这只海豚妈妈收养了一个来自不同物种的婴儿

这只海豚妈妈收养了一个来自不同物种的婴儿

Bottlenose dolphin mothers typically raise one calf at a time, so researchers took notice when they saw a mother with two calves off the coast of Rangiroa Atoll in French Polynesia. Two calves aren't unheard of, but what really stood out was the difference between them. While one looked like a normal baby bottlenose dolphin, something was unusual about the other one.

宽吻海豚妈妈通常一次只喂养一头幼崽，所以当研究人员在法属波利尼西亚的兰吉罗阿环礁海岸看到一头母海豚和两只幼崽时，就注意到了这一点。两只牛犊并不是闻所未闻，但真正引人注目的是它们之间的差异。其中一只看起来像一只正常的宽吻海豚宝宝，而另一只却有些不同寻常。

Unlike a bottlenose dolphin's namesake snout, this calf had a blunter, rounder face. Led by Pamela Carzon of the Groupe d’Étude des Mammifères Marins (GEMM) de Polynésie, the researchers eventually realized the calf wasn't a bottlenose dolphin, but a baby melon-headed whale, as they report in the journal Ethology. That's not only a different species of dolphin, but a different genus.

与宽吻海豚不同，这只海豚的脸更粗更圆。在波利尼西哺乳动物研究小组的帕梅拉·卡松的带领下，研究人员最终意识到，这头小海豚不是宽吻海豚，而是一头瓜头小鲸鱼，他们在《动物行为学》杂志上发表了研究报告。这不仅是不同种类的海豚，而且是一个不同的属。

Photo: Pamela Carzon/Groupe d’Étude des Mammifères Marins

As Erica Tennenhouse reports for National Geographic, this is the first known case of a wild bottlenose mother adopting a calf of another species. And it may be just the second confirmed case of any wild mammal adopting a baby from outside its own genus. (Aside from humans, of course, who commonly adopt dogs, cats and other nonhuman mammals as pets.)

据艾丽卡·坦南豪斯为《国家地理》杂志报道，这是已知的第一例野生宽吻海豚妈妈收养另一物种幼崽的案例。这可能是第二例被证实的野生哺乳动物收养自己属以外的婴儿的案例。(当然，除了人类。人类通常会收养狗、猫和其他非人类哺乳动物作为宠物。)

Wild mammals sometimes adopt unrelated babies from within their own species, but interspecies adoption is much less common, and cross-genus adoption is even rarer. Until now, the only scientifically documented case was from 2006, Tennenhouse notes, when a group of capuchin monkeys were reported to be raising a baby marmoset.

野生哺乳动物有时会从它们自己的物种中收养不相关的婴儿，但跨物种收养就不那么常见了，跨属收养就更少了。Tennenhouse指出，到目前为止，唯一有科学记载的案例发生在2006年，当时有报道称一群卷尾猴正在抚养一只小狨猴。

This photo shows the bottlenose mom with her biological daughter (left) and adopted son (top), a melon-headed whale. (Photo: Pamela Carzon/Groupe d’Étude des Mammifères Marins)

In this new case, the bottlenose mom already had a young calf — presumably her biological daughter — when she took in the melon-headed whale. That's an extra burden for a species that usually raises one calf at a time, although the researchers think the first calf might have actually made the mother more open to adopting the second.

在这个新案例中，宽吻海豚妈妈在收养这头瓜头鲸时，已经有了一只幼崽——可能是她的亲生女儿。对于一个通常一次只养一个幼崽的物种来说，这是一个额外的负担，尽管研究人员认为，第一头“小牛”实际上可能会让母亲更愿意收养第二头“小牛”。

Carzon and her colleagues have been conducting a long-term study of this bottlenose community since 2009. The melon-headed calf first showed up in 2014, when he was about a month old, and quickly grew inseparable from his new mother. Her own daughter had been born the same year, and the trio became a common sight as they swam around the area together. (There was a little sibling rivalry, though, as the adopted calf jockeyed with his sister for a swimming position underneath their mother.)

Carzon和她的同事从2009年开始就对宽吻海豚进行了长期的研究。这头瓜头小鲸鱼首次出现在2014年，当时它大约一个月大，很快就和它的新妈妈形影不离了。它自己的女儿也是在同一年出生的，当它们一起在这片海域游泳时，这三个人就成了一道常见的风景。(不过，当这只被收养的小鲸鱼和妹妹争夺妈妈身下的游泳位置时，它们之间有了一场小小的兄弟姐妹间的竞争。)

This family of three lived together for about a year and a half, until the biological daughter disappeared for unknown reasons. It's possible something bad happened to her, although as Meilan Solly notes in Smithsonian Magazine, she might have just moved on to a different social subgroup. The adopted son, however, remained with his mother until April 2018. That's nearly three years after she adopted him, and it's around the age when many bottlenose dolphin calves wean.

这个三口之家在一起生活了大约一年半，直到亲生女儿不知何故失踪。也许它发生了什么不好的事情，尽管正如美兰·索利在《史密森杂志》上所指出的，它可能只是换了一个不同的社会亚群体。然而，这个养子直到2018年4月才离开母亲。那是在它收养它将近三年之后，也就是许多宽吻海豚幼崽断奶的时候。