Walking for humans is one of the activities that makes us stand out from other two-legged and four-legged animals. Our body is designed for walking, and most naturalists agree that walking is what humans do best.
In Lyanda Haupt’s book, Crow Planet (http://www.amazon.com/Crow-Planet-Essential-Wisdom-Wilderness/dp/0316019100), she talks about how crows are different from other passerine (perching) birds in their upright walking posture. When crows are on the ground, they prefer to walk compared to most birds in their order which hop. Of course, they have a tail swagger, but I can think of a few humans who have a little swagger, too. We may have more in common with crows than we realize as you will find out in Lyanda’s book.