Bouncing Bongo!! by © William West, AFP/Getty Images, via gettyimages.com. A 2-week-old Eastern Bongo calf romps around at Sydney's Taronga Zoo. Bongos are critically endangered with as few as 75 remaining in small groups of 6 to 12 animals in their Kenyan upland range. Bongos are one of the largest species of antelope in the world and are recognised by their striking russet colour and large antlers which extend over their backs.