Discovered: Human relative detected in hunter-gatherer DNA; watching the imperial cormorant's deep-sea food dive; endangered whale song recorded; malaria vaccines don't bestow malaria immunity. 

Human "sister" species detected. By studying DNA samples extracted from 15 hunter-gatherer people living in Cameroon and Tanzania, a team of biologists was able to detect the genetic signature of a long-extinct species closely related to humans. This related species to the modern human most likely existed in isolation for a long time, but its DNA eventually joined the Homo sapiens gene pool through interbreeding. "There is a signal that demands explanation, and archaic admixture seems to be the most reasonable one at this point," says UC Santa Cruz genome biologist Richard "Ed" Green. More research will be needed to differentiate this mysterious species from Neanderthals and Denisovans.  [Science News]

Song of endangered whales recorded. Kate Stafford, an oceanographer at the University of Washington, recorded bowhead whale sounds for a full year off the frigid east coast of Greenland, yet when she listened back on the tapes was surprised to hear them singing constantly. There have been only about 40 sightings of the rare bowhead whales since the 1970s. Stafford didn't expect to pick up much audio from whales crossing through the harsh Fram Strait. "We hoped to record a few little grunts and moans," says Stafford, who has identified 60 discrete songs. "We were not expecting to get five months of straight singing." The discovery suggests that the critically endangered bowhead whale may be rebounding. [University of Washington]

"Superbird" descends to the ocean floor. Researchers with the Wildlife Conservation Society and the National Research Council of Argentina who have been studying a group of protected imperial cormorants in Patagonia recently had a great idea. They decided to strap a camera on one of the sea birds to better understand its feeding habits. With camera in tow, the mighty little bird dove 150 feet underwater in just 40 seconds. Once it reached the ocean floor, the cormorant rooted around for about 80 seconds until it caught a small fish, then resurfaced in another 40 seconds. This is the first time scientists have been able to witness the bird's feeding process first-hand. Watch a video of the cormorant's dive below. [Wildlife Conservation Society]

Malaria vaccines may do the exact opposite of what they're supposed to do. Malaria is one of the world's most pervasive and insidious infections, but the vaccines we to fight it with might only make matters worse. That's the conclusion Pennsylvania State University's Andrew Read and the University of Maryland's Chris Plowe have reached. In trials of the experimental malaria vaccine AMA-1,* malaria infections in mice evolved to overcome malaria immunity, and in doing so, became even more severe. This means that the vaccine is "leaky," which is how scientists describe vaccines that don't bestow air-tight immunity. [New Scientist]

*Correction: This story originally stated that the vaccine RTS,S was proven to be ineffective at preventing malaria.