Pandas have an excellent publicity machine. They're so cute! They're so lazy! They're so endangered! (So it's not all terrific, but at least they're getting attention.)
But one thing that Panda Corp. has hidden from you? The fact that Mama Panda is a coldhearted, favorite-choosing shrew of a parent. Or a little less dramatically: Mama Panda will often give birth to two babies but almost always only raises one [source: Angier].
While this may seem shockingly callous to baby-loving (not to mention panda-loving) humans, you have to remember that raising babies in the wild -- even super adorable, cuddly ones -- is not easy. Panda moms have to expend an enormous amount of energy to even digest their own food, and providing milk or resources for little ones is extremely difficult [source: Buchen]. By concentrating their energy on one of the babies, the chance of having one healthy offspring seems better than having two weak progeny.