Here is an excerpt from a Discovery News Report:
In a piece of experimental archaeology, a team of local and U.S. researchers showed that the massive statues, known as moai, can be moved from side to side by a small number of people, just as one might move a fridge.
"We constructed a precise three-dimensional 4.35 metric ton replica of an actual statue and demonstrated how positioning the center of mass allowed it to fall forward and rock from side to side causing it to 'walk,'" Carl Lipo, an archaeologist at California State University, Long Beach, and colleagues wrote in the Journal of Archaeological Science.
The report also states this:
According to Lipo, the position of the incomplete road moai shows that they fell over from upright positions, contradicting the theory that they were horizontally rolled on logs.
"The majority of statues are found facedown when the road slopes downhill, and often on their backs when going uphill," he said.With that in mind, this walking theory really makes a lot of sense.
Here is a video of a moai replica being 'walked'.
I can totally see these statues being moved this way after watching the video. They almost make it look easy. Although the Discovery News report says this is a new theory (as well as other reports I saw when I googled for more information), the video below mentions it and it was uploaded in 2009, so it must not be all that that new. It says the walking the statue into position could have damaged the bottom of the statue, but considering it was recently reported that the statues have bodies that go deeper underground than previously thought, maybe they weren't actually looking at the bottom of the statue at the time. And even if they were, who's to say that any damage the statue sustained while being moved wasn't repaired once it was set in place? If they can make the statues, surely they can repair them too, right?
The way they moved the statue on the logs towards the end of that clip does look like a fairly efficient way of moving the statues too, but as the narrator points out, that was on flat terrain. Moving it that way on rugged terrain may not have been so simple. Considering that statues found facedown are going downhill and the ones on their back going uphill, the walking theory seems to be the more likely of the two theories.