Maintenance mechanism of personality and its consequence in crested ibis

2020 Fiscal Year Final Research Report

• Project/Area Number: 17K07561
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Ecology/Environment
• Research Institution: Niigata University
• Principal Investigator: NAGATA Hisashi 新潟大学, 佐渡自然共生科学センター, 教授 (00202226)
• Project Period (FY): 2017-04-01 – 2021-03-31
• Keywords: 個性 / DRD4遺伝子多型 / 生存率 / 分散 / 新規開拓性 / 採餌行動

Outline of Final Research Achievements

Personality is defined as a behavioral difference among individuals. The dopamine receptor D4 (DRD4) has been identified as a candidate gene of personality in many birds. Reintroduction program of crested has been implemented in Sado Island since 2008. The Japanese population of crested ibis have only 4 haplotypes (I -IV). The relationship between DRD4 polymorphism and behavioral traits has been analyzed in the captivity and after releasing into the wild. Individuals with DRD4 haplotype IV showed higher mortality than the rest of haplotypes in crested ibis. Individuals with DRD4 haplotype IV had lower foraging efficiency and stayed near the release site. This result suggests that DRD4 polymorphism is related to the ability of novel seeking and dispersion after the release. Though DRD IV have lower fitness just after the release, it will have an advantage in stable environments. Then, there might be no difference in fitness throughout the life of ibis.

Free Research Field

動物生態学

Academic Significance and Societal Importance of the Research Achievements

トキにおいても、DRD4遺伝子多型と採餌効率、生存率に関連が認められ、DRD4が個性形質に影響を与えていることが明らかになった。DRDハプロタイプIVを持つ個体は新規探索能力が低いため、初期生存率が低いと予想されるが、分散傾向が少ないので放鳥場所での定着は高まると考えられる。今後、他の個性形質と適応度の関係を理解することにより、生物が変動環境中で適応・進化していくうえで個性形質が行動にあたえる重要性を明らかにすることが可能になる。個体のもつ特性によって放鳥方法や時期を変えることによって、全体の定着成功率を高め、最終的な再導入成功率を高める方策を採用することが可能となるであろう。