Regulation of Numbers of an Apparently Isolated Population of Weddell Seals (Leptonychotes weddelli)
Regulation of Numbers of an Apparently Isolated Population of Weddell Seals (Leptonychotes weddelli)
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明显孤立的威德尔海豹种群数量的调节（Leptonychotes weddelli）
DOI：
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发表时间：
1972
期刊：
影响因子：
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通讯作者：
I. Stirling
中科院分区：
文献类型：
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作者：
I. Stirling
南极洲麦克默多冰架怀特岛上的一群威德尔海豹（Leptonychotes weddelli）在地理上似乎是孤立的。它的起源仍不确定，但提到了三种解释理论。繁殖期和非繁殖期的种群在幼崽季节（10 月至 12 月中旬）分开，稍后混合，就像麦克默多海峡东部的同类一样。尽管繁殖潜力更大，但过去五个夏天每年只出生两到三只幼崽。出生率明显超过成体和亚成体的死亡率，但已知的幼崽存活率与已知的成体和亚成体死亡率处于同一数量级。 1961 年和 1968 年海冰上可见海豹的普查结果相同（11 只海豹），这也表明种群数量的稳定性。怀特岛所有海豹的极度肥胖表明，食物的供应并不能控制数量。也许冬天呼吸孔的可用性确实如此。女性之间的性内社会冲突似乎也使生殖率低于其理论潜力。
A population of Weddell seals ( Leptonychotes weddelli ) at White Island on the McMurdo Ice Shelf, Antarctica, appears to be geographically isolated. Its origin is still uncertain but three explanatory theories are mentioned. The breeding and nonbreeding fractions of the population separate during the pupping season (October to mid-December) and mix later as do their counterparts in eastern McMurdo Sound. Despite a greater reproductive potential, only two or three pups have been born annually for the past five summers. Natality clearly exceeds mortality of adults and subadults, but known survival of pups is of the same order as known mortality of adults and subadults. Censuses of seals visible on the sea ice in 1961 and 1968 were identical (11 seals), which also indicate stability in numbers of the population. The extreme fatness of all seals at White Island suggests that availability of food does not regulate numbers. Probably the availability of breathing holes in winter does. Intrasexual social strife between females also appears to lower the reproductive rate below its theoretical potential.