In Quebec, Alaska and Sweden, fencing "has been effectively keeping moose off the highway and has been effective in reducing moose-vehicle collisions," Tony Clevenger told provincial Supreme Court.
Research on the success of moose fencing has been around for more than 10 years yet the province has instead relied on public awareness campaigns, roadside brush cutting and highway signs, he said.
Clevenger said he could find no evidence that the province tracked how well those measures worked.
"It's extremely important that there be monitoring and research around these mitigation efforts to make proper decisions in future," he told Judge Robert Stack.
Clevenger, a Montana State University wildlife ecologist based in Alberta, specializes in how to prevent vehicle collisions with animals. For example, he cited 60 kilometres of highway fencing between Quebec City and Saguenay, and 365 kilometres installed in New Brunswick, along with underpasses for moose and deer.
He also referred to a 1996 article in the Wildlife Society Bulletin, a peer-reviewed scientific publication, that was based on a survey of state transportation agencies across the U.S.
It found that 91 per cent of respondents believed highway fencing was successful in preventing highway collisions. That compared to 63 per cent for underpasses or overpasses, 24 per cent for public awareness efforts and 17 per cent for "habitat alteration," which may include brush cutting. Just seven per cent thought warning signs were successful and zero per cent said lower driving speeds or highway lighting worked.
Brush clearing can have the unintended consequence of actually attracting wildlife to roadways, Clevenger testified.
The lawsuit is led by victims of moose-vehicle crashes. It involves 135 plaintiffs, including at least 15 estates of those killed in collisions since 2001.
The class was limited to injuries that required hospital admission. Plaintiffs are claiming unspecified damages as they seek to prove the province is liable for not doing more to limit risks created after the government introduced moose, a non-native species, to the island of Newfoundland more than a century ago.
Clevenger said Newfoundland now has the highest moose density rate in North America with an average of 1.7 moose per square kilometre. Up to seven moose will be found per square kilometre in the most populated regions, he said.
Clevenger said an average of about 660 moose-vehicle collisions happen each year.
He said the latest research advises prevention efforts, such as fencing, be focused on "hot spots" where the most crashes occur. Such statistics can be drawn from transportation reports of animal road kill and police responses to accident scenes, he said.
The province is defending its prevention efforts, including a limited fencing pilot project, more hunting licences, brush cutting, public awareness campaigns and roadside warning devices.
Plaintiffs say those measures weren't enough.
Proceedings started last Wednesday with testimony from Ben Bellows, who became a quadriplegic after his car hit a moose in 2003, and Jennifer Pilgrim, whose husband Roy died in 2009 when his vehicle collided with a moose.
Adult moose weigh between 360 and 450 kilograms. The top-heavy animals tend to race onto roads with little or no warning and often crash over the hoods of vehicles into the windshield.
The case is expected to be heard over three weeks.