 Sexual dimorphism is most pronounced in saddleback populations in which males have more angled and higher front openings , giving a more extreme saddled appearance . Males of all varieties generally have longer tails and shorter , concave <unk> with thickened knobs at the back edge to facilitate mating . Males are larger than females — adult males weigh around 272 – 317 kg ( 600 – 699 lb ) while females are 136 – 181 kg ( 300 – 399 lb ) . 
