MONARCHS IN WINTER Declines in the numbers of monarch butterflies crowding into winter refuges in Mexico (shown) raise the question of what’s going on the rest of the year. ~~ Pablo Leautaud/Flickr (CC BY-NC 2.0)
Genetic switch offers clue to why grasses are survival masters
Scientists have identified a genetic switch that helps grasses regulate their carbon dioxide intake.
One bold, misinformed spider slows a colony’s ability to learn
When this image was taken in 2003, the reindeer population on Russia’s Taimyr Peninsula numbered more than 800,000, down from 1 million animals in 2000. Now, there are only 600,000 reindeer, scientists say. ~~ Leonid Kolpashchikov
TIPPING POINT A new record of the Antarctic ice sheet’s formation suggests that carbon dioxide levels in the atmosphere could soon reach a tipping point that will make the ice sheet more vulnerable to melting. That includes ice in East Antarctica, such as Matusevich Glacier (shown). ~~ NASA Goddard Space Flight Center