Size matters for apes with the largest noses
MALE monkeys with large noses have more females in their harems – proving that size does matter, according to a team of scientists.
Researchers studying proboscis monkeys in Malaysia found that males with exaggerated masculine traits, such as big noses, “serve as advertisements to females in mate selection”.
Those involved in the study from Cardiff University, Kyoto University and Sabah Wildlife Department and the Danau Girang Field Centre in Malaysia, say the evidence points to both male-male competition and female choice as contributing to the evolution of enlarged male noses.
Dr Sen Nathan, assistant director of Sabah Wildlife Department and a PHD student at Cardiff University and Danau Girang Field Centre, said explanations for the evolution of the primate’s sizeable snout had so far been gleaned more from folklore than from science.
Dr Ikki Matsuda, from Chubu University and Kyoto University in Japan, said: “In addition to finding that enlarged male noses serve as advertisements to females in mate selection, we also found that males with larger noses also tended to have larger body mass and testes.
“This suggests that nose enlargement is a reliable predictor of social dominance and high sperm count.” The researchers observed and took morphological measurements from proboscis monkeys in the Lower Kinabatangan Wildlife Sanctuary and recorded the vocalisations of male and female proboscis monkeys at three different zoos: Yokohama Zoo in Japan; Singapore Zoo; and Low Kawi Zoo in Borneo.
The study is published in the scientific journal Science Advances.