Looks like a muley tail. What leads one to surmise it's a cross?
Color variations do occur. The pic below is a yearling muley for sure and a product of a twin birthing. Nearest blacktails are about 150 miles away. Not the typical mule deer tail though.
Same buck the year before as a fawn with his sister, who was melanistic.
Their mom was a typically patterned muley and is to the far left below.
Can't make any claims as to who their father/s might have been although Cookie caught up with this guy about 25 miles away.
This fellow from a prior year was also a little strange. Had a black stripe from nose all the way down his back to the tip of his tail, but was muley all the way.
Cookie found him across 4 seasons but his existence is now uncertain.
Despite antler configuration, the below is also a solid mule deer trailing a doe through our back yard.
Takes a serious examination to definitively determine heritage. We do have some whitetails in northeast and western Oregon and a few along the Columbia River.
Once listened to a Geist presentation on deer evolution. As to gait when fleeing from danger, tongue in cheek he said mulie/whitetail crosses were totaly confused and just stood around.
We see both species fenced in on Montana's Bison Range, but haven't noted any obvious cross overs.