Labors of Love

Avian courtship displays are some of the most elaborate of any animal species. While no scientist has established why, some theories suggest that, unlike groups such as Mammals or Insects, Birds don’t have a strong sense of smell. Instead, they must rely on their extraordinary eyesight and hearing to identify and assess potential mates. 

In general, because of a higher biological cost, the female of many species chooses her mate. This also applies to Birds. Because most Birds hatch naked and helpless (what’s known as altriciality), ensuring you’ve picked a good partner to raise the kids with is extremely important.

However, not all altricial species exhibit biparental care. When food is abundant, uniparental care becomes more viable and, when males don’t have to spend energy raising young, they can pour it instead into colorful (sometimes outlandish) plumage and incredibly complex displays. This is the case with Hummingbirds with their iridescent throat feathers and death-defying dives. It also applies to the Manakins of Central and South America. 

Because the male Manakin’s involvement with the next generation ends after mating, females are looking for evidence of strong genetics to pass on to their chicks. These genetics can be demonstrated through qualities such as stamina and beauty, and the Lance-tailed Manakin’s courtship display has both in spades. 

First, the little black, blue, and red-capped bird employs the services of a wingman to woo the ladies. During their precisely-choreographed routine, the duo leapfrog backwards over each other while simultaneously singing a duet. 

In altricial species, uniparental care is relatively rare, but it’s common in precocial species where chicks leave the nest immediately upon hatching. These include Waterfowl, Shorebirds, and Galliformes like Turkeys, Pheasants, and Grouse. Grouse, in particular, have some of the most well-studied courtship displays because of their fidelity to gathering sites called leks. 

For a Grouse like the Greater Prairie-chicken, a ground Bird living in a sea of grass, lekking is a way to locate potential mates. Leks also allow females the opportunity to evaluate many potential mates at once. 

During his display, a male Greater Prairie-chicken inflates the orange air sacs on either side of his neck to produce a booming sound, which can be heard up to half a mile away. His dance consists of a rapid series of stomps with his tail and wings fanned, while he simultaneously raises feathers called pinnae that look like horns. Only the best performers at a lek earn the right to mate.

But just as not all altricial species exhibit biparental care, not all precocial species exhibit uniparental care. Biparental care is advantageous because it ensures more chicks survive to adulthood, which is especially important for species with small clutch sizes. For example, both Western Grebe parents (a precocial species) are invested in the care of their young. This is probably because the grebes lay an average of 3 to 4 eggs. By contrast, Greater Prairie-chickens average 12 to 13 eggs. 

Western Grebes’ courtship displays not only have to demonstrate physical fitness then, but also the male’s suitability as a provider. He does this by giving gifts, as well as performing a synchronized ballet with the female including preening, head shakes, and, most spectacularly, what’s known as the “rushing ceremony” where the pair dash across the surface of the water side by side. 

While we’ve only talked about males as performers and females as choosers, some species, like the Spotted Sandpiper, flip the script. Bigger and more aggressive than the male, the female is the one that woos. She does so in a dynamic display of chest puffing and strutting, all while flaring her tail and pushing out her wings. If she is successful, after they mate and she lays eggs, he’ll incubate them and protect the resulting chicks while she goes on to mate with another male. 

The Bird world has a wide variety of these often beautiful, sometimes bizarre, courtship strategies. The only rule? That there is no rule. From dancing, to strutting, to chest booming, to nest building, they sure do make flowers and candlelit dinners look pretty tame by comparison!