Adaptive significance of winter pair bond in male pintail, Anas acuta
Adaptive significance of winter pair bond in male pintail, Anas acuta
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雄性针尾鸭冬季配对关系的适应性意义
作者：
Masahiko Nakamura;Takeshi Atsumi
摘要为了验证雌性优势假说对鸭冬季配对的适应意义，我们研究了北方针尾鸭的摄食和社会行为。女性优势假说假设，男性出席提供配对的女性增加社会地位和获得食物的好处，以及来自同种的骚扰较少，使他们能够花更多的时间喂养。配对的女性占主导地位的未配对的女性，但无论是时间预算的喂养和喂养的频率是显着不同的未配对和配对的女性。雌性优势假说预测，配对的雄性花在进食上的时间更少，因为它们必须密切保护自己的伴侣不受雄性同类的骚扰。配对的雄性通过追逐和啄未配对的雄性来保护它们的配偶。然而，这两个时间预算的喂养和喂养的频率显着高于配对的男性比未配对的男性。不成对的雄性在游泳时经常接近雌性。他们进行求偶表演，主要是对未配对的女性。配对的雄性花更多的时间进食，节省时间和精力在求偶。我们认为，冬季配对的男性的优势来自于有一个伴侣，并有一个增加进食频率。
Abstract To test the female-advantage hypothesis that has been proposed to explain the adaptive significance of winter pair bonds in ducks, we examined the feeding and social behaviors of the northern pintail, Anas acuta. The female-advantage hypothesis assumes that male attendance offers paired females the benefits of increased social status and access to food, as well as less harassment from conspecifics, allowing them to spend more time feeding. Paired females dominated unpaired females, but neither time budgets of feeding nor frequency of feeding was significantly different between unpaired and paired females. The female-advantage hypothesis predicts that paired males spend less time feeding because they must closely guard their partners from harassment by male conspecifics. Paired males defended their mates by chasing and pecking the unpaired males. However, both time budgets of feeding and frequency of feeding were significantly higher in paired males than in unpaired males. Unpaired males frequently approached females while swimming. They performed courtship displays, mostly toward unpaired females. Paired males spent more time feeding by saving time and energy in courtship. We consider that the advantage of winter pairing for males comes from having a mate plus having an increase in feeding frequency.