What male bias in the mammoth fossil record says about the animal’s social groups

Male mammoths really had to watch their steps. More than two-thirds of woolly mammoth specimens recovered from several types of natural traps in Siberia came from males, researchers report November 2 in Current Biology.

Paleogenomicist Patrícia Pečnerová of the Swedish Museum of Natural History in Stockholm and her colleagues examined genomic data recovered from 98 mammoth bone, tooth, tusk and hair shaft specimens and found that 69 percent of their owners were male. Sex biases in fossil preservation are rare, and the sexes were almost certainly balanced at birth. So the researchers considered whether social and behavioral patterns might have meant that male mammoths more often died in such a way that their remains were buried and preserved, such as becoming trapped in a bog or falling through thin ice.

In modern elephants, herds of females and young live together, led by an experienced female, whereas males are more likely to live in bachelor groups or alone. That could result in more risk-taking behavior for those males. Woolly mammoths, the distant cousins of modern elephants, may have had the same social structures, the researchers suggest.

The study, the authors say, highlights how fossil genomic data can help illuminate the past social structures and behavior of extinct animals — and how existing fossils may not fully represent the original population.