The ICR piece also displays a willful misunderstanding of the terms used in the PLoS article, and indeed a refusal to acknowledge what we can observe on any nature documentary and/or by observing neighborhood cats. I volunteer at a wolf sanctuary, and there are plenty of cats in my neighborhood, and I know from observation that both species, when they are simply moving from A to B, walk. Devoid of context, that is their most efficient mode of locomotion. If running were more efficient, these critters would run everywhere. But they don’t. What the PLoS study compares is modes of locomotion while attempting to capture prey, and whether a predator chases its prey or stalks it, the means of locomotion in question is never going to be as efficient–as a means from getting from A to B–as walking, but the point is that the object of any prey-acquiring mode of locomotion is more energy-efficient in that its ultimate goal is to acquire more energy (in the form of food) than was expended in capturing it.

It strikes me as plausible that the mode of prey-acquiring locomotion is determined largely by the behavior of the prey. Cheetas and wolves go after ungulates, which arem’t going to dive into a burrow to escape but can run for respectable distances, so thre is a point to the predators running them down. Domestic cats, on the otherhands, tend to go after small birds and rodents, which have the means to place themselves beyond the cat’s reach quite quickly, so it is ultimately more efficient for the cat to stalk them, because that is how the cat stands the best chance of actually catching them. A means of locomotion that uses les energy but doesn’t actually result in the predator catching its prey is not efficient, in that there’s no payoff for the energy expended.