Investigation of factors affecting population decline of Slaty-backed Gulls: impact assessment of human-derived food resource

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K06083
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 39060:Conservation of biological resources-related
• Research Institution: Waseda University
• Principal Investigator: Kazama Kentaro 早稲田大学, 人間科学学術院, 准教授 (60726842)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 漁業廃棄物 / カモメ類 / 人間活動の影響 / 採餌効率 / バイオロギング / 漁業資源 / 絶滅危惧

Outline of Final Research Achievements

Slaty-backed gulls whose population is rapidly decreasing in recent years, often use artificial diets such as fisheries or human garbage. In general, a strong depnedent on the artificial diets with lower energetic values may reduce the breeding performance of this species, but its effects were not well understood. In this study, GPS tracking and breeding monitoring were conducted to clarify the effects of the dependent on artificial diets of this species on breeding performance at the individual level. When individuals foraged in an artificial environment such as a fishing port or a fisheries processing plant, it took a long time from departure the nest to return back to the nest with diets, and the weight and energetic value of the diets was small. These results indicated that the feeding efficiency is reduced and the breeding performance is potentially reduced when individuals forage the artificial diets.

Free Research Field

生物資源保全学

Academic Significance and Societal Importance of the Research Achievements

人間活動を起源とする餌資源が野生動物に及ぼすインパクトの解明は世界的な課題となっているが、実証的研究は少ない。本研究ではオオセグロカモメを対象としてGPS追跡と繁殖モニタリング調査を併用することで、漁業廃棄物や残飯などの人間活動起源の餌の利用が潜在的に本種の繁殖に負の影響を及ぼし、個体数減少の一因になり得ることをはじめて明らかにした。