The easiest way to identify Kelly is by looking at her tail - she is missing the long hairs at the end of her tail. Additionally, her ears are more rough around the edge compared to Tara's.
Msholo is easily identified as the tallest and largest of the four elephants. He has the thickest tusks which usually feature visible black streaks.
Unlike Kelly, Tara has long hairs at the end of her tail. Her ears are smoother around the edges compared to Kelly and her belly droops down.
Titan is identifiable as the smaller of the two male elephants at Zoo Atlanta. He is similar in weight to the female elephants, but has a slightly different body shape. He and his tusks will continue growing for several more years.