SSS 2011-06-15

（单词翻译）

This is Scientific American’s 60-Second Science. I’m Cynthia Graber. This will just take a minute.

Climate change affects seasonal¹ events—spring flowers open earlier, songbirds breed sooner. But what about mammals? A new study documents the effect on a special breed of cows in the U.K.

Northumberland’s Chillingham cattle were once domesticated², but now roam free. And they offer a unique opportunity for study, because owners started keeping detailed³ records on them in 1860, due in part to the urging of none other than Charles Darwin. The cattle are thus an excellent source of long-term info on how earlier springs affect what’s called phenology—seasonal lifecycle events.

The Chillinghams can give birth all year, not just spring and summer like most U.K. mammals. And the data show that over the past few decades, there’s been an increase in winter births, which the researchers correlated to warmer springs the previous year: plants grow earlier, the cattle have more access to nutrition and they conceive earlier.

But winter babies are more likely to die before they turn one. The research was published in the Journal of Animal Ecology.

The researchers say that even mammals that breed year round—which should offer protection against seasonal shifts—may still feel the impact of climate change.

Thanks for the minute. For Scientific American’s 60-Second Science, I’m Cynthia Graber.