Subject: why are animals better at jumping?

i've noticed that humans can't jump worth crap whan compared to other animals. my pet bird makes jumps that would kill a human, and i've seen squirrels jump three times their height. i think this is because humans have two-sectioned legs, while those animals have three. seemingly in support of my theory is that other animals with two-sectioned legs are equally bad at vertical movement - rhinos, elephants and the like. so is this a good guess, or not?

Re: why are animals better at jumping?