Elucidating effects of management practices on deer by measurements of stable isotope ratio in bone-collagen and carbonates of deer teeth

2022 Fiscal Year Final Research Report

• Project/Area Number: 19K16238
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 45040:Ecology and environment-related
• Research Institution: Research Institute of Environment, Agriculture and Fisheries, Osaka Prefecture (2020-2022); Research Institute for Humanity and Nature (2019)
• Principal Investigator: Haraguchi Takashi 地方独立行政法人大阪府立環境農林水産総合研究所(環境研究部、食と農の研究部及び水産研究部), 環境研究部, 研究員 (90721407)
• Project Period (FY): 2019-04-01 – 2023-03-31
• Keywords: 生態系管理 / 鳥獣被害対策 / 安定同位体分析 / 同位体地図（アイソスケープ） / 空間明示的な管理計画

Outline of Final Research Achievements

Aiming at applying isotopic information for the elucidation of spatiotemporal changes of crop damages by sika deer, and for the management of crop-damaging individuals, tooth and hair were collected from deer harvested in Hokusetsu district, Osaka, Japan. In order to build spatially explicit isotope mixing model in particular for nitrogen isotope as the indicator of deer consumption of fertilized crop, this project employed isoscape, a geologic map of isotope ratios for the dwarf bamboo; a deer preferred wild plant, and rice; a crop as surrogates of food sources of deer. Based on the approach, deer harvested close to cropland showed high nitrogen isotopic ratio, which was at least partly ascribed to the consumption of 15N enriched crop. As exemplified in this project, this method enabled to trace back the process to induce crop damage by the deer, based on the isotope measurements of stored deer specimens.

Free Research Field

生態学

Academic Significance and Societal Importance of the Research Achievements

農業被害の増加に伴う野生動物の効果的な管理・防除施策に対する要請を背景として、安定同位体分析による近過去のシカと現在のシカの生態を、栽培作物の利用率に着目して比較する手法を開発した。本手法により、シカが大きく個体数密度を増やす前後における食性の違いを共通手法により比較することや、客観的な指標に基づいてシカによる農作物被害の実態を評価することが可能となった。今後、地域ごとの防除実施状況などの情報と組み合わせることにより、空間明示的な防除施策の立案に活用していくことが期待される。