REPRODUCTIVE EFFORT OF MALE NORTHERN ELEPHANT SEALS - ESTIMATES FROM MASS-LOSS
REPRODUCTIVE EFFORT OF MALE NORTHERN ELEPHANT SEALS - ESTIMATES FROM MASS-LOSS
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DOI：
10.1139/z90-360
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发表时间：
1990-12-01
影响因子：
1.4
通讯作者：
LEBOEUF, BJ
中科院分区：
文献类型：
--
作者：
DEUTSCH, CJ;HALEY, MP;LEBOEUF, BJ
雄性北象海豹（miounga angustirostris）繁殖努力的能量成分根据繁殖季节的质量损失进行了估算，并与优势等级和年龄相关。54头不受约束的公牛在一个平台上称重，方法是用雌海豹模型引诱它们，或者用篷布移动它们，并播放雄性攻击性的叫声。成年雄鸟到达繁殖地时体重可达2300公斤。繁殖季节，17只成虫和13只亚成虫的平均体重损失率分别为7.1 +/- 1.5 （SD）和4.6 +/- 0.8 kg / d。两个年龄组的质量损失率与体型（质量或长度）呈正相关。质量特异性质量损失率在不同年龄组之间没有差异，但在成年雄性中随着优势等级的增加而增加。在3个月的繁殖季节中，等级高的公牛（平均41.4%）比等级低的成年公牛（33.8%）的繁殖努力要大，但与年龄等级或体型无关。地位较高的雄性比地位较低的雄性交配成功率更高，消耗的能量也更多。与先前对同种雌性的研究比较表明，尽管在繁殖策略和努力时间上存在显著的性别差异，但两性在繁殖方面的大量特定精力投入是相似的。
The energetic component of reproductive effort of male northern elephant seals, Mirounga angustirostris, was estimated from mass loss over the breeding season and correlated with dominance rank and age. Fifty-four unrestrained bulls were weighed on a platform scale by luring them with a model of a female seal or moving them with a tarpaulin and using playback of male aggressive vocalizations. Adult males weighed up to 2300 kg upon arrival at the breeding rookery. Mean rate of mass loss during the breeding season was 7.1 +/- 1.5 (SD) and 4.6 +/- 0.8 kg per day for 17 adults and 13 subadults, respectively. Rate of mass loss was positively correlated with body size (mass or length) for both age-classes. Mass-specific rate of mass loss did not differ between age-classes but increased with increasing dominance rank among adult males. Reproductive effort, expressed as percentage of body mass lost over the 3-month breeding season, was greater for high-ranking bulls (mean 41.4%) than for low-ranking adults (33.8%), but was not related to age-class or body size. High-ranking males experienced higher mating success and expended more energy than subordinate males. Comparison with a previous study on conspecific females indicates that mass-specific energetic investment in reproduction is similar for both sexes, despite marked sex differences in reproductive strategy and duration of effort.