Why are so many fossils of woolly mammoths young males?

Scientists studying the fossils of ancient woolly mammoths believe they've cracked the mystery of why so many are young males - and the answer is surprisingly close to home.

It appears that woolly mammoths and today's young males have at least one thing in common - without their moms, they were destined to wander the world alone before succumbing to an accidental death.

Many of the clueless young male mammoths got themselves into risky situations, and were swept into rivers, or fell through ice or bogs where they remained until scientists found them thousands of years later. That's according to research published Thursday in the journal Current Biology.


"Without the benefit of living in a herd led by an experienced female, male mammoths may have had a higher risk of dying in natural traps such as bogs, crevices, and lakes," study author Love Dalen said in a press release.

"It is highly likely that the remains that are found in Siberia these days have been preserved because they have been buried, and thus protected from weathering. The new findings imply that male mammoths more often died in a way that meant their remains were buried, perhaps by falling through lake ice in winter or getting stuck in bogs," he added.

Correspondingly female mammoths got on just fine without their male counterparts, as they were led by an older matriarch who was quite at home in her terrain and steered her herd away from treacherous areas.

Scientists used genomic data to determine the sex of 98 woolly mammoth fossils found in the frozen hinterland of Siberia and discovered that 69% of them were male.

"We were very surprised because there was no reason to expect a sex bias in the fossil record," researcher Patricia Pecnerova said.

Giant woolly mammoths disappeared around 4,000 years ago as the climate warmed and they increasingly became targets for human hunters.