Male kalutas pay big reproductive price

A new study has confirmed the male members of a small, relatively unknown, carnivorous marsupial found in the Pilbara dies after a single, intense breeding season.

The kaluta weighs between 20 and 40 grams and research from the University of Western Australia’s School of Biological Sciences has found males of the species don’t live to see their young due to their intense investment in reproduction.

Lead researcher Genevieve Hayes said the synchronised death — known as male semelparity — is the result of an immune system collapse.

“We found that female kalutas mate frequently and with different males and, in our study, a single litter of up to eight young could have as many as three fathers,” she said.

“That means that males also have to mate a lot, and have good quality sperm (and lots of it), to outcompete rival males.

“This intense investment in reproduction, evidenced by their large testes, appears to be fatal for males.”

The research found that the kaluta, so far, was the only arid region marsupial to have male semelparity.