This ability to choose goes beyond behavior. It influences the health of the flock, the direction of genetic traits, and the dynamics of chicken communities. It’s a reminder that even in the barnyard, evolution is not just about survival of the fittest—it’s about choice, especially female choice.

Courtship and Criteria: What Hens Look For

Long before mating takes place, hens observe and assess the roosters in their environment. This evaluation begins with courtship behavior, which can include:

• Tidbitting: A rooster clucks and offers food to a hen as a sign of both provision and attentiveness.

• Dance displays: Roosters circle hens with outstretched wings, performing what’s known as a “waltz.”

• Gentle pecking: When non-aggressive and ritualized, this behavior is often part of bonding and pre-mating signaling.

Hens respond more favorably to roosters who are attentive, non-aggressive, and active in courtship. A rooster who merely chases or dominates may succeed in short-term mating attempts, but hens have ways of ensuring that only the best males pass on their genes.

The Power of the Crow

One of the most remarkable tools hens use to assess mates is vocal selection. Research has shown that hens prefer the crows of dominant, healthy roosters. These vocalizations signal a rooster’s vitality and status in the flock.

Roosters with deeper, stronger, and more consistent crows tend to be favored. In wild red junglefowl—the wild ancestors of domestic chickens—rooster calls serve as honest indicators of age, health, and testosterone levels. Domestic hens appear to have retained this preference, indicating that sound plays a key role in mate selection.

Appearance and Physical Traits

Like many animals, chickens also rely on visual cues. Hens tend to favor:

• Bright, even comb color: A red, healthy-looking comb signals good circulation and robust health.

• Symmetry: Just as in other species, symmetrical features may indicate developmental stability.

• Feather quality: A sleek, well-groomed appearance suggests a parasite-free and genetically fit rooster.

These visual preferences are not arbitrary. They are rooted in evolutionary success. A hen choosing a vibrant, well-kept rooster is more likely to produce strong, resilient offspring.

Sperm Ejection: The Ultimate Choice

Perhaps the most surprising and fascinating aspect of hen mate selection happens after mating. Hens have the ability to eject sperm from undesirable roosters. This phenomenon, called cryptic female choice, allows them to retain control over fertilization even after insemination.

In a 2009 study published in The American Naturalist, researchers observed that hens were more likely to eject sperm from subordinate or genetically similar males, favoring instead sperm from dominant, unrelated roosters. This mechanism helps maintain genetic diversity and reduces the risk of inbreeding.

Sperm ejection is both a behavioral and physiological process. After mating, hens contract their cloacal muscles, physically expelling unwanted sperm. This ensures that actual fertilization aligns with their selective preferences.

Evolutionary Implications

The ability of hens to choose their mates—and override undesired fertilization—has profound evolutionary consequences. It places female agency at the center of avian reproduction. Rather than being recipients of whichever male manages to mount them, hens actively shape the genetic future of their offspring and the flock.

In natural settings, this leads to more balanced social dynamics and stronger group health. In domesticated settings, it means that flock behavior, rooster temperament, and mating patterns are all shaped in part by female preferences, not just human breeding choices.

What This Means for Chicken Keepers

Understanding that hens make deliberate mating choices can inform how backyard keepers and small-scale breeders manage their flocks:

• Rooster-to-hen ratios matter: Too many roosters can lead to stress and forced mating. A lower ratio allows hens the space to choose.

• Observe courtship behaviors: If a rooster is aggressive or domineering, hens may not accept him. This can lead to poor fertility or stress.

• Trust the hen’s instincts: If a hen avoids or ejects sperm from a certain rooster, it may be an indicator of his health, genetics, or social standing.

Recognizing and respecting the agency of hens leads to healthier, more harmonious flocks—and ultimately better breeding outcomes.

Conclusion

The myth of the domineering rooster and the passive hen doesn’t hold up under scientific scrutiny. Hens are powerful decision-makers, equipped with behavioral, sensory, and physiological tools to select the best mate. From assessing comb color and courtship dances to evaluating crows and rejecting unwanted sperm, the hen plays an active, intelligent role in reproduction.

This level of choice isn’t just a curiosity—it’s a testament to the complexity of avian social structures and the subtle ways that evolution continues to operate, right under our beaks.