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Horses remember if you smiled or frowned when they last saw you

Stop pulling faces!

Pal Teravagimov Photography / Getty

By Sam Wong

Why the long face? Horses can remember the facial expressions they see on human faces and respond differently if you smiled or frowned when they last saw you.
Leanne Proops, now at the University of Portsmouth, UK, and her colleagues at the University of Sussex showed in 2016 that horses respond differently to photographs of happy or angry human faces. Now they have studied whether horses can form lasting memories of people that depend on their facial expressions.
First, they showed horses a photo of one of two human models, displaying either a happy or angry face. Several hours later, the model visited the horse in person, this time with a neutral expression. As a control, some horses saw a different model in the second part to the one they saw in the photograph.
Crucially, the models didn’t know which photo the horse had seen earlier. In the early 20th century, a horse called Clever Hans amazed audiences by appearing to answer simple mathematical problems by tapping his hoof. It turned out he was responding to involuntary cues from his trainer. Proops’ study aimed to eliminate such cues.
The team found that the horses remembered the models’ previous facial expressions.

Did I see you earlier?

Universities of Sussex and Portsmouth

Look at me

Horses prefer to look at negative and threatening sights with their left eye, and positive social stimuli with their right eye. In the study, when they saw a model they had seen frowning earlier, they spent more time looking with their left eye. They also exhibited more stress-related behaviours, like scratching and floor sniffing. In contrast, when they saw a model they had seen smiling earlier, they spent more time looking with their right eye.
Many other animals have shown an ability to remember human faces, including sheep and fish. Wild crows will hold a grudge for years against people who have treated them badly, and even teach other crows to mob their enemies.
However, the horses seem to form an opinion about people based only on their expression in a photograph. “That’s something we haven’t really seen in animals before,” says Proops.
“The horse family has the most expressive faces after the primates, so logically they pay attention to faces and expressions,” says Frans de Waal at Emory University in Atlanta. “Horses surrounded by people have ample opportunity to learn what our expressions mean.”

Journal reference: Current Biology, DOI: 10.1016/j.cub.2018.03.035

https://www.newscientist.com/article/2167423-horses-remember-if-you-smiled-or-frowned-when-they-last-saw-you/

Rainforest romanticism is derailing our hunt for new drugs

The more pristine the forest, the more attractive it looks to conservationists. The reality is more complex, argues an eclectic new book, The Ethnobotany of Eden

Venom from giant centipedes can help treat neurological conditions

Michael D. Kern/Naturepl.com

By Adrian Barnett

IN MY taxi to the airport, the talk has turned to rainforests and whether cutting them down is bad. “Its not like here in the UK, where we know everything,” I say, waving at the soggy countryside. “I work in Brazil and we don’t know what’s in many forests. Cutting them down to grow soya can be a huge loss.”

That doesn’t impress the taxi driver, who left his country because of famine. I go on: “Then there’s all the medicinal plants in rainforests.
https://www.newscientist.com/article/mg23831830-900-rainforest-romanticism-is-derailing-our-hunt-for-new-drugs/

An entire Arctic ecosystem could vanish within the next decade

The Barents Sea, home to a diverse array of wildlife, could be completely gone in just a few years – perhaps the most dramatic impact of climate change yet seen

Waves crash along the coast of the Barents Sea

Franz Aberham/Getty

By Andy Coghlan

An entire Arctic ecosystem suddenly started shrinking within the last 10 years and could be gone within another decade. The collapse could be the largest, fastest impact of climate change seen to date.
“It could happen within the next few years, or within 10 or 20 years,” says lead author Sigrid Lind of the Institute of Marine Research in Tromsø, Norway. “We can’t say precisely.”
https://www.newscientist.com/article/2172444-an-entire-arctic-ecosystem-could-vanish-within-the-next-decade/