Sentence:  The number of prairie dogs was absolutely astounding. ... Some of the bolder dogs—though in fact they are no dogs at all, but little marmots rather smaller than a rabbit—would sit yelping at us on the top of their mounds, jerking their tails emphatically with every shrill cry they uttered. As the danger grew nearer they would <WSD>wheel about</WSD>, toss their heels into the air, and dive in a twinkling down into their burrows. 
Meaning of the word marked with <WSD> tags:  To change direction quickly, turn, pivot, whirl about.