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18 | NewScientist | 5 April 2014 IS THE person in front of you sadly fearful or fearfully angry? Look closely, you should be able to tell from their face. External expressions of our feelings have focused on six universally recognised emotions: anger, fear, sadness, joy, disgust and surprise. The facial muscles and movements we all use to pull these faces are well documented. But our emotional lives are much more complex than this. A team led by Aleix Martinez of Ohio State University in Columbus has identified and categorised the facial muscles used to express compound emotions – those made up of pairings of the basic six. The team studied 230 people’s faces as they reacted to emotion-provoking scenarios, and mapped the activated muscles. He found 15 compound emotions everyone expressed using the same facial muscles. These were distinct enough from each other, and from the basic six, to be recognised as separate by both humans and a computer model (PNAS, DOI: 10.1073/ pnas.1322355111). The work could lead to more perceptive computer vision algorithms, especially if it was broadened out to include emotions such as frustration. JACK LEVY/NATIONAL GEOGRAPHIC CREATIVE Sneaky sex in the city fails to turn these owls’ heads VARIETY isn’t the spice of life for urbanite burrowing owls, it seems. The owls of Argentina have embraced town life, nesting in large numbers in abandoned mammal burrows in urban areas. While the nests of their rural cousins can be separated by as much as 15 kilometres, urban nests can be as little as 10 metres apart. Birds of other species are more likely to cheat on their partner when population density increases, so Martina Carrete of the Doñana Biological Station in Seville, Spain, wondered if the same is true for burrowing owls (Athene cunicularia) in and around Bahía Blanca, Argentina. Her team took blood samples from a total of 1100 urban owls, both chicks and adults, from 61 urban and seven rural nests over six breeding seasons. Genetic analyses showed that all rural chicks were the offspring of the two adults looking after their nest. It was the same story in urban settings too, despite the urban owls’ greater opportunity to stray. Only in one case were the city chicks not related to the adult male looking after them. Either female owls only have eyes for their partners, or male owls watch their partners very carefully, the researchers conclude (PLoS One, doi.org/r4r). “The need for paternal care might constrain both partners to remain faithful even if [population] densities change,” says Dieter Lukas at the University of Cambridge. Face map recognises complex emotions Dino extinction benefited reef fish FROM crisis comes opportunity. The asteroid-triggered mass extinction that wiped out the dinosaurs 65 million years ago may have helped create today’s reef fish communities. Samantha Price at the University of California, Davis, and her colleagues looked at a group of reef fish called acanthomorphs. Using DNA data, they were able to pinpoint when different kinds of acanthomorph moved onto reefs. They found two peaks of reef colonisation: one began 25 million years before the extinction, and one right after, creating today’s marine biodiversity hotspots (Proceedings of the Royal Society B, DOI: 10.1098/rspb.2014.0321). Acanthomorphs may have outcompeted the fish that were there before the extinction. Or the event may have killed reefs built from mollusc shells, triggering the rise of coral reefs and enabling the second pulse of colonisation. Eau de swine silences noisy dogs POSTMEN will be pleased. They can now calm unruly dogs with a small dose of a pig pheromone. Androstenone is found in boar saliva and helps attract mates. Now it is an ingredient in a spray for use on boisterous dogs. John McGlone of Texas Tech University discovered the effect by luck. “My dog was barking,” he says. “I sprayed it and he stopped.” McGlone then tested the pheromone by spraying dogs while exposing them to a loud noise that would normally excite them. It proved better than an alcohol spray at keeping the dogs calm (The Professional Animal Scientist, vol 30, p 105). The spray is now a commercial product, but McGlone says he still doesn’t know exactly how it works. in Brief
