Australian zoo sniffs out way to lift elephant's mood
We're often reminded that elephants have a remarkable memory, but fewer people realise they possess a powerful sense of smell.
A recent study showed African elephants have the most genes dedicated to smell of any mammal.
The US military has also trained elephants to sniff out explosives in the South African countryside.
Now an Australian zoo is harnessing an elephant's smell for a more modest aim - improving his mood.
Hide and seek
Putra Mas, Perth Zoo's only male Asian elephant, has been trained to find particular scents hidden around his enclosure.
The idea came after zookeepers noticed signs of boredom, which can affect the behaviourally complex animals in captivity.
Unlike the zoo's two female elephants, Putra Mas's temperament prevented him from being walked around the grounds.
So keepers tried to "brighten his day", said Peter Mawson, the zoo's director of animal health and research.
Putra Mas was taught to identify scents including lemongrass, coffee, fur, feathers and animal urine. He would squeak with each discovery.
Mr Mawson said the programme had been very successful.
"It's made a noticeable difference in the level of trust between our bull elephant and his keeping staff," he told the BBC.
"And he certainly seems to enjoy the game. He has high expectations when he sees the setup being put in place to play the game."
Taking it further
Mr Mawson said the zoo had now extended the programme to the female elephants.
"It may even be applicable to some of the other animals in the zoo, who may not be as intelligent as our elephants, and are maybe a little more difficult to work with," he said.
"Our big cats, sun bear, hyena and probably the painted dogs - all for whom a sense of smell is really important."
Reporting by the BBC's Greg Dunlop