作物造成的损害进行了评估。稻田中央的GUDs显著低于田边，这表明由于感知到的被捕食风险较低，啮齿动物对稻田中部水稻的损害更大。此外，这种对捕食风险（或恐惧）的感知朝着田边增加，在没有植被覆盖的田埂上最大。我们讨论了对稻田啮齿动物管理和损害评估的影响。这是亚洲首次记录在水稻农业生态系统中使用GUDs；因此，我们确定了在此过程中遇到的挑战和吸取的教训。
