We are a commune of inquiring, skeptical, politically centrist, capitalist, anglophile, traditionalist New England Yankee humans, humanoids, and animals with many interests beyond and above politics. Each of us has had a high-school education (or GED), but all had ADD so didn't pay attention very well, especially the dogs. Each one of us does "try my best to be just like I am," and none of us enjoys working for others, including for Maggie, from whom we receive neither a nickel nor a dime. Freedom from nags, cranks, government, do-gooders, control-freaks and idiots is all that we ask for.
That does not take speed of movement into account, though. Other complications: animals and fish gain efficiency per unit weight for additional weight. So, in the end, the answer is not too meaningful.
A person on a bicycle is one of the most efficient means of locomotion per unit distance.. followed I think by bees.
(I mean bees are in second place, not that a bicycle being chased by bees is the most efficient. although it does make you go faster)
That was my guess as well. Turkey buzzards are not only ugly but clutzy and clumsy on the ground which is why you often see their carcass along side road kill. But in the air they seem to soar effortlessly forever without moving anything but wing tip feathers.