Transport operators in northern Japan are sprinkling wolf urine near roads and broadcasting the roar of lions near train tracks in a bid to keep deer away and reduce accidents, officials said on Monday.

Nexco East, an expressway operator, imports wolf urine from the United States to spray on the highways it operates in Hokkaido, the northernmost of Japan's four main islands.

"Even though we have increased the height of fences to 2.5 metres (8.3 feet) from 1.5 metres, fences sometimes break because of heavy snow, so we need this stop-gap measure while mending them," a company official told AFP.

"The effect lasts about a month, but it won't be effective forever because deer get used to the smell," he said.

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.

There are now around 650,000 deer on the island, sometimes wreaking havoc with farmland and transport systems.

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.

He added there were 2,581 incidents involving deer last year, a figure that had doubled in less than a decade.