Lewis Hamilton described a visit Tuesday to parts of Australia ravaged by months-long bushfires as heartbreaking, saying it was "one of those days that really put things into perspective".

The six-time Formula One world champion, who starts his title defence at the season-opening Australian Grand Prix in Melbourne this weekend, is a passionate supporter of environmental and animal welfare issues. At the height of the bushfires, which have now been extinguished, he donated US$500,000 to "support the animals, wildlife volunteers and rural fire services" affected by the crisis. After arriving from London, he headed straight from Sydney airport to the New South Wales countryside to see the devastation wrought by the fires, which experts warned may have killed up to one billion creatures.