Gotta say old fashioned method is a little hard when that end is facing the opposite direction and is behind a hill.
I know ear hair is a good method. One is hairier than the other I just like to get them confused. Wait now I saw a photo recently where the zoo identified them together. I will search for that and get back to you.
So going through old archive pictures, I can definitely say that this is Vishnu. Wasn't able to tell through the ear hair, but through the horn. Asha has a much smoother horn, whereas Vishnu has a lot of nicks and uneven grooves.
I now disagree. Look on the zoo's facebook page under their photos. There is one identified as Asha on may 26, and she has as you said a very round horn with a slight tilt to the right (her right). This one has a rounded horn. Another photo of identified as Vishnu has a very angular horn. his photo is dated feb 27.
Ok, went through my archive photos again, and after completely exhausting myself, I can say that you are right TZFan. This is Asha. The crooked horn, along with that small bump at the frontal base confirms this.
Vishnu's horn is larger, and somewhat jagged along the side face his face.
