Elephants Better Beat the Heat--or Else

Elephants Better Beat the Heat--or Else
大象更好的抵抗酷暑——或许不是
When summer hits, I dread jogging outside. But a study finds that elephants can be in true danger in the heat.
当夏天来袭时，我害怕在外面散步。但是一项研究发现，大象在酷暑中会遭遇真正的危险。
As creatures get bigger, they have smaller surface-area-to-body-volume ratios. Fully grown Asian elephants thus pack a lot of mass into a body with a relatively small surface area. And surface area limits how much body heat you can dissipate.
由于躯体大，相对于体积，他们的体表面积更小。完全成熟的亚洲象可以以相对小的表面积背重量较大的物品。体表面积限制了身体可以散发的热量。
For the study, two female elephants in the Audubon Zoo in New Orleans walked around a half-mile track under various conditions. The outdoor temperature during these sessions ranged from a chilly 8 degrees Celsius to a scorching 35 degrees.
研究中，两只雌性大象在 Audubon Zoo in New Orleans在不同的条件下 ，走一个半英里的跑道。室外温度从8摄氏度到35摄氏度。
Clear, hot days were the worst. The already limited hide is now itself heated by the sun. With the equivalent of a busted radiator, the elephants retained 56 to 100 percent of their body heat internally. Which could make a mere four hours of exercise fatal. The research on elephant exertion is in the Journal of Experimental Biology. [M.F. Rowe et al., Heat storage in Asian elephants during submaximal exercise: behavioral regulation of thermoregulatory constraints on activity in endothermic gigantotherms]
Fortunately, elephants have ways to beat the heat: shift activity to after dark and, of course, go for a dip.
很明显，热天大象的表现最差。它们本来非常受限的皮肤现在太阳炙烤。相当于破坏的散热器，大象保留了56%的热量在体内。这会使得仅仅四个小时的活动变得致命。大象研究发表在 in the Journal of Experimental Biology. [M.F. Rowe et al., Heat storage in Asian elephants during submaximal exercise: behavioral regulation of thermoregulatory constraints on activity in endothermic gigantotherms]
幸运的是，大象有方法战胜酷热：把活动改到夜间，当然，需要一点光照。