Birds have some of the most elaborate and visually stunning mating dances in the animal kingdom. From bouncing bowerbirds to dancing manakins, birds use dance to communicate their fitness and attract a mate. But why do birds go to such efforts to dance for potential partners? Here we explore the evolutionary reasons behind avian mating dances and how they benefit the dancing bird.
What is a mating dance?
A mating dance, also called a courtship dance, is a series of movements, vocalizations, and displays by one bird to attract a mate. Mating dances serve as a way for birds to show off their fitness, strength, health, and suitability as a mate. The dances are directed at potential partners and help demonstrate that the dancing bird has good genes worth passing on to offspring.
Birds have evolved specialized feathers, wattles, combs, and beaks to enhance visual displays during mating dances. Dances incorporate flying, strutting, bouncing, spreading wings or tails, and vocalizations. Some birds also incorporate found objects into dances, like decorating display areas or offering the potential mate food or nest material.
The most elaborate dances are found in birds of paradise, manakins, hummingbirds, cranes, and grouse. But most bird species perform simpler visual displays, songs, or flights to impress prospective mates. These rituals have evolved through sexual selection – as female birds choose the most impressive dancers to mate with, elaborate mating behaviors are reinforced over generations.
Why do birds dance?
Birds dance during courtship for several key reasons:
- To demonstrate fitness. A bird who can dance energetically and well may have good cardiovascular health, coordination, strength, and stamina – traits that would help them survive and successfully raise young. Females assess dancing ability to gauge a male’s overall quality as a mate.
- To show off plumage and colors. Bright feathers, combs, and wattles are display adaptations that males have evolved specifically for visual courtship. Dances highlight colorful features and signal the male’s fitness.
- To display to rivals. Mating dances also signal to rival males that the dancing bird has claimed a display ground or nesting territory. The dance says ‘this spot and these females are mine.’
- To strengthen pair bonds. Dances help pairs assess mate compatibility and reinforce bonds through coordinated displays. Paired birds may continue dancing together long after mating.
- To attract attention. Loud chirps, wing sounds, and elaborate movements during dances attract the attention of female birds nearby and incite interest.
In most bird species, dancing ability correlates strongly with male quality, health, and suitability for parenting. Females who select the best dancers gain direct benefits like nest defense and feeding of young. They also gain indirect benefits like healthier or fitter offspring. The quality advertisement and mate selection functions of dance are why mating rituals evolved and persist in birds.
Examples of mating dances
Some examples of spectacular avian mating dances include:
Birds of Paradise
Male birds of paradise perform some of the most flamboyant courtship displays in the avian world. They have evolved bright colors, elaborate feathers, and specialized dancing arenas to attract mates. Different species have distinctive dances – the Standardwing Bird of Paradise does pendulum displays swinging its feathers side to side, while the Red Bird of Paradise has an intense jumping dance routine.
Manakins
Male manakins execute acrobatic dances that include complex jumps, rolls, flies, and shuffles. Some species dance in coordinated display teams. Females watch the dances, then select a male partner. The best dancers mate with the most females.
Grebes
Grebes perform synchronized mated pairs dances running over water. Pairs angle their necks, lift up out of the water, and run in parallel while paddling. These duets strengthen lifelong pair bonds.
Cranes
Cranes are known for their elegant and athletic dances. Pairs will mirror each other’s bobs, jumps, runs, and wing spreads. Cranes may also throw sticks and grass into the air during dances. Their large size and synchronized movements make crane dancing visually impressive.
Grouse
Male grouse congregate and compete in communal dancing grounds called leks. They make whooshing wing sounds, stamp feet, inflate red neck sacs, and strut to entice females. A dominant top dancer at the lek center typically mates with the most hens.
Frat birds
Some small songbirds like swallows, martins, and blackbirds engage in large, rowdy group dances called f rat displays. 10-100 males will fly in synchronized patterns and dive in formation to impress onlooking females.
Penguins
Though flightless, male penguins still perform elaborate courtship dances for females. Emperors and king penguins use vocal calls, splash displays, and tactile gestures to find a mate among thousands of birds. Pairs also vocally duet and display to strengthen bonds.
Albatrosses
Albatrosses have an intricate mating dance where pairs stand face to face, stretch head and neck upward, gently touch bills, then ritualistically bow, all while rhythmically vocalizing. These dances last for minutes or hours and reinforce lifelong pair bonds.
How mating dances evolved
For mating dances to evolve, there must be variation among individuals in dance ability, females must prefer the best dancers, and dance ability must relate to fitness. When these conditions are met, sexual selection through female mate choice will favor ever more proficient dancing males over generations.
Sexual selection arises because one sex, usually females, invests more in offspring and is choosier about their mating partners. Male birds invest only sperm in offspring, while females invest energy in producing and caring for eggs. Being choosier benefits the high-investing sex, so elaborate male dances evolve to appeal to discriminating females.
Across many generations, female preferences for the best dancers select for males with strong visual, vocal, and locomotor skills. Traits that improve dancing, like long tail feathers, bright colors, or coordination gradually enhance through this sexual selection process. Mating success and reproduction become tied to dancing prowess.
While dancing ability arises through sexual selection, it becomes a proxy signal for heritable male quality. Good dancers advertise that they have fitness-indicating traits – like health, energy, survival skills, developmental stability, and ability to defend territories or resources – that would aid offspring survival. So by assessing mates through dance, female birds gain both direct and indirect benefits.
Does dance ability relate to male quality?
Decades of research on birds supports the idea that mating dance displays reliably indicate male quality. Some evidence includes:
- In manakins and cichlids, dominant alpha males do the most elaborate dances and get favored access to females.
- Female satin bowerbirds inspect male dances and bower decorations closely before mating with the most proficient males.
- In many species, larger, stronger males do more vigorous, complex dances than smaller males.
- Male chukar partridgesinjected with testosterone do longer, more frequent dances and attract more mates.
- Healthy male red-capped manakins dance for longer periods with faster, smoother movements than malaria-infected males.
Plus, dance displays are often costly and condition-dependent, meaning only the fittest males can sustain vigorous dancing. Courtship is used by females to gauge many aspects of male quality.
Why don’t female birds dance?
Female birds tend not to evolve elaborate courtship dances because they do not gain the same benefits as choosy males. Females invest heavily in offspring through egg production and parenting duties. So they are selective about their mating partners, leading to competitive male dancing. Males invest only sperm, so have an incentive to mate widely, displaying and dancing to attract female attention.
However, monogamous bird species do often display together to assess pair compatibility and strengthen bonds. Both sexes may dance in cranes, albatrosses, grebes, gulls, penguins, and several other monogamous species. Just not with the same complexity or vigor as male courtship dances.
Conclusion
Mating dances allow birds to assess potential mates for quality, display their prowess, attract attention, and bond with partners. For birds, dancing equals fitness. Natural selection favors healthy, vigorous, high-quality birds who can put on the most impressive visual, vocal, and locomotor displays. Proficient dancing becomes tied to reproductive success. Females get fitter offspring, males get more mates. Generation after generation, sexual selection through female choice leads to increasingly elaborate courtship dances and rituals.