Hamilton quickest in first practice
Lewis Hamilton laid down an early marker at the start of the Canadian Grand Prix weekend, setting the fastest time of the opening session of free practice at the Circuit Gilles Villeneuve.
Monaco GP winner Mark Webber was fifth fastest but Jenson Button endured a tough first session, forced to sit out much of it due to an oil leak on his McLaren.
The session started dry but sporadic light rain made conditions slightly tricky on the yellow soft compounds, many drivers running over the final chicane.
As the light rain continued to fall, Mark Webber ran across the grass at turn five, shortly before Heikki Kovalainen got it all wrong into sector nine, sliding across the track and clattering into the barrier.
It made a mess of the right side of the Finn’s Caterham and brought out the red flag.
"It looked more dramatic than it was, I lost it on the exit and the rear clipped the wall," said Kovalainen. "It can happen sometimes.
"Hopefully we can get out in the second session and have some running."
With the weather radar showing heavier rain imminent, Kimi Raikkonen decided to buck the trend and experiment on the super soft tyres, team-mate Romain Grosjean following suit.
With the super softs the order of the day during the final 10 minutes, so the lap times tumbled, Vettel jumping ahead of Rosberg and Alonso late in the day.
The session also saw a bizarre mixture of wildlife on the circuit, starting with a fox running across the circuit at turn five, just before Grosjean’s Lotus zipped past.
The Canadian wildlife then nearly caught out Raikkonen as a squirrel decided to brave its luck, running across the track before a groundhog waddled slowly across moments later.