Why older whale dads are now winning the mating game

"As male numbers grew, age-related mating competition intensified. In later years, males 16 and older were more likely than expected to become fathers and disproportionately engaged in mating behaviors such as singing and escorting females."

"Scientists believe widespread whaling in the South Pacific, which continued into the 1970s and left fewer than 200 humpbacks, ultimately drove the shift in the age of whale fathers. With generations decimated among animals that can live as long as a century, female whales were most likely to encounter younger mates."

"The consequences of whaling are so much bigger and more long-term than we thought. We can mess things up in a hurry, but it takes a long time to recover."

Research on humpback whales in New Caledonia spanning two decades reveals that older males increasingly dominated mating as the population recovered from near-extinction caused by whaling. Comparing data from 2000-2008 when populations were smaller to 2009-2018 when they rebounded, scientists found males aged 16 and older disproportionately engaged in mating behaviors like singing and escorting females. Widespread whaling that continued into the 1970s decimated generations of whales, creating demographic imbalances. As populations recovered and younger males migrated into the region, they were outcompeted by older males in mating competition. This demonstrates how human-caused population collapse produces lasting effects on natural selection and species behavior patterns that extend far beyond initial recovery.

Read at The Washington Post