Bird Courtship

It’s spring again—and love is in the air! Winter plumages are shed by many to reveal striking, gaudy birds. Breeding males usually take on an exorbitantly ostentatious appearance, abandoning the comforts of a camouflaged plumage to attract a mate. The extremely selective females are part of the natural selection committee, looking for the strongest, most well-adapted male to mate with. For some birds, the relationship (or relationships in polygamous birds) is seasonal, but for others, a mate chosen is for life.
Grebes, in the family Podicipedidae, are especially known for their elegant courtship rituals. I was very fortunate to witness Clark’s Grebes and Western Grebes at Lake Cachuma in the Santa Ynez Valley of California. With Serengeti-esque chaparral habitats surrounding the lake, witnessing hundreds of these birds during their breeding season was amazing. Clark’s Grebes were generally thought to be a pale form of the Western Grebe up until the 1980s when DNA testing distinguished them as separate species. Both grebes tend to congregate together in large groups. I was elated to see two Clark’s Grebes perform what is called a “Rushing Ceremony.” The Klamath Bird Observatory describes the elaborate ritual extremely well:

"Named elements of the courtship display of the Western [and Clark's] Grebe. Clockwise from upper left:rushing, weed-dancing, dip-shaking and bob-preening." Diagram  courtesy of Stanford University.

“Named elements of the courtship display of the Western [and Clark’s] Grebe. Clockwise from upper left: rushing, weed-dancing, dip-shaking and bob-preening. (Ehrlich et. al., 1988).

“The ‘Rushing Ceremony’ consists of advertising calls made to a potential mate, dip-shaking where heads are dipped into the water and shaken on the way out, rushing wherein pairs run on the surface of the water side by side flapping their wings, and finally diving head first into the water.” (Ehrlich et. al., 1988)

Two Clark's Grebes (Aechmophorus clarkii) preforming the "Rushing Ceremony." The genus name Aechmophorus, originates from Ancient Greece. The Greek aichme, meaning "spear," and phoros, meaning "one who bears something," create a combined meaning of "spear-bearer," referring to the distinctive, dagger-like beaks.

Two Clark’s Grebes (Aechmophorus clarkii) preforming the “Rushing Ceremony.” The genus name Aechmophorus, originates from ancient Greece. The Greek aichme, meaning “spear,” and phoros, meaning “one who bears something,” create a combined meaning of “spear-bearer,” referring to the dagger-like beaks characteristic of grebes and loons. Photo by Jacob Gorneau.


Although many people don’t think of crows when they think of bird courtship, crows have a courtship similar to other birds. The courtship entails in-flight performances and, as the Connecticut Department of Energy and Environmental Protection describes, “a dance involving bowing, strutting with spread wings and tail and a general puffing of the feather coat.” Due to the wariness of such intelligent birds, this behavior is seldom observed.
This diagram, courtesy of Eastern Kentucky University, shows the traits female birds generally look for in males.

This diagram, courtesy of Eastern Kentucky University, shows the traits female birds generally look for in males. Unsurprisingly, females also consider relatedness, as it would be much more beneficial to increase variation within a species by breeding with lesser-related males.


Contrary to crows, many birds, especially in the New World Warbler family (Parulidae), rely more on vibrant colors and elegant songs rather than physical displays. Emerging from a much less colorful nonbreeding plumage, male warblers court with sweet songs and contrasting flamboyant colors. The Yellow Warbler, Setophaga petechia, is known to sing nearly 3,240 songs in one day of breeding season, according to BioKIDS! In comparison, the Red-eyed Vireo, Vireo olivaceus, can sing up to 20,000 songs a day (Cornell Lab of Ornithology)! Talk about determination! The photo above, from Eastern Kentucky University shows the features many males flaunt to achieve reproductive success, and thus succeed in passing on its unique traits to its offspring.
A gorgeous Red-eye Vireo (Vireo olivaceus) captured by Gordon Dietzman of Project Noah.

A gorgeous Red-eyed Vireo (Vireo olivaceus) captured by Gordon Dietzman of Project Noah.


James Parry explains the biology behind birdsong:

“The sound of a male bird in song triggers the secretion of sex hormones in a female of the same species, which encourage her into breeding condition and prompt her instincts to mate and build a nest. Although the females of some species are indeed known to sing, such activity is usually reserved for the non-breeding season. For most songbird species the female has no song of her own and is simply reactive to that of the male. She assesses it in terms of strength, variety, and proficiency of delivery, and makes her choice of mate accordingly. He who sings best usually wins the day.” (Parry, The Mating Lives of Birds, page 26, 2012)

The male Common Yellowthroat (Geothlypis trichas, left) and the male Yellow Warbler (Setophaga petechia, right) are quintessential examples of the vibrant colors warblers in the family Parulidae don to attract mates. Photos by Jacob Gorneau.

The male Common Yellowthroat (Geothlypis trichas, left) and the male Yellow Warbler (Setophaga petechia, right) are quintessential examples of the vibrant colors warblers in the family Parulidae don to attract mates. Photos by Jacob Gorneau.


According to Paul A. Johnsgard, ducks in the genus Anas each have characteristic courting behaviors to distinguish each other since they can appear so visually similar. Due to their similarity in appearance, hybridization is not uncommon in areas where the ranges of Anas species overlap.
The Cornell Lab of Ornithology notes that the Dickcissel (Spiza americana) is known to spend 70% of the day singing—courting for females and ardently defending its territory from other males!
The Dickcissel (Spiza americana) is a grassland nesting bird with a more western distribution than the Bobolink but has similar problems nonetheless. Photo by Alexandra Forsythe.

The Dickcissel (Spiza americana) is a grassland nesting bird with a midwestern distribution in North America. Photo by Alexandra Forsythe.


Non-songbirds, such as woodpeckers in the family Picidae, like the Yellow-bellied Sapsucker, have distinctive “drums” which allow them to attract a mate.
The Yellow-bellied Sapsucker (Sphyrapicus varius) is one of a number of woodpeckers that have a brush-like tongue to catch sap from trees through capillary action. This individual is a male, characterized by the red crown and throat. Photo by Jacob Gorneau.

The Yellow-bellied Sapsucker (Sphyrapicus varius) is one of a number of woodpeckers that catches sap from trees through capillary action. This individual is a male, characterized by the red crown and throat. Photo by Jacob Gorneau.


Another very common behavior in courtship is courtship feeding. Males generally feed their female mates. Northern Cardinals (Cardinalis cardinalis), warblers, finches, and terns, among others, all regularly display this behavior. The male feeds the female to ensure she is healthy to lay their offspring, contributing to the progression of both birds’ traits.
Although the behavior of birds during courtship and breeding season may be amazing, the biology behind the scenes is just as marvelous! The female selects only the best—she is a driving force in the natural selection and the future of the species. The complex songs and beautiful dances can be broken down into a series of instinctive behaviors, essential in the preservation of the genes the two birds possess, and essential in the preservation of the species as a whole.
References

2014-04-25T10:25:22+00:00