Google doodle marks Earth Day 2011

Today is Earth Day 2011, and Google has marked the event with a flashy doodle.

The animated doodle responds to the mouse pointer in a number of different ways. Hovering over the river, for example, causes a salmon to leap upstream and get eaten by a bear.

There’s also a butterfly, turkey and a koala in trees, and a frog, lion and penguin to interact with. Certainly it’s one of Google’s busier doodles.

Earth Day is themed around “A billion acts of green”, a campaign to get folks around the world to perform a billion separate acts of environmental service.

Current pledges include walking to work, remembering to turn lights off and installing a solar pump on a rain harvesting system.

Thus far 102 million acts have been pledged, so the campaign is a tenth of the way there.

Google unleashed three doodles last week, two of which weren’t mere static pieces of art. One, commemorating Yuri Gagarin, was animated, and the Charlie Chaplin’s 122nd birthday celebration doodle consisted of a short video clip.