Older male whales’ singing boosts mating success, study finds

Researchers now say age and experience are giving some humpback males a clear reproductive edge. A new international study finds that older male humpback whales are more likely to sire calves than their younger rivals — and the reason appears tied to how well they sing.

Using two decades of fieldwork in New Caledonia, scientists combined behavioral records, genetic paternity tests, and an epigenetic aging technique to reveal a shift in mating dynamics as whale populations rebound from commercial whaling. The result: a growing role for veteran males in producing the next generation.

Older males outperform younger rivals by singing better

The research team observed that as the humpback population recovered, the proportion of older males on the breeding grounds increased and so did their mating success. Instead of brute force alone, the advantage seems linked to complex vocal displays: the males that sang most effectively were the ones more often identified as fathers.

Older males were consistently more likely to be the genetic fathers of calves than the younger males present in the same breeding seasons. That pattern suggests that time—spent learning, refining song structure, and honing competitive strategies—translates into reproductive payoff.

How scientists tracked fathers: methods that connect song, age, and paternity

The study relied on long-term monitoring from a conservation NGO and a suite of modern lab techniques. Key elements included:

• Two decades of behavioral observations and photo-identification on New Caledonia breeding grounds.
• Small skin biopsies taken noninvasively for DNA testing to assign paternity.
• An epigenetic molecular clock using DNA methylation patterns to estimate the age of individual whales from those same skin samples.
• Acoustic records and field notes on male singing and escorting behaviors.

Together, these lines of evidence let researchers link who was singing, who was courting or escorting females, how old those males were, and whether they later turned out to be the fathers of observed calves.

What the epigenetic clock reveals

Traditional aging techniques for large marine mammals are limited, so the molecular clock represented a breakthrough. By measuring biochemical markers in skin samples, scientists could estimate each whale’s age with enough precision to track changing age structure across the population and relate age to reproductive success.

Why whaling’s legacy still shapes whale societies

Commercial whaling didn’t just reduce whale numbers; it altered population composition. After intense hunting, many recovering groups were skewed toward younger age classes. As numbers climbed back, the demographic mix changed — and with it, social and reproductive dynamics.

Scientists propose several explanations for the shift toward older males siring more offspring:

• Experience and learned skill: Older males may have had more time to perfect their songs and courtship tactics.
• Sexual selection intensifying: As the population rebounds, females might become choosier, favoring males with superior displays or the most consistent performance.
• Increased competition: Larger populations change how males compete, possibly amplifying advantages linked to age and skill.

Why humpback song matters: function, complexity, and learning

Humpback whales produce some of the most elaborate vocal performances in the animal world. Males sing long, structured sequences that can travel across vast stretches of ocean and are often heard throughout breeding areas.

Researchers think song serves multiple purposes: it may attract females, assert territory or status, and advertise stamina or skill to competitors. The new findings add weight to the idea that song quality is a meaningful component of mating success, not just background noise.

The implication: Singing is not purely instinctive—there appears to be a learning curve. Males may refine phrase structure, rhythm, and endurance over years, giving older singers a measurable advantage when females are choosing mates.

Observed behaviors tied to reproductive outcomes

Field observers recorded several mating-related behaviors that correlated with paternity:

• Escorting: males shadowing and protecting a female during breeding periods.
• Song output: duration and complexity of vocal displays while on breeding grounds.
• Physical contests: direct, sometimes intense interactions between rival males.

Older males were more often seen combining effective song with active escorting, a combination that frequently coincided with paternity results from genetic tests.

Broader implications for whale recovery and future research

The study highlights how population recovery can reshape social systems long after hunting stops. Changes in who breeds — driven by age, learned behaviors, and female choice — can influence genetic diversity and the evolutionary trajectory of recovering species.

Scientists are now able to explore questions that were once out of reach: how cultural traits like song evolve within populations, how age structure affects reproductive success, and what factors drive female choice in large marine mammals. Continued monitoring and the integration of acoustic, behavioral, and molecular tools are central to those efforts.

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Michael Thompson

Michael Thompson is an experienced journalist covering U.S. and global news. With ten years on the front lines, he breaks down political and economic stories that matter. His precise writing and keen attention to detail help you grasp the real‑world impact of every event.