The Eastern, or mountain, bongo is the largest and heaviest forest antelope. Both female and male Eastern bongos have spiraled, u-shaped horns that grow up to 40 inches long, which they keep their entire lives. Since they live in dense forests, the horns of Eastern bongos usually point backward, allowing them to better navigate their surroundings. One Eastern bongo here at the Zoo has crossed horns — see if you can spot it!