Svensson O, Kvarnemo C
Department of Zoology, Stockholm University, Stockholm, Sweden.
J Evol Biol. 2003 Sep;16(5):896-902. doi: 10.1046/j.1420-9101.2003.00591.x.
Both natural selection and sexual selection may act on nest-building. We tested experimentally how different regimes of egg-predation and male-male competition influence nest-building before mating, using the marine fish sand goby, Pomatoschistus minutus. Males with sneaker males present built the smallest nest-openings, smaller than males held alone or with Pomatoschistus microps males (which may predate eggs and compete over nest-sites but not compete over fertilizations). Males with visual access to other nest-building males tended also to build smaller openings than males held alone or with P. microps. Males with egg-predators present built nests with openings not differing significantly from any other treatment. Our results indicate that the small nest-openings found in the sneaker male treatment are sexually selected through protection against sneaking or by female choice. Across treatments, time span before a male started to build his nest also explained variation in nest-opening width; males starting late built larger nest-openings.
自然选择和性选择都可能作用于筑巢行为。我们以海洋鱼类沙鳚（Pomatoschistus minutus）为实验对象，通过实验测试了不同的卵捕食和雄雄竞争机制如何在交配前影响筑巢行为。有偷情雄鱼存在时，雄鱼所建造的巢穴开口最小，比单独饲养的雄鱼或与细纹鳚（Pomatoschistus microps）雄鱼（可能会捕食鱼卵并争夺巢穴，但不会争夺受精机会）一起饲养的雄鱼所建造的巢穴开口都小。能够看到其他正在筑巢雄鱼的雄鱼，其所建造的巢穴开口往往也比单独饲养的雄鱼或与细纹鳚一起饲养的雄鱼所建造的巢穴开口小。有卵捕食者存在时，雄鱼所建造的巢穴开口与其他任何处理方式下的巢穴开口相比，差异均不显著。我们的研究结果表明，在有偷情雄鱼的处理方式下发现的小巢穴开口是通过防止偷情或雌性选择进行性选择的结果。在所有处理方式中，雄鱼开始筑巢前的时间跨度也解释了巢穴开口宽度的差异；开始筑巢较晚的雄鱼建造的巢穴开口较大。
