A video of a wild elephant in India blowing out ashes has baffled wildlife experts around the world.
Vinay Kumar, a scientist belonging to the Wildlife Conservation Society (India), filmed the 48-second video during a work trip to Nagarhole forest in Karnataka state in April 2016.
He told the BBC that he had not released the video until now because he did not "quite realise its importance".
Scientists say they are still not clear why the elephant was blowing ashes.
"This is the first known video-documentation of a wild elephant exhibiting such behaviour, and this has scientists had experts puzzled," a statement issued by Wildlife Conservation Society (India) said.
Mr Kumar said he and his team were visiting the forest early in the morning to monitor camera traps set up to capture images of tigers. He spotted the female elephant barely 50m (164ft) away and began filming with his point-and-shoot camera.
The elephant "appears to ingest charcoal" left by a controlled fire on the ground and "blow out the ashes", according to the statement.
"What we saw that day almost appeared as though the elephant was smoking - she would draw up a trunk full of ash close to her mouth and blow it out in a puff of smoke!" Mr Kumar said.
Elephant biologist Varun R Goswami, who has examined the video, believes that "most probably, the elephant was trying to ingest wood charcoal, as she appeared to be picking up something from the burnt forest floor, blowing away the ash that came along with it in her trunk, and consuming the rest".
"Charcoal has well recognised toxin-binding properties, and although it may not not have much nutritional content, wild animals may be attracted to it for this medicinal value," he said.
"Charcoal can also serve as a laxative, thereby doubling its utility for animals that consume it after forest fires, lighting strikes, or controlled burns.".