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To owls, the distress call of the greater mouse-eared bat sounds similar to hornets buzzing.Credit: F. Deschandol and P. Sabine/Biosphoto/Minden Pictures
Bats buzz like hornets to scare off owls
Some bats can imitate the sound of buzzing hornets to scare off owls — the first documented case of a mammal mimicking an insect to deter predators. Researchers compared the sound structure of buzzing by the European hornet (Vespa crabro) to that of the distress call of greater mouse-eared bats (Myotis myotis). At most frequencies, the two sounds were not dramatically similar, but they were when the bat’s call was stripped down to include only frequencies that owls can hear. “It makes total sense to me that bats, with their remarkable vocal abilities, would resort to acoustic means to fool predators,” says animal-behaviour ecologist Mirjam Knörnschild.
Largest ‘marsquake’ ever detected
NASA’s InSight Mars lander has recorded the most powerful tremor ever observed on another planet: a magnitude 5 quake. This wouldn’t be a record-breaker on Earth but is close to the upper limit of what scientists expected to see on Mars. “Since we set our seismometer down in December 2018, we’ve been waiting for ‘the big one’,” says InSight principal investigator Bruce Banerdt. “Scientists will be analysing this data to learn new things about Mars for years to come.”
Big ships are killing huge sharks
Tracking data from endangered whale sharks (Rhincodon typus) suggest that the endangered gentle giants are being killed by large vessels. Researchers tracked the movements of large vessels, such as tankers and cargo ships, and a total of 348 whale sharks for seven years. Each month, more than 90% on average of vessel traffic worldwide overlapped with areas used by sharks. And sharks whose tracking tags showed that they were sinking — and were therefore likely to be dead — tended to be on busy shipping routes. “As a first step to address this crisis, the International Maritime Organization (IMO) could develop a global reporting scheme” for collisions, say the scientists.
Nature Research Highlight | 2 min read (Nature paywall) & The Conversation | 5 min read
Reference: Proceedings of the National Academy of Sciences paper
Features & opinion
Why menopause matters in academia
Most workplaces don’t see menopause — and the mental and physical changes that accompany it — as a condition they have to support. And many people going through menopause are reluctant to speak out, for fear it might undermine their careers. “You are in a predominantly male career. Who are you going to talk to? You kind of suffer in silence,” says electrical and computer engineer Carlotta Berry, who now counsels younger colleagues experiencing it. Jo Brewis, a management- and organization-studies researcher who has written menopause guidelines for UK higher-education institutions, says the most important thing is to raise awareness of its true nature. “Menopause is still quite widely misunderstood,” she says. “There’s this assumption that suddenly you are a flushing, incapable mess.”
Reference: Athena Swan guidance on menopause awareness in higher education
Sort out your units of measurement
An infamous mix-up between metric and imperial units caused the destruction of NASA’s Mars Climate Orbiter in 1999. And measurement mayhem is still happening, write members of two international metrology task forces. “Unless we take steps to ensure that measurement units are routinely documented for easy, unambiguous exchange of data, information will be unusable or, worse, be misinterpreted,” they argue. They call for:
• Scientists to pay attention to their units and to demand that their tools do, too.
• Developers to use the right digital representation systems for units.
• Funders to support systems for easy, unambiguous exchange of information.
• The entire scientific community to agree on a model to represent quantities and units.
The search for Alexander Grothendieck
Alexander Grothendieck was a revered mathematician, who uncovered connections between realms that seemed unrelated. His contributions transformed the field, says mathematician Michael Artin. “He came, and it was like night and day. It was a revolution.” But Grothendieck was an idiosyncratic and sometimes difficult person, who chose to be stateless and started a commune. When he was 42 years old, he abruptly left mathematics. In 1992, two mathematicians — Leila Schneps and Pierre Lochack — went searching for him. They found him, living as a hermit, at times subsisting only on dandelion soup.
Infographic of the week

Source: Caitlin Myers/Middlebury College
This map shows the potential repercussions if the verdict of the 1973 case Roe v. Wade is overturned in the United States. A leaked draft opinion suggests that the US Supreme Court might be about to end the precedent set by the landmark decision that ensured access to abortion. A Nature editorial argues that such a decision would fly in the face of an overwhelming body of evidence from economists and reproductive- and public-health researchers about the dire and unequal impact this ruling would have. (Nature | 6 min read)
See more of the week’s key infographics, selected by Nature’s news and art teams.