Sexual Dimorphism in the External Measurements of Black-tailed Gulls <i>Larus crassirostris</i> Breeding at Northern Niigata Prefecture

DOI
  • SHIRAI Masaki
    正会員　電力中央研究所　生物・環境化学研究部門
  • SHIMIZU Sumire
    学生会員　長岡技術科学大学大学院　生物機能工学専攻
  • HIRATA Kazuhiko
    正会員　千葉県立中央博物館　環境教育研究科
  • KOBAYASHI Soh
    非会員　電力中央研究所　生物・環境化学研究部門
  • YAMAMOTO Maki
    非会員 長岡技術科学大学大学院　生物機能工学専攻

Bibliographic Information

Other Title
  • 新潟県北部で繁殖するウミネコ<i>Larus crassirostris</i>の外部形態の性的二型

Description

<p>ABSTRACT : Sexual differences in the external measurements of adult Black-tailed Gulls Larus crassirostris (15 males and 13 females) breeding at northern Niigata Prefecture, Japan were investigated. Males were significantly larger than females in all measurements. Black-tailed gulls at this study site had large degree of sexual difference in head region (head length, bill length, and bill depth), as did individuals from other breeding areas (Kabushima and Rishiri islands). Gender was determined using the discriminant function as follows: D = 54.099 – 0.348 HL – 1.096BD.......................................................................................(1) where HL (mm) was head length and BD (mm) was bill depth. Following this equation, birds were classified as male for D < 0 and female for D > 0. This function correctly classified 100 % of the males and females.</p>

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Keywords

Details 詳細情報について

  • CRID
    1390574334767304960
  • DOI
    10.57296/jaczs.35.1_27
  • ISSN
    24369837
    13496123
  • Text Lang
    ja
  • Data Source
    • JaLC
  • Abstract License Flag
    Allowed

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