科学美国人60秒 SSS 郊狼的饮食涵盖水果和家猫（在线收听）

This is Scientific American's 60-second Science. I'm Jason Goldman.

这里是科学美国人——60秒科学。我是杰森·古德曼。

Coyotes can do really well in some cities. Los Angeles has always had coyotes, while the predators are relative newcomers to places like Chicago and New York. But how much do coyotes rely on human activity for food?

郊狼在一些城市可以过得很好。洛杉矶一直都有郊狼，而芝加哥和纽约等地，它们刚到没多长时间。但郊狼依赖人类活动来获取食物的程度有多大？

"Los Angeles is this really interesting, unique city. Coyotes occur literally across the gradient. They're everywhere from downtown Los Angeles, at the stadium where the Dodgers play, all the way into the Santa Monica Mountains, in some of the more rural, rugged landscapes."

“洛杉矶是个非常有趣而且很独特的城市。郊狼可以说是跨梯度出现的。从洛杉矶市中心到道奇队比赛的体育场，一直到圣莫尼卡山某些更田园、崎岖的景观，它们几乎无处不在。”

Biologist Rachel Larson, who led a newly published study on coyotes in the L.A. area. Now at the University of Iowa, she did this work as a graduate student at California State University in Northridge.

生物学家雷切尔·拉森说到，她领导了一项新发表的有关洛杉矶地区郊狼的研究。她是加州州立大学北岭分校的研究生，她在爱荷华州大学进行了这项研究。

She and her team used two different methods to figure out what coyotes were eating. First, they worked with citizen scientists to collect and analyze evidence the animals left behind.

她和团队用两种不同方法确定了郊狼的食物。首先，他们与公民科学家合作，收集和分析郊狼遗留的证据。

"Scat tells you what a coyote had for its most recent meal. But scat has really detailed information. When you look at the hair and the teeth and seeds and bones, you can pretty much identify almost the exact species that those coyotes were eating. But it's only one meal."

“粪便会告诉你郊狼最近一顿吃了什么。粪便包含非常详细的信息。观察粪便中的毛发、牙齿、种子和骨头，就能相当准确地判断出郊狼刚刚吃的是什么物种。但这只是一顿饭的食物。”

So the researchers also measured the proportions of different carbon and nitrogen isotopes in whiskers from coyotes.

因此，研究人员还测量了郊狼胡须中不同碳同位素和氮同位素的比例。

"The isotopes tell you the general diet over a much broader time span. For the whiskers, we think it's approximately several weeks' to even a few months' worth of diet. It actually tells you what the coyote is digesting and assimilating into its own tissues."

“同位素可以告诉我们，在更广泛的时间跨度内的一般饮食。对于胡须，我们认为它能说明大约几个星期甚至几个月内的饮食。它确实能告诉你郊狼正在消化和吸收到自身组织中的东西。”

Rural coyotes stuck almost exclusively to natural food resources. In the most heavily urbanized areas, they relied on foods humans made it possible for them to get. That includes people's cats, which showed up in around 20 percent of their droppings.

乡村郊狼几乎完全依赖天然食物资源。而在城市化最深的地区，它们依赖人类提供的食物。其中包括家猫，约20%的郊狼粪便中有家猫的成分。

And in suburbs, coyotes ate everything. During the winter, they hunted rabbits, gophers and squirrels. But in the drier summer months, they relied more on human foods, especially on fruits fallen from backyard plants like figs, palms and grapes. The findings are in the journal PLOS ONE.

在郊区，郊狼什么都吃。冬天，它们捕食兔子、囊地鼠和松鼠。但在更干燥的夏季，它们更依赖人类食物，尤其是无花果、棕榈和葡萄等后院植物掉落的水果。研究结果发表在《公共科学图书馆·综合》期刊上。

"One of the things that our study has found is how important things like fruits are to animals like coyotes. They're not strictly carnivorous. They'll basically eat anything that fits in their mouth."

“我们的一项研究发现了水果对郊狼等动物来说有多重要。郊狼不是严格意义上的食肉动物。基本上只要是进嘴里的东西，它们都会吃。”

By understanding these patterns, wildlife officials can better help homeowners learn to coexist with coyotes—and to keep their pets safe.

通过了解这些模式，野生动物官员可以更好地帮助房主学会与郊狼共存，并保护他们宠物的安全。

"So now we have more information about the kinds of things that are attracting the coyotes to certain areas. They love having cats around, and they love having garbage and fruits around. So if we can control their access to those things, you'll no longer see coyotes utilizing that space. There's nothing attracting them there."

“因此，我们现在掌握了更多信息，更加了解哪些东西能吸引郊狼到特定地区。它们喜欢猫、垃圾和水果在周围。所以，如果我们能控制郊狼，不让它们接近这些东西，你就不会再看到郊狼利用那个空间了。因为那里没有什么吸引它们的东西。”

Thanks for listening for Scientific American's 60-second Science. I'm Jason Goldman.

谢谢大家收听科学美国人——60秒科学。我是杰森·古德曼。