Kay Holekamp, an MSU researcher and zoology professor, recently found that by studying the creatures’ skulls, the reason for this unique characteristic becomes clear.

Researchers found that because young spotted hyenas’ skulls take longer to develop in an already competitive feeding environment, females are forced to become more dominant.

“They have a tough diet and immensely strong jaws that they have to develop … (so) dominant moms are helpful,” said Barbara Lundrigan, associate zoology professor and curator of the bird and mammal collections at the MSU Museum.

Lundrigan works with skulls brought back from Holekamp’s study site in Kenya. She said because the juvenile spotted hyenas often are unable to capture their own food, their mothers have to take charge and do the work for them.

As a result, the young hyenas’ survival depends on their mothers’ dominance.

“Moms have to go to bat for their kids,” Holekamp said.

The findings are completely new, Holekamp said. She hopes other researchers will take this new information and see if it applies to other mammals.

Taking the research to the next level, graduate student Jennifer Smith is working at Holekamp’s lab on campus to learn more about how young spotted hyenas are maturing.

“Even after cubs reach reproductive maturity, adult females and their offspring continue to form coalitions and they continue to be one another’s allies,” Smith said. “It’s this coalition and support that follows through on the dominance that’s established.”

Smith said hyenas have unique skull morphology, as it takes a significant number of years for the skulls to reach fully functional forms. At maturity, skulls of adult spotted hyenas are designed to crack enormous bones, Holekamp said.

“What we’re seeing is that it does take these animals a long time before they have adult morphology and it’s something we can measure,” Lundrigan said.

An interesting introduction to the spotted hyena sparked Holekamp’s interest in researching the species. On a trip to East Africa in 1976, a spotted hyena captured and killed a wildebeest in front of her. This prompted Holekamp to seriously study the species she describes as “weird.”

“I think these animals are so interesting,” Holekamp said. “They appear to break the rules. … They are showing us that they are an exception to the rules.”