A Group of Proboscis Monkeys (IMAGE) Kyoto University Caption Male proboscis monkeys weigh about 20 kilograms while females are roughly half that. The long nose is only found in males. Credit Kyoto University / Masuda Lab Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.