Human beings aren’t the only animals to yawn when they see another of their kind doing the same. So do dogs and some primates, including chimpanzees. But in a new study at Yerkes National Primate Research Center in Atlanta, chimps appear to make an intriguing distinction: they were more likely to yawn in response to a member of their immediate group than to strangers. Researchers say “contagious yawning” is a sign of empathy. Parents say covering your yawn is a sign of good manners.
How Humpback Songs Go Platinum
Male humpback whales in the South Pacific all sing the same song—until another one catches on and they start singing a new tune. An 11-year study showed that songs usually originate off Australia and spread east. How? A few whales may move east and take the songs with them, or they may swap songs along shared migration routes.
Leaps and Bounds
Life: Is born in a stream or lake, then swims to and roams the ocean.
Death: Returns to fresh water to spawn and die.
After Life: Salmon have long been recognized as a major food source for animals and aquatic plants in the fish’s spawning grounds. But researchers at Simon Fraser University have found that nutrients from dead fish influence the number and types of plants that grow more than 100 feet into the forest. The researchers say conservation plans should take into account not only the number of fish needed for a strong population at sea, but also the number that die inland.