Azure-winged Magpies nest in association with Japanese Lesser Sparrowhawks where suitable nest sites are abundant

Bibliographic Information

Other Title
  • オナガは好適な営巣場所の有無をもとにツミの巣のまわりに営巣するかどうかを決定する?

Description

Azure-winged Magpies Cyanopica cyana had a tendency to nest in association with Japanese Lesser Sparrowhawks Accipiter gularis to avoid nest predation, as described in the 1990s at a study site in Tokyo (Ueta 1994). During the 2000s, however, the hawks reduced the range they defended around their nest sites (Ueta 2007), and as a result, magpies no longer concentrated their own nests around the hawk nests. In this study, I examined the nest sites of magpies from 2005 to 2011 to determine why some magpies still nested in association with hawks in spite of the reduced benefit derived from parasitizing the nest defense of the hawks'. The 1990s study showed that Azure-winged Magpies nested in sites with less leaf coverage when associated with hawk nests. Presumably, the benefits derived from the hawk nest-defense were greater than the benefits derived from abundant coverage. During the 2000s, however. magpies nested in sites with a higher rate of leaf coverage, apparently to compensate for reduced nest-defense by the hawk. Without the benefits derived from parasitizing nest defense by the hawk, magpies selected abundant camouflage as a primary characteristic during nest-site selection. The leaf coverage at magpie nest-sites in the 2000s was similar between magpies that nested in association with hawks and those that did not. The magpie nests were found near hawk nests only where optimal nest sites (i.e. high percentage of leaf coverage) for magpies were abundant. This study concludes that magpies may nest in association with hawks only when there are optimal nest sites around hawk nests.

Journal

  • Bird Research

    Bird Research 8 (0), A19-A23, 2012

    Japan Bird Research Association

Details 詳細情報について

  • CRID
    1390001205233798400
  • NII Article ID
    130002074903
  • DOI
    10.11211/birdresearch.8.a19
  • ISSN
    18801595
    18801587
  • Text Lang
    ja
  • Data Source
    • JaLC
    • CiNii Articles
  • Abstract License Flag
    Disallowed

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