You will know for sure when you see him up close and personal. He looks like a big deer. So who is to say the ears aren't 16" wide. I've got a deer on my wall with the ears in the alert position and his are 16 1/2 inches.
But looking at the mass he has, IMO, he's wider than 13.
This. I got to looking at my best deer on the wall and where his horns were in relation to his ears. They were right at them, so I took out the tape and measured the spread again. It was 17.5 inches. Then I measured from ear tip to ear tip. It was almost 15"!