Possible non-offspring nursing in the southern right whale, Eubalaena australis
Possible non-offspring nursing in the southern right whale, Eubalaena australis
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南露脊鲸 Eubalaena australis 可能正在哺乳非后代
DOI：
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发表时间：
2015
期刊：
影响因子：
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通讯作者：
Katja Vinding
中科院分区：
文献类型：
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作者：
P. Best;S. Elwen;P. Palsbøll;M. Thornton;Evan Austin;Katja Vinding
在南半球的冬季，成年雌性南露脊鲸进入南非沿海沃茨生产和抚养它们的幼崽。大部分的分娩时间为4个月，雌性在特定的沿海地区或育儿场聚集，最长可达105天。此时，在26公里的海岸线上，保育区的母牛-小牛对密度可高达3.2对/平方公里。虽然一个年轻的出生和哺乳专门为7个月至一年，最近的观察托儿所的理由包括3个事件，显然被遗弃/孤儿小牛的一年已被视为与至少2-3个不同的母牛小牛对在11-38天的时间。在其中2例病例中，观察到试图从这些雌性中分离，雌性的反应从极端回避到明显的耐受。在一个例子中，对同一个三人组的观察持续了21天，非后代似乎至少与后代进行了平等的竞争，尽管母亲将她的回避策略更多地指向非后代而不是自己的小牛。与此同时，与成年雌性的大小相比，两只小牛的长度都有所增长：它们随后的存活率未知。在单胎物种中，非后代的哺乳通常是罕见的，雌性的成本可能很高：对于露脊鲸等季节性喂养的神秘动物来说，哺乳的成本在母牛分娩后大约4个月恢复喂养之前无法收回。因此，这也许并不奇怪，这些是第一次记录观察到的同时哺乳尝试的后代和非后代小牛的任何mysticete。
During the austral winter, adult female southern right whales Eubalaena australis enter the South African coastal waters to give birth and raise their young. Most births take place over a 4-month period, when the females congregate in specific coastal areas or nursery grounds for up to a recorded maximum of 105 days. At this time, the density of cow—calf pairs in nursery areas can reach as high as 3.2 pairs/km2 over 26 km of coastline. Although a single young is born and suckled exclusively for 7 months to a year, recent observations on nursery grounds include 3 incidents where apparently abandoned/orphaned calves-of-the-year have been seen associating with a minimum of 2–3 different cow—calf pairs over periods of 11–38 days. Attempts to suckle from these females have been noted in 2 of the cases, with the response of the female varying from extreme avoidance to apparent tolerance. In one instance where the observations of the same trio extended over 21 days, the non-offspring appeared to compete at least equally with the offspring, even though the mother directed her evasive tactics more at the non-offspring than her own calf. At the same time, both of the calves exhibited some growth in length when compared with the size of the adult female: their subsequent survival is unknown. Non-offspring nursing in monotocous species is generally rare, and the costs to the female potentially high: this is certainly the case for seasonally feeding mysticetes such as the right whale, where the costs of lactation cannot be recovered until the cow resumes feeding about 4 months after parturition. Hence, it is perhaps not surprising that these are the first recorded observations of contemporaneous nursing attempts by offspring and non-offspring calves of any mysticete.