Female Mammals can be Heavier than Males: Challenging Traditional Notions

Contrary to the common belief that male mammals are always larger than females, there are some mammalian species that defy this norm.

A recent study published in Nature Communications found that in 16 per cent of the 400 mammalian species analyzed, females were actually heavier than males. This goes against the usual sexual dimorphism observed in mammals, where males are typically larger than females.

In nearly 39 per cent of the species, both genders had the same mass.

Lead researcher, Kaia Tombak from Purdue University, emphasized that there is no standard rule when it comes to size differences between male and female mammals.

While it is common for males to be larger in carnivores, primates, and even-toed hoofed animals, there are exceptions to this rule.

In 46 per cent of bat species studied, females were actually heavier than males. This could be attributed to the energy demands of flight and the need for females to carry their young during gestation.

The study also mentioned the "big mother" hypothesis, which suggests that larger females may produce healthier offspring that are more likely to survive and thrive.

This could explain why some female mammals are larger than their male counterparts.

However, these findings are only based on a small percentage of mammalian species, and researchers acknowledge that more studies are needed to fully understand the complexities of size differences in mammals. Evolutionary biologist, Robert Cox, noted that these findings highlight the diversity and uniqueness of animal species.

Overall, the study sheds light on how animals can vary greatly in terms of size and challenges the traditional notions of male dominance in the animal kingdom.