Even at this tender age, Kintana brandishes outlandish adaptations for survival in lemurs' only native home, the African island of Madagascar. In the forest the aye-aye's batlike ears can detect insect larvae squirming inside trees. A bark-breaking bite from tough incisors and a subsequent probe with a long, bony second digit seals the meal.

That adaptation is more curse than blessing for some of these tree dwellers, which are beaten by Madagascan villagers who see the crooked claw as a harbinger of death. Farmers too get their licks, persecuting the world's largest nocturnal primates for their night raids on sweet crops like coconuts and sugarcane. Also, some Madagascans hunt the 4.5-pound (2-kilogram) aye-ayes for their meat.

But the aye-aye's greatest threat is deforestation, which is largely responsible for its listing as endangered on the World Conservation Union's Red List of Threatened Species—and which may one day make captive births crucial to the species's survival.

—Ted Chamberlain

A newborn giant panda is about as big as a stick of butter and lacks the familiar black-and-white markings for its first month or so of life. Successful births in captivity are extremely rare—and extremely prized by conservationists, given the species's dwindling numbers. About 1,600 giant pandas remain in the wild, plus about 160 living in zoos and breeding centers, according to the National Zoo.

Adding a circle-of-life pallor to the otherwise rosy news, China this week announced that the world's oldest known giant panda, a female named Mei Mei, had died at a zoo in the city of Guilin at age 36—or about 108 in human years.

—Ted Chamberlain