The answer will be posted at the bottom of this post on Monday evening.
Location: north of the arctic circle on the sandy edge of the Yukon River, Alaska in summer.
Hint: these tracks are both made by the same animal. It's an animal that has a representative species on in North & South America, Europe, Asia, & Africa.
Edited to add: Goodness! What was I thinking??? Of course, Chuck, they do not exist on the continent of Australia any more then they do on Antartica. I'm going to blame it on a late night...how embarassing!! Also, for those of you thinking bear, I add an additional hint that these footprints are only slightly bigger then those of a domestic house cat.
RESULTS: Congratulations to Froghair, Doris Rose, and Vicious W on guessing correctly! It is indeed the North American porcupine (Erethizon dorsatum). The broom like markings that Jen noticed is the dragging of the quills. Did you know that there are 27 documented species of porcupine?? I actually saw these guys (i.e. the ones who made these footprints) mating...it sounded awful. Now all I need is some sort of thing like DJ Kirkby has for the best caption for her Wordless Wednesdays; some sort of prize for the correct guessers! But your names announced here will have to do for now.