Cosmos
Cosmos is a quarterly science magazine. We aim to inspire curiosity in ‘The Science of Everything’ and make the world of science accessible to everyone.
By Cosmos
Drones can be used to spy on birds
Oh, to have the eyes of an eagle. As drones become cheaper to build and buy, bird researchers might at last be able to peer into nests in remote places such as mountain tops or marshes and record the secret lives of birds. That is, as long as the drones do not disturb the birds.
David Grémillet and his colleagues at the French research organisation CNRS put the drones to the test. They repeatedly flew a drone as close as four metres away from mallards, flamingos and greenshanks – the latter two species are known to be easily spooked. All good: the birds were largely unperturbed regardless of the drone’s colour or speed. Alas, when the drone approached eagle-like from directly overhead, the birds (not-surprisingly) reacted. The study suggests researchers will have to fly stealthily if they want to observe some behaviours, but bodes well for carrying out census work in remote regions. – James Mitchell Crow
Chewing gum is good for you
The ancient Greeks knew chewing gum was good for their teeth. They chomped on mastiche, a tree sap – a practice that continues to this day. But dentists prefer us to chew sugar-free gum. Their scientific explanation is that it works by neutralising lactic acid produced by bacteria after a sugary meal – but there may be more to it. A study published in PLoS ONE shows the gum itself can trap decay-causing bacteria.
Researchers from the University of Groningen in The Netherlands and the Wrigley chewing gum company had five volunteers chew gum for between 30 seconds and 10 minutes then spit the gum into sterile water. The “chewed in” bacteria were then counted on each piece.
They found that while 30 seconds was enough to haul in the biggest catch – up to 100,000,000 bacteria – chewing for 10 minutes brought in a greater diversity of bugs which also helps protect against decay.
