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科学美国人60秒: 奇鸟迁徙两次以繁殖后代

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Odd Bird Migrates Twice to Breed

奇鸟迁徙两次以繁殖后代

Most migratory birds spend their winters in one habitat, and then fly to a new area in the springtime to breed. They’ll raise one or more broods of young there. Then, come fall, they begin the trip back to their wintering grounds. But a new study suggests the phainopepla, a jet-black bird with a body type like a small cardinal, may have a different strategy.

大多数候鸟在一个栖息地过冬,然后在春天飞到一个新的地方繁殖。它们会在那里养育一窝或多窝幼鸟。然后,秋天来临时,他们开始返回过冬的地方。但一项新的研究表明,体型像小型红衣主教的喷黑鸟phainopepla可能有不同的策略。

“They might be itinerant breeders.So they breed once in one area, then they migrate, they go somewhere else and they breed a second time in that new area.”State University of New York, Oswego evolutionary biologist Daniel Baldassarre.For the phainopepla, that means nesting in the desert southwest during the springtime, before flying to the oak woodlands of the California coast for the summer.

“他们可能是流动的饲养员。所以它们在一个地方繁殖一次,然后迁移到另一个地方,在新的地方繁殖第二次。纽约州立大学进化生物学家Daniel Baldassarre说。对phainopepla来说,这意味着春天在西南沙漠筑巢,然后飞往加利福尼亚海岸的橡树林地避暑。

Baldassarre says birdwatchers have long suspected that phainopeplas are itinerant breeders. One hint that the same birds might be breeding in two different habitats was their vocal behavior. The pointy-headed songbirds are talented mimics, often copying the vocalizations of other bird species.

(Clip: female vocal mimic)

巴尔达萨尔说,鸟类观察者一直怀疑菲诺帕拉斯是流动的繁殖者。有一个迹象表明,同样的鸟可能在两个不同的栖息地繁殖,那就是它们的发声行为。尖头的鸣鸟是天才的模仿者,经常模仿其他鸟类的叫声。

“If you look at desert birds, they actually can mimic some species that you don't find in the desert, bird species that you would only find out in these woodland habitats.”And the reverse is also true—phainopeplas in woodland habitats will mimic species that are only found in the desert.

“如果你观察沙漠鸟类,你会发现它们实际上可以模仿一些你在沙漠中找不到的物种,一些你只能在这些林地栖息地找到的鸟类。“反过来也是正确的——林地里的棕叶藻会模仿只有在沙漠里才能找到的物种。

But to confirm that individual phainopeplas really do spend the breeding season in two different places, Baldassarre and his team outfitted the birds with tiny GPS transmitters and tracked their movements.“They all left those desert breeding habitats, migrated out to these coastal woodland habitats and stayed in a small kind of territory for basically the duration of summer when we know that phainopeplas are breeding in these woodland areas.”The researchers also found that both populations were very similar genetically, suggesting that they’re all members of the same gene pool.

但是为了确认每个菲诺帕拉斯雀确实在两个不同的地方度过了繁殖季节,巴尔达萨雷和他的团队给这些雀配备了微型GPS发射器并跟踪它们的活动。“它们都离开了这些沙漠栖息地,迁移到这些沿海林地栖息地,并在一小块领土上呆了基本上整个夏天,因为我们知道phainopeplas在这些林地繁殖。研究人员还发现,这两个群体在基因上非常相似,这表明他们都属于同一个基因库。

The study appears in the journal The Auk. (Daniel T. Baldassarre, et al., GPS tracking and population genomics suggest itinerant breeding across drastically different habitats in the Phainopepla)Baldassarre says itinerant breeding has only been documented in two other bird species to date and is most likely an adaptation to unpredictable sources of food.

这项研究发表在《The Auk》杂志上。(Daniel T. Baldassarre等人,GPS跟踪和种群基因组学研究表明,在大不相同的栖息地进行巡回繁殖)Baldassarre说,迄今为止,只有另外两种鸟类记录了这种巡回繁殖,很可能是为了适应不可预测的食物来源。

“That food supply disappears and so the birds literally have to physically move to follow the food.”

Such behavioral flexibility seems to be unusual, Baldassarre notes. Phainopeplas could thus be especially resilient in the face of climate change—a challenge other species may not be able to meet.

“食物供应消失了,所以这些鸟不得不跟着食物移动。”巴尔达萨尔指出,这种行为上的灵活性似乎不同寻常。因此,Phainopeplas在面对气候变化时可能特别有弹性——这是其他物种无法应对的挑战。Odd Bird Migrates Twice to Breed

Most migratory birds spend their winters in one habitat, and then fly to a new area in the springtime to breed. They’ll raise one or more broods of young there. Then, come fall, they begin the trip back to their wintering grounds. But a new study suggests the phainopepla, a jet-black bird with a body type like a small cardinal, may have a different strategy.

“They might be itinerant breeders.So they breed once in one area, then they migrate, they go somewhere else and they breed a second time in that new area.”State University of New York, Oswego evolutionary biologist Daniel Baldassarre.For the phainopepla, that means nesting in the desert southwest during the springtime, before flying to the oak woodlands of the California coast for the summer.

Baldassarre says birdwatchers have long suspected that phainopeplas are itinerant breeders. One hint that the same birds might be breeding in two different habitats was their vocal behavior. The pointy-headed songbirds are talented mimics, often copying the vocalizations of other bird species.

“If you look at desert birds, they actually can mimic some species that you don't find in the desert, bird species that you would only find out in these woodland habitats.”And the reverse is also true—phainopeplas in woodland habitats will mimic species that are only found in the desert.

But to confirm that individual phainopeplas really do spend the breeding season in two different places, Baldassarre and his team outfitted the birds with tiny GPS transmitters and tracked their movements.“They all left those desert breeding habitats, migrated out to these coastal woodland habitats and stayed in a small kind of territory for basically the duration of summer when we know that phainopeplas are breeding in these woodland areas.”The researchers also found that both populations were very similar genetically, suggesting that they’re all members of the same gene pool.

The study appears in the journal The Auk. (Daniel T. Baldassarre, et al., GPS tracking and population genomics suggest itinerant breeding across drastically different habitats in the Phainopepla)Baldassarre says itinerant breeding has only been documented in two other bird species to date and is most likely an adaptation to unpredictable sources of food.

“That food supply disappears and so the birds literally have to physically move to follow the food.”

Such behavioral flexibility seems to be unusual, Baldassarre notes. Phainopeplas could thus be especially resilient in the face of climate change—a challenge other species may not be able to meet.


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