Dominant female spotted hyenas give their young a head start in life by passing on hormones that make their cubs more aggressive and likely to survive, researchers said Wednesday.
They have shown that alpha hyena mothers have higher than normal levels of the male hormone androgen late in pregnancy — which they pass on to their cubs, enabling them to become top dogs.
Androgen is linked to male characteristics such as muscle development, aggression and sexual behaviour.
"What this means is that there are gifts a mom can give to her baby," Kay Holekamp of Michigan State University said in a written statement. "She can manipulate her offspring's behavior and help her kids to survive and reproduce successfully by transferring status-related traits via prenatal hormone exposure."
Holekamp and her colleagues discovered the animals' secrets while studying wild spotted hyenas in Kenya over two decades. Their findings are reported in the Thursday's issue of the journal Nature.
Spotted hyenas live in a female-dominated society. Females are bigger than males and more dominant. Their reproductive organs are similar, which makes it difficult to determine their sex and awkward for the animals to mate.
"You don't find many mammals where the female is boss," said Holekamp.
Although females have masculine traits and unusual reproductive organs, they still maintain some female characteristics. The hormones from the top-ranking mother enables her female cubs to attain the same status and be superior hunters.
Male offspring born to high-status mothers are also more aggressive, according to the researchers.
