Wolf urine and lion roars are being used by transport bosses in northern Japan to tackle the growing problem of collisions caused by deer.

The number of accidents caused by the animal has more than doubled in Hokkaido – the northernmost of Japan’s four main islands – in the past ten years.

As a result, transport officials have taken drastic action. As well as spraying wolf urine near roads and railways they will also be broadcasting the roar of lions to try to keep the deer away.

The urine is being imported from the United States to spray on the island’s highways.

The deer population in Hokkaido was nearly wiped out in the early 20th century because of overhunting and sometimes brutal winters.

But conservation efforts – and the extinction of the indigenous wild wolf population – led to their recovery.

Hokkaido Railway Co earlier this year erected equipment that broadcasts the roar of lions in an effort to keep the timid animals away from its tracks, a spokesman said.