Older Male Humpback Whales Reclaim Reproductive Dominance as Populations Recover From Centuries of Whaling

St Andrews study finds older male humpback whales sire more offspring as populations recover from whaling. Discover the role of age in whale songs and reproduction.

By: AXL Media

Published: Feb 27, 2026, 1:16 PM EST

The Lasting Legacy of the Whaling Era

Commercial whaling decimated large whale populations globally, leaving behind a legacy that researchers are only now beginning to fully comprehend. Beyond the sheer reduction in numbers, the era of exploitation fundamentally altered the social and reproductive dynamics of surviving groups. New research published in Current Biology suggests that as populations rebound, the biological "baseline" is shifting back toward a more natural state. This transition is most evident in how age now dictates reproductive success among males, a factor that was previously obscured by a population dominated by younger individuals during the early stages of recovery.

Unlocking Life History Through Molecular Clocks

Humpback whales have never been observed mating in the wild, which historically made identifying paternity nearly impossible. To overcome this, an international team led by the Sea Mammal Research Unit at the University of St Andrews utilized two decades of data from a breeding ground in New Caledonia. By analyzing small skin samples, scientists applied genetic paternity tests and a sophisticated "epigenetic molecular clock." This tool allows researchers to estimate the chronological age of a whale by measuring specific chemical changes in its DNA, providing a precise map of the population’s maturing age structure over time.

The Competitive Advantage of Experience

The study found that as the humpback population in the South Pacific matured, older males became disproportionately successful at siring calves compared to their younger counterparts. Senior author Dr. Ellen Garland noted that this shift was accompanied by changes in behavior; older males were more frequently observed singing, escorting females, and engaging in physical competition. This suggests that the complex skills required for humpback mating—such as the composition of elaborate vocal displays and the physical stamina for escorting—may require years of refinement and experience to master.