Discovered: Humans know how dogs are feeling; health professionals are abusing propofol; massive bird nests function as socialist societies; male lions ambush their prey.

Humans know how dogs are feeling. That dogs make good pets because (in part) their faces convey emotion so well is no secret, but two scientists at Walden University discovered a scientific basis for our emotional relationship with dogs. "Volunteers could correctly spot when a dog was happy, sad, angry, surprised or scared, when shown only a picture of the animal’s face, suggesting that humans are naturally attuned to detecting how animals are feeling," according to The Telegraph. Even more surprising: individuals less experienced with dogs were more able to detect their emotional state. "People with minimal experience of dogs were better at identifying canine disgust and anger, perhaps because dog owners convinced themselves that their dog was not aggressive and so the associated facial expression was just playing." [The Telegraph]

Health professionals are abusing propofol. New research shows that health professionals are increasingly abusing propofol, a widely-used anesthetic, because they often have easy access to large quantities of it. Professionals who were studied "generally started using propofol to get to sleep," a pair of Georgia doctors discovered. "However, they quickly developed characteristics of addiction, with propofol becoming a preferred drug of abuse." Part of the uptick can be attributed to how quickly propofol abuse can turn a person's life upside-down: "About half of propofol abusers entered addiction treatment after dramatic events such as car crashes or other injuries." [Journal of Addiction Medicine]

Massive bird nests function as socialist societies. Sociable weavers, an African bird species, build nests so complex that the web of relationships formed resembles a socialist society: "Multiple families live together and even help raise each other's young," writes New Scientist. "You could call them socialist weavers, though that might bring to mind a collective of 19th-century Lancashire textile workers." That's not far off. The birds have to work together because of the relatively harsh African climate in which they live and breed. "Food is not super-abundant in the desert, so the birds, pictured below, delay breeding until they are 2 years old. It's one of the reasons that it makes evolutionary sense to live communally." [New Scientist]

Male lions ambush their prey. Male lions get a bad — and apparently undeserved — rap for lacking in the hunting department. But fresh research performed by two Carnegie Mellon scientists indicates that male lions do in fact know how to hunt down and violently kill their prey. "Scientific results show that ambushing prey from behind vegetation is linked to hunting success among male lions, despite lacking the cooperative strategies employed by female lions in open grassy savannas." The scientists found that other researchers had been tricked, somewhat, by the fact that male lions hunt in thick vegetation, where scientists are hesitant to survey. [Animal Behavior]

Image by Mila Atkovska via Shutterstock.