It’s not just the men who flex their biceps to impress the opposite sex, kangaroos do it too! Male kangaroos frequently adopt poses to show off their muscular arms to females, a new study has found. Researchers sad a male kangaroo’s forearm size could be a sexually selected trait and help them find a mate.
The research by Murdoch University and Curtin University in Australia centered on data gained from dissecting 13 grey kangaroo males and 15 females. Researchers found the arm and shoulder muscles of male kangaroos play a key role in attracting members of the opposite sex.
Dr. Natalie Warburton and collaborators Dr. Trish Fleming and Dr. Bill Bateman used a number of criteria to confirm their conclusion that forelimb musculature was a sexually-selected trait.
“Forelimb measurements showed that whereas female musculature growth was proportional to body size, male musculature was exaggerated,” she said. “Ths could be linked to the fact that male kangaroos establish their dominance hierarchy through sparring contests. Males at the top of the hierarchy have higher mating success.”