Quantitative evaluation of the role of each animal in the decomposition process of large mammal carcasses and development of a method

2022 Fiscal Year Final Research Report

• Project/Area Number: 21K19858
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 64:Environmental conservation measure and related fields
• Research Institution: Tokyo University of Agriculture and Technology
• Principal Investigator: Koike Shinsuke 東京農工大学, (連合)農学研究科(研究院), 教授 (40514865)
• Project Period (FY): 2021-07-09 – 2023-03-31
• Keywords: 動物遺体 / 分解

Outline of Final Research Achievements

A variety of organisms are involved in the decomposition of large animal carcasses. Among them, carrion-eating dipteran larvae contribute greatly to the decomposition of carcasses and shorten the decomposition period, as they decompose 90% of carcasses in the absence of vertebrates. This study aims to clarify the seasonal differences in the decomposition period of large vertebrate carcasses by dipteran larvae and the factors that cause these differences. The experimental results showed that the time required for decomposition increased in spring and fall and decreased in summer. In addition, the rate of decrease in carcass weight relative to effective integrated time was almost constant in summer and fall, whereas it increased significantly in spring, suggesting that not only temperature but also the species composition at the time has a significant effect on larval activity.

Free Research Field

生態学

Academic Significance and Societal Importance of the Research Achievements

大型動物死体の分解には、多様な生物が関与しているが、中でも死肉食性双翅目幼虫は、脊椎動物不在下で死体の9割を分解するなど、死体分解に大きく寄与するとともに、分解期間を短縮させる。また、双翅目幼虫の出現有無や分解速度は季節により変化することが知られる。その理由として、双翅目幼虫の季節による分解速度の差は温度や湿度、種組成によるものだと考えられていたが、それらの要因を明らかにすることが出来た。本結果で得られた知見は、今後のシカの管理、特に駆除残滓の取り扱いを検討するうえで重要な知見となるであろう。