SPERM COMPETITION, SPERM DEPLETION, PATERNAL CARE, AND RELATIVE TESTIS SIZE IN BIRDS
SPERM COMPETITION, SPERM DEPLETION, PATERNAL CARE, AND RELATIVE TESTIS SIZE IN BIRDS
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DOI：
10.1086/285199
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发表时间：
1991-06-01
影响因子：
2.9
通讯作者：
MOLLER, AP
中科院分区：
文献类型：
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作者：
MOLLER, AP
鸟类的睾丸质量与身体质量的比例是不同的，指数明显小于1。为了解释相对睾丸大小的变化，提出了两个假说：(1)精子竞争假说，根据这一假说，精子竞争强度高的类群的雄性睾丸比其他类群的雄性大；(2)精子耗竭假说，认为雄性交配的类群通常也有较大的睾丸。在控制了体重和系统发育的影响后，研究了睾丸质量的变化与每个雌性(作为精子竞争强度的衡量标准)和每个男性(作为精子耗尽强度的衡量标准)的交配频率的关系。相对睾丸质量的变化与雌性交配频率的变化呈正相关，且差异显著；因此，数据支持了精子竞争假说。精子耗竭假说不能解释睾丸大小的变化。睾丸相对质量的变化与社交分散度的变化呈正相关，与守护配偶行为的变化呈负相关。父亲照顾的程度与父子关系的确定性有关，这是根据配偶守卫的存在来估计的，而不是从相对的睾丸质量估计的。
Testis mass in birds scales allometrically to body mass, the exponent being significantly smaller than unity. Two hypotheses were formulated in order to account for variation in relative testis size: (1) the sperm competition hypothesis, according to which males of taxa with a high intensity of sperm competition have larger testes than males of other taxa; and (2) the sperm depletion hypothesis, which proposes that taxa in which males copulate often also have large testes. Variation in testis mass after controlling for the effects of body mass and phylogeny was investigated in relation to copulation frequency per female (as a measure of the intensity of sperm competition) and per male (as a measure of the intensity of sperm depletion). Variation in relative testis mass was positively related to variation in copulation frequency per female, and the variation was significant; the sperm competition hypothesis was therefore supported by data. The sperm depletion hypothesis could not account for variation in testis size. Variation in relative testis mass was positively correlated with variation in social dispersion and was negatively correlated with variation in mate-guarding behavior. The extent of paternal care was related to certainty of paternity as estimated from the presence of mate guarding, but not from relative testis mass.